July-August 2023

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 49 Figure 5: Wilson’s Technique. Figure 6: Cohen’s Technique. the intact sclera, where it is tied by performing a 4-throw knot (Figure-8). This technique allows for both the release and adjustment of tension on the surgical site, ensuring optimal outcomes and reducing the risk of complications. Subspeciality - Glaucoma

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 50 Figure 7: Kolker’s Technique. Figure 8: Releasable cum adjustable suture. Complications The presence of a suture loop at the corneal surface can act as a nidus for infection. Additionally, unburied releasable suture ends have the potential to cause windshield-wiper keratopathy due to friction with lid movements. Releasing the sutures may be difficult in cases of excessive fibrosis. Moreover, excessive shearing stress during suture removal can result in flap tears and leakage through the needle track at the limbus. It is also important to be aware that epithelial abrasion and subconjunctival bleeding may occur following the release of the sutures. The appropriate time to remove releasable sutures can vary based on individual patient factors and surgeon preference. However, according to the literature, releasable sutures are typically removed within 2 to 4 weeks after trabeculectomy surgery.[17] It is important to note that the decision for suture removal should be made by the surgeon based on the patient’s clinical condition, wound healing progress, and intraocular pressure control. Use of Antifibrotics Antifibrotic agents, such as 5 Fluorouracil (5FU) and mitomycin C (MMC), are used in glaucoma filtration surgery to prevent excessive scarring and improve surgical outcomes. These agents modify the activity of fibroblasts and prevent their proliferation, reducing the risk of scarring under the conjunctiva.[18] To achieve optimal results, antimetabolites like MMC should be applied over a large area to promote the formation of a diffuse bleb and prevent the formation of a “ring of steel” scarring. Polyvinyl alcohol (PVA) sponges soaked in the antifibrotic agent Subspeciality - Glaucoma

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 51 Intraoperative use of MMC has shown improved outcomes and reduced reliance on postoperative IOP-lowering medications.[27] It is particularly beneficial in patients at high risk of surgical failure, such as those undergoing combined cataractglaucoma surgery or with a history of failed trabeculectomy. Additionally, MMC is also used postoperatively for needling procedures in failing or failed blebs, with a commonly used dose of 0.1-0.3 mg/ml of MMC.[28] Overall, the use of MMC in glaucoma surgery has demonstrated positive results in terms of surgical success, reduced scarring, and the rescue of failing blebs when used postoperatively. are preferable to methylcellulose sponges, as the latter tend to fragment beneath the surgical flap.[19] MMC Mitomycin C (MMC), produced by the bacterium Streptomyces caespitosus, is an antitumor antibiotic that inhibits DNA, RNA, and protein synthesis.[20] In glaucoma filtration surgery, MMC is used as an antifibrotic agent to prevent excessive scarring and promote the formation of a diffuse and posterior bleb. The recommended dosage of MMC for primary trabeculectomy is typically between 0.2 to 0.5 mg/ml, applied for a duration of 2 minutes.[21] Studies have shown that extending the application time beyond 2-2.5 minutes does not significantly increase its efficacy.[22-24] We routinely use 0.02% MMC for 2 minutes. MMC is applied between the conjunctiva-tenons and the sclera, and it can also be applied beneath the scleral flap itself. After MMC application, thorough irrigation with 30cc saline is performed. The most common method of MMC application is the sponge-soaked method, where a sponge soaked in MMC is used (Figure-9). However, sub-tenon injection of MMC has gained popularity due to its ability to provide a larger area of application, resulting in diffuse elevated blebs with less vascularization and scarring.[25] Sub-tenon injection offers a more predictable dose of drug delivery and facilitates easier dissection by making the tenons more tumescent with reduced conjunctival damage.[26] 5- Fluorouracil 5-Fluorouracil (5FU) is an antifibrotic agent that acts by inhibiting thymidine synthesis, leading to cell death in the S phase of the cell cycle.[29] It has an anti-fibroblastic action and interferes with pyrimidine metabolism. Compared to Mitomycin C (MMC), 5FU has less direct DNA damage, resulting in lower efficacy.[30,31] In laboratory studies, a single application of MMC has been shown to inhibit fibroblast growth for up to 1 month, while the effect of 5FU disappeared after 7 days.[32] The usual intraoperative dose of 5FU is 25-50mg/ml for 5 minutes, applied under scleral or conjunctival flaps.[33] Alternatively, postoperative subconjunctival injections of 5FU (5 mg in 0.1 to 0.5 ml of saline) can be used, but frequent injections may be required.[30] MMC is clinically more effective than 5FU, but it is associated with higher risks of thin cystic avascular blebs and postoperative endophthalmitis.[34] On the other hand, 5FU is more frequently associated with corneal epithelial toxicity and uveitis.[35,36] However, MMC has clear advantages over 5FU in patients at high risk of surgical failure.[37] Ologen The ologen implant is a biodegradable collagen implant made from porcine-derived atelocollagen (90%) and glycosaminoglycans (10%).[4] The ologen implant is directly placed over the scleral flap before conjunctival closure with aim of preventing sub conjunctival fibrosis. It promotes tissue remodeling and prevents scar tissue formation while mechanically separating and preventing adhesions between episcleral and conjunctiva. Studies comparing the efficacy of ologen with Mitomycin C (MMC) in trabeculectomy have yielded mixed results.[38-41] A recent meta-analysis of six randomized controlled trials showed comparable overall success rates between the ologen and MMC groups, although the ologen group had a slightly lower success rate numerically (78.4% vs 86.6%).[42] However, this difference was not statistically significant. Ologen was found to be less effective in controlling intraocular pressure (IOP) compared to MMC, possibly due to its lack of antifibrotic properties and a potential tissue reaction around the implant in the subconjunctival space. The incidence of complications was similar between the two groups. Some studies have explored the use of ologen in combination with MMC to prevent hypotony, and these have shown promising results.[43,44] Further research is needed to fully understand the efficacy and potential benefits of using ologen in glaucoma filtration surgery. VEGF Increased levels of VEGF have been observed in the aqueous humor of patients undergoing glaucoma filtration surgery.[27] VEGF plays a role in angiogenesis, fibroblast migration, and inflammatory cell migration, which can contribute to the formation of a fibrotic bleb and surgical failure. Bevacizumab, a non-selective VEGF inhibitor, is commonly used as an anti-VEGF agent in glaucoma surgery. Figure 9: MMC soaked sponges (0.02%) used for 2 minutes followed by copious wash with 30 cc RL/BSS. Subspeciality - Glaucoma

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 52 Anti-VEGF agents can be administered through various routes, including subconjunctival, intracameral, or intravitreal injections. Subconjunctival injection is the most commonly used route, with doses of 2.5 or 5mg of bevacizumab being typical.[18] The use of anti-VEGF agents has been particularly emphasized in cases of neovascular glaucoma (NVG) undergoing filtration surgery, as intracameral injection of anti-VEGF agents (1.25mg/0.01ml) can help resolve iris/angle neovascularization.[27,45] In other forms of glaucoma, studies have explored the role of antiVEGF agents as an adjunct or alternative to MMC (mitomycin C).[46-48] One recent randomized controlled trial compared postoperative subconjunctival injection of bevacizumab with placebo in primary trabeculectomies using MMC.[49] The study found no significant differences in postoperative IOP or the need for glaucoma medications between the two groups at one year. However, patients who received bevacizumab injections had better bleb morphology and success rates, although these differences were not statistically significant. Overall, the use of anti-VEGF agents in glaucoma filtration surgery, particularly bevacizumab, has shown potential benefits in terms of improving bleb morphology and success rates. However, more research is needed to determine the optimal dosing, timing, and long-term effects of anti-VEGF agents as adjunctive therapy or alternatives to MMC in glaucoma surgery. Other Innovation The EX-PRESS Glaucoma Filtration Device, approved by the FDA in 2002, is a stainless steel, non-valved implant used to divert aqueous humor from the anterior chamber to a subconjunctival filtration bleb.[50] Originally, it was placed directly under the conjunctiva, but this approach led to complications. To address this, the procedure was modified by placing the device under a partial-thickness scleral flap, reducing the risk of hypotony, erosion, and extrusion. The modified technique has been widely adopted and is now the recommended method for device placement. The device comes in two sizes, with either a 50 or 200 µm internal lumen, and has demonstrated biocompatibility in animal studies. This innovative approach offers a potential solution for safer and more effective glaucoma filtration surgery. Conclusion Changes in surgical techniques have been implemented to optimize the success of trabeculectomy procedures. For example, surgeons now pay greater attention to factors such as the size and shape of the scleral flap, the location and size of the trabeculectomy opening, and the management of intraocular pressure during and after the surgery. These refinements have contributed to better surgical outcomes and a reduced incidence of complications. Continued research and innovation in this field hold promise for further advancements in the future. References 1. Allison K, Patel D, Alabi O. Epidemiology of Glaucoma : The Past, Present, and Predictions for the Future. 2020;12(11). 2. Thomas S, Hodge W, Malvankar-mehta M. The Cost-Effectiveness Analysis of Teleglaucoma Screening Device. 2015;1–12. 3. Sawchyn AK, Slabaugh MA. Innovations and adaptations in trabeculectomy. 2016;27(2). 4. Koike KJ, Chang PT. Trabeculectomy: A Brief History and Review of Current Trends. Int Ophthalmol Clin. 2018;58(3):117–33. 5. Khaw PT, Chiang M, Shah P, Sii F, Lockwood A, Khalili A. Enhanced Trabeculectomy: The Moorfields Safer Surgery System. Dev Ophthalmol. 2017;59:15–35. 6. Jones E, Clarke J, Khaw PT. Recent advances in trabeculectomy technique. Curr Opin Ophthalmol. 2005;16(2):107–13. 7. Wells AP, Cordeiro MF, Bunce C. Cystic Bleb Formation and Related Complications in Limbus- versus Fornix- Based Conjunctival Flaps in Pediatric and Young Adult Trabeculectomy with Mitomycin C. 2003;6420(03):2192–7. 8. Theventhiran AB, Kim G, Yao WJ. Fornix-based versus limbal-based conjunctival trabeculectomy flaps for glaucoma. Cochrane Database Syst Rev. 2021;2021(8). 9. Cotran PR, Roh S, Mcgwin G. Randomized Comparison of 1-Site and 2-Site Phacotrabeculectomy with. 2007;447–55. 10. Freiburg U, Fr G. Limbus-based versus Fornix-based conjunctival flap in • tering surgery A r a n d o m i z e d prospective study. 1989;143(May 1988):139–43. 11. AM Khan FJ. Comparative results of limbal based versus fornix based conjunctival flaps for trabeculectomy. 1992;(2):41–3. 12. Lance c. lemon, md, dong h. shin, md, phd, chaesik kim, bsee, rick e. bendel, md, bret a. hughes, md, and mark s. juzych M. Limbus-based vs Fornix based conjunctival flap in combined glaucoma and cataract surgery with adjunctive Mitomycin c. 13. Kozobolis VP, Detorakis ET, Tsilimbaris MK, Vlachonikolis IG, Tsambarlakis IC, Pallikaris IG. Correlation Between Age-related Macular Degeneration and Pseudoexfoliation Syndrome in the Population of Crete (Greece). 1999;117(MAY):664–9. 14. Batterbury M, Wishart PK. Is high initial aqueous outflow of benefit in trabeculectomy? Eye. 1993;7(1):109–12. 15. Khaw P, Dhingra S. The moorfields safer surgery system. Middle East Afr J Ophthalmol. 2009;16(3):112. 16. Ichhpujani, Parul Bhartiya S. Releasable Sutures in Trabeculectomy. 2014;(March). 17. Gedde SJ, Schiffman JC, Feuer WJ, Herndon LW, Brandt JD, Budenz DL, et al. Treatment Outcomes in the Tube Versus Trabeculectomy (TVT) Study After Five Years of Follow-up. 2012; 18. Masoumpour MB, Nowroozzadeh MH, Razeghinejad MR. Current and Future Techniques in Wound Healing Modulation after Glaucoma Filtering Surgeries. Open Ophthalmol J. 2016;10(1):68–85. 19. Khaw PT. Advances in Glaucoma Surgery : Evolution of Antimetabolite Adjunctive Therapy. 2001;10(Suppl 1):81–4. 20. Sandra S, Amore PAD, D P, Dreyer EB. Comparative Toxicity of Mitomycin C and 5-Fluorouracil In Vitro. 1994;332–7. 21. Vinod K, Gedde SJ, Feuer WJ, Panarelli JF, Chang TC, Chen PP, et al. Practice Preferences for Glaucoma Surgery: A Survey of the American Glaucoma Society. 2018;0000000000(8):687–93. 22. Megevand S, Salmon JF, Scholtz RP, Murray ADN. The Effect of Reducing the Exposure Time of Mitomycin C in Glaucoma Filtering Surgery. 1995;84–90. Subspeciality - Glaucoma

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 53 23. Schnyder CC, Bernasconi O, Mermoud A FR. Comparative study of administration time of mitomycin C in trabeculectomy: 2.5 or 5 minutes? Klin Monatsbl Augenheilkd. 1995;307–11. 24. Manners T, Salmon JF, Barron A, Willies C, Murray ADN, Town C. Trabeculectomy with mitomycin C in the treatment of post-traumatic angle recession glaucoma. 2001;159–63. 25. Lim MC, Hom B, Watnik MR, Brandt JD, Altman AR, Paul T, et al. A Comparison of Trabeculectomy Surgery Outcomes With Mitomycin-C Applied by Intra-Tenon Injection Versus Sponge. 2020;243–56. 26. Maheshwari D, Kanduri S, Rengappa R, Kadar M. Intraoperative injection versus sponge-applied mitomycin C during trabeculectomy: One-year study. Indian J Ophthalmol. 2020;68(4):615–9. 27. Seibold LK, Sherwood MB, Kahook MY. Wound Modulation After Filtration Surgery. 2012;57(6). 28. Ray VP, Choudhari N. Rescue of failing or failed trabeculectomy blebs with slit - lamp needling and adjunctive mitomycin C in Indian eyes. 2018;71–6. 29. Skuta GL, Beeson CC, Higginbotham EJ, Lichter PR, Musch DC, Bergstrom TJ, et al. Intraoperative Mitomycin versus Postoperative 5--Fluorouracil in High--risk Glaucoma Filtering Surgery. :438–44. 30. Abraham LM, Selva D, Casson R, Leibovitch I. The Clinical Applications of Fluorouracil in Ophthalmic Practice. 2007;67(2):237– 55. 31. Crowston JG, Akbar AN, Constable PH, Occleston NL, Daniels JT, Khaw PT. Antimetabolite-Induced Apoptosis in Tenon’s Capsule Fibroblasts. 1998;(February). 32. Khaw PT, Doyle JW, Grierson I, Schultz G, Mcgorray S. Prolonged Localized Tissue Effects From 5-Minute Exposures to Fluorouracil and Mitomycin C. 2015; 33. Khaw PT, Chang L, Wong TTL, Mead A, Daniels JT, Cordeiro MF. Modulation of wound healing after glaucoma surgery. 2001;143–8. 34. Higginbotham E, Stevens RK, Musch DC, Karp KO, Lichter PR, Bergstrom T, et al. Bleb-related Endophthalmitis after Trabeculectomy with Mitomycin C. 1995;650–6. 35. Heuer DK, Ii RKP, Gressel MG, Hodapp E, Palmberg PF, Anderson DR. 5-Fluorouracil and Glaucoma Filtering Surgery II . A Pilot Study. 36. Minassian D, Tan S, Chew PTK, Ed F. The Singapore 5-Fluorouracil Trabeculectomy Study Effects on Intraocular Pressure Control and Disease. 2008;175–84. 37. Katz G, Higginbotham E, Lichter PR, Skuta GL, Musch DC, Bergstrom T, et al. Mitomycin C versus 5 , Fluorouracil in High , risk Glaucoma Filtering Surgery Extended Follow .. up. 1993;1263–9. 38. Nilforushan N. Comparison of the Success Rate of Trabeculectomy with OculusGen versus Trabeculectomy with Mitomycin C. 2016;(January 2010). 39. Senthil S, Rao HL, Babu JG, Mandal AK, Garudadri CS. Original Article Comparison of outcomes of trabeculectomy with mitomycin C vs . ologen implant in primary glaucoma. :4–8. 40. Rosentreter A, Schild AM, Jordan JF. Continuing Medical Education : A prospective randomised trial of trabeculectomy using mitomycin C vs an ologen implant in open angle glaucoma A prospective randomised trial of trabeculectomy using mitomycin C vs an ologen implant in open angle glaucoma. 2010;1449–57. 41. S Cillino, F Di Pace, G Cillino AC. Biodegradable collagen matrix implant vs mitomycin-C as an adjuvant in trabeculectomy : randomized clinical trial. 2011;1598–606. 42. Ji Q, Qi B, Liu L, Guo X, Zhong J. Efficacy and Safety of Ologen Implant Versus Mitomycin C in Primary Trabeculectomy : A Metaanalysis of Randomized. 2015;24(5). 43. Dada T, Kusumesh R, Bali SJ, Sharma S. Trabeculectomy With Combined Use of Subconjunctival Collagen Implant and Low-dose Mitomycin C. 2013;22(8):659–62. 44. Helmers G, Munteanu C, Löw U, Seitz B. Trabekulektomie mit Mitomycin C und Ologen Implantat im Vergleich zur ®- klassischen Trabekulektomie Gloria. 2023;20–6. 45. Yazdani S, Hendi K, Pakravan M, Mahdavi M, Yaseri M. Intravitreal bevacizumab for neovascular glaucoma: A randomized controlled trial. J Glaucoma. 2009;18(8):632–7. 46. Weerawat Kiddee, MD, Lachaya Orapiriyakul M, Kaneungnit Kittigoonpaisan, MD, Thawat Tantisarasart, MD, Boonchai Wangsupadilok M. Efficacy of Adjunctive Subconjunctival Bevacizumab on the Outcomes of Primary Trabeculectomy With Mitomycin C : 2015;24(8):600–6. 47. Pro MJ, Freidl KB, Neylan CJ, Sawchyn AK, Wizov SS, Moster MR. Ranibizumab Versus Mitomycin C in Primary Trabeculectomy – A Pilot Study. 2014;(November 2013):1–6. 48. Akkan JU, Cilsim S. Role of Subconjunctival Bevacizumab as an Adjuvant to Primary Trabeculectomy : A Prospective Randomized 1-Year Follow-up Study. 2015;24(1):1–8. 49. Muhsen, Sana, Compan J, Lai T, Kranemann C, Birt C. Postoperative adjunctive bevacizumab versus placebo in primary trabeculectomy surgery for glaucoma. 2019;12(10):1567–74. 50. Chan, Jessica E Netland PA. EX-PRESS Glaucoma Filtration Device : efficacy, safety, and predictability. 2015;381–8. Dr. Anugya Sharma, MBBS, DNB Department of Glaucoma, Shroff’s Charity Eye Hospital. Corresponding Author: Subspeciality - Glaucoma

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 54 Optic Disc Pit Maculopathy Jatinder Singh Bhalla, MBBS, MS, DNB, MNAMS, Sadiqua Khatoon, MBBS, DO, Ridhima Sakhuja, MBBS, MS, DNB, FPOS, Yogesh Kumar, MBBS, Neha Yadav, MBBS, Ashish Kumar Sain, MBBS, DO, Karuna, MBBS, DO, DNB, Tarun Patidar, MBBS Department of Ophthalmology, DDU Hospital, Hari Nagar, New Delhi. Optic disc pit (ODP) is a rare, anomalous cavitation of the optic nerve.[1] First described by Weithe,[1] ODPs are mostly congenital. Acquired ODPs have also been reported secondary to glaucoma and myopia.[2] ODP commonly presents at the inferotemporal segment of the disc, but may also be observed elsewhere, including the central segment.[1] They are often related to strands of attached and condensed vitreous collagen at the retinal surface.[3,4] ODPs tend to be solitary, but two or three pits occurring together have also been reported.[5] Epidemiology The prevalence of ODP is approximately 1:11,000.[6] The majority of cases are thought to be congenital (CODPs); however, acquired ODPs (AODPs) may occur secondary to glaucoma or myopia. AODPs occur twice as frequently in women. Although ODPs are most often unilateral, they are bilateral in approximately 15% of cases overall. However AODP are bilateral in 21% to 48% of cases.[6] Optic disc pit maculopathy (ODP-M) occurs in approximately 25% to 75% of ODP patients.[7] This complication manifests as serous retinal detachment, cystic changes, or degenerative pigment changes of the macula. Usually single optic disc pits are reported, Double optic disc pit are very rare. Till date, only 12 cases of double ODP have been reported in the literature. Out of these twelve cases.[8-16] 5 eyes had pits in opposite segments of the disc i.e. nasal and temporal. Rest 7 eyes had both the pits in the single segment i.e. temporal. Out of the 5 eyes with nasal pit, only two eyes had tell-tale retinal signs.[8,10,11,14] Etiology ODPs are thought to develop from anomalies in the neuroectodermal folds of the primitive papillae, leading to an abnormal communication between the pit and the subarachnoid space. Risk Factors Some rare diseases are associated with an increased risk of ODP. These include: • Basal encephalocele • Aicardi syndrome • Alagille syndrome • Bilateral renal hypoplasia • Midline neurodevelopmental defects Pathophysiology Histologically, an ODP appears as a herniation of dysplastic retinal tissue through a defect in the lamina cribrosa, extending posteriorly to the subarachnoid space. This defect may lead to intraretinal and subretinal fluid in the macula,[17] although the source of fluid and the mechanism of fluid migration are not fully understood. It characteristically occurs during the third or fourth decade of life, but in many cases can occur much earlier. Sources of fluid in optic disc pit maculopathy It has been postulated that cerebrospinal fluid can pass from the subarachnoid space through the ODP and eventually enter the intra- and sub-retinal spaces.[18,19] Optical coherence tomography (OCT)–based studies have revealed a direct communication between the subarachnoid space and the subretinal space. Moreover, it has been observed that after pars plana vitrectomy (PPV) and intravitreal gas injection, gas bubbles percolate out of an optic nerve sheath window. This indicates that there is a continuity between the optic nerve subarachnoid space and the posterior vitreous. The concept of leaking blood vessels at the ODP has also been suggested,[20] and was based on the fact that fluorescein angiography showed late hyperfluorescence and segments of macular elevation in eyes with ODP-M. However, this feature is not present in all patients with ODP-M. Fluid in ODP-M may also derive from the choroid, via Bruch membrane and peripapillary atrophy,[21] but this source is quite unlikely, as subretinal fluid is not common in other pathologies that also cause significant chorioretinal atrophy. Clinical Presentation During routine examination in asymptomatic individuals, ODP and ODP-M may be detected incidentally. Patients with ODP are most often asymptomatic, whereas a majority of patients with ODP-M complain of recent gradual decrease of vision. The drop in VA is consistent with the development of serous macular detachment. Depending on the degree of maculopathy (ie, extent of schisis, sensory detachment, and duration), VA can vary from Snellen 20/25 to counting fingers.It has been reported that a small number of patients have mentioned impairment of vision when bending over. Visual fields and colour vision may also be impaired. Diagnostics Approach Fundus Findings Typically, ODP presents as a round or oval excavation near the margin of the optic disc that appears gray, white, or black and occupies 1/8th to 1/4th of the disc. ODPs do not obscure the optic disc margin or physiological optic cup which differentiates them optic disc pits from optic disc coloboma.[1] Subspeciality - Retina

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 55 Optical Coherence Tomography OCT imaging of an ODP will show a defect in the lamina cribrosa with herniation of nerve tissue into the pit. If ODP-M is present, OCT will demonstrate both intraretinal and subretinal fluid collections. The pattern specific to ODP-M is the dual morphology of serous retinal detachment with a schisis cavity and a coexisting detachment of the outer layer of the retinal pigment epithelium.[6] Imamura et al used spectral-domain OCT Fundus Autoflorescence (FAF) FAF shows hyperfluorescence in a granular pattern, as well as subretinal precipitates. Also, areas of serous retinal detachment Figure 1: Colour fundus image showing (a) Single optic disc pit in temporal aspect of the disc (black arrow) with serous retinal detachment (dotted circle). (b) Double optic disc pit, grey in colour, one at inferotemporal aspect of the disc another one at temporal aspect of disc with large serous retinal detachmen (dotted circle). Figure 2: Optical coherence tomography image of line scan of macula-red arrow showing retinoschisis, blue arrow showing pigment epithelial detachment, yellow arrow showing subretinal fluid accumulation. and found that the fluid was mainly accumulated in the outer nuclear layer (94%), followed by the inner nuclear layer (81%), the ganglion cell layer (44%), and the sub-internal limiting membrane (13%). Furthermore, 69% of eyes were diagnosed with a neurosensory detachment, but only 1 of them had an outer layer hole, and 81% of these eyes had intraretinal fluid in more than 1 layer of the sensory retina.[22] and inner retinal schisis appear hypofluorescent, but they will become bright after successful vitrectomy and retinal reattachment. Subspeciality - Retina

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 56 Visual Field Defects Two different mechanisms can lead to visual field defects in patients with ODP. The first is probably associated with the displacement of nerve fibers by the ODP which usually causes an arcuate scotoma. However, all types of visual field defects Figure 3: Fundus autofluorescence (left) showing hypoautofluorescence in the area of serous retinal detachment, (right) hupoautofluorescence nasally in the region corresponding to RPE degeneration, bordered by hyper autofluorescence ring. Figure 4: Visual field analysis shows arcuate scotoma (red arrow) in a case of Optic disc pit maculopathy. (paracentral scotomas, enlarged blind spots, nasal or temporal steps, altitudinal defects, or generalized depression) can be observed.[3] The second mechanism is likely to be caused by a serous retinal detachment, which typically leads to either a central scotoma or other central visual field defects. Subspeciality - Retina

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 57 Differential Diagnosis • Optic nerve hypoplasia • Megalopapilla • Optic disc coloboma • Morning glory anomaly • Glaucomatous disc Optic Nerve Hypoplasia Megalopapilla Morning Glory Anomaly Optic Nerve Coloboma It is an abnormally small optic nerve head It presents as an enlarged optic nerve head diameter exceeding 2.1 mm with an increased cup-to-disc ratio with horizontally elongated cup. It appears as a funnel-shaped excavation, an enlarged optic nerve head, and an increased number of disc vessels. Characterized by an inferior excavation in optic nerve head associated with iris and choroidal coloboma. Management Macular edema and serous macular detachment secondary to ODP-M were originally treated conservatively. However, because observation alone is often associated with poor visual outcomes, a more aggressive surgical approach is appropriate in some cases. PPV and adjunctive therapies: PPV is the most widely accepted treatment for serous macular detachment associated with ODP-M. Adjuncts to PPV include internal limiting membrane peeling, laser, and gas or silicone tamponade. Although laser photocoagulation is sometimes used as monotherapy to treat serous macular detachment in ODP-M, laser alone has been shown to have worse outcomes compared with vitrectomy. It is now more commonly used as an adjunct to vitrectomy with gas tamponade. Intravitreal gas injection with perfluoro ethane, sulfur hexafluoride, or perfluoropropane is performed to attempt reattachment of the macula in cases of ODP-related detachment. This technique is often used in conjunction with PPV and laser.[23] Macular buckling: This surgery involves fixation of a sponge implant to the posterior segment of the globe to produce a buckling effect under the macula. Although it is associated with good outcomes in the management of ODP-related macular detachment, it is a technically difficult surgery with a steep learning curve. Thus, it is not utilized as often as vitrectomy. Newer modalities of management of optic disc pit • Autologous platelet injection over the ODP after PPV has been successful in treating a patient with persistent ODPrelated macular detachment.[24] • Vitrectomy with radial inner retinal partial-thickness fenestration is a newer surgical technique that has been shown to completely resolve subfoveal fluid in 94% of eyes.[25] • Sealing of ODPs with autologous scleral flaps has been reported to be effective in inducing retinal reattachment and improving VA.[7] • PPV and temporal-side single radial optic neurotomy is thought to create a barrier to fluid passage by creating scar tissue and is associated with fluid resolution in 86% of eyes.[26] • Foveal-sparing internal limiting membrane peeling (FSIP) technique with inverted ILM flap tucking with gas tamponade.[27] Figure 5: optical coherence tomography image of macula (left) preoperative status of macula with serous retinal detachment (SRD,847μ) and intraretinal fluid accumulation (right) 30 days postoperatively(PPV with ILM peeling with Fluid air exchange and gas tamponade) showing reduction of SRD (497μ) and copmpletely resolved intraretinal fluid. Subspeciality - Retina

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 58 Figure 6: Optical coherence tomography images of line scan through disc showing (a) preoperative status of optic disc showing two pits, one at inferotemporal aspect of the disc (solid arrow) and the other one is inferonasal aspect of the disc (arrowhead) and communication between disc and retinal layers (thin arrow) (b) preoperative status of optic disc showing communication between pit and subretinal space (c) postoperative status showing closure of communication.[7] References 1. Georgalas I, Ladas I, Georgopoulos G, et al. Optic disc pit: a review. Graefes Arch Clin Exp Ophthalmol. 2011;249:1113–1122. 2. Healey PR, Mitchell P. The prevalence of optic disc pits and their relationship to glaucoma. J Glaucoma. 2008;17:11–14. 3. Brown GC, Shields JA, Goldberg RE. Congenital pits of the optic nerve head: II. Clinical studies in humans. Ophthalmology. 1980;87:51–65. 4. Kranenburg EW. Crater-like holes in the optic disc and central serous retinopathy. Arch Ophthalmol. 1960;64:912–924. 5. Irvine AR, Crawford JB, Sullivan JH. The pathogenesis of retinal detachment with morning glory disc and optic pit. Trans Am Ophthalmol Soc. 1986;84:280–292. 6. Uzel MM, Karacorlu M. Optic disk pits and optic disk pit maculopathy: A review. Surv Ophthalmol 2019;64(5):595-607. 7. Babu N, Baliga G, Kohli P, Ramasamy K. Management of double optic disc pit complicated by maculopathy. Indian J Ophthalmol 2020;68:663 5. 8. De Laey JJ, Goes F, Box D. Double optic pit with wedge shaped choroidal dystrophy. Int Ophthalmol 1979;1:171 4. 9. Jonas JB, Naumann GO. Pits of the optic papilla in large optic nerve papillae. Papillometric characteristics in 15 eyes. Klin Monbl Augenheilkd 1987; 191:287 91. 10. Silva NA, Bedran MF, Silva FA, Rocha GM. Unilateral double optic disc pit: Case report. Arq Bras Oftalmol 2010;73:459 61. 11. Gregory Roberts EM, Mateo C, Corcóstegui B, Schiff WM, Chang LK, Quiroz Mercado H, et al. Optic disk pit morphology and retinal detachment: Optical coherence tomography with intraoperative correlation. Retina 2013;33;363 70. 12. Choudhry N. Double optic pit maculopathy. Ophthalmic Surg Lasers Imaging Retina 2015; 46:284 6. 13. Ali Z, Abdul Nabi M. A rare case of symptomatic double optic disc pit without maculopathy. Case Rep Ophthalmol Med 2016;2016:2560568. 14. Koulouri I, Gaier ED, Eliott D, Vavvas DG. Double optic disc pit with glial plugs imaged by wide field optical coherence tomography. Ophthalmic Surg Lasers Imaging Retina 2018; 49:52 4. Subspeciality - Retina

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 59 15. Pozza E, Postelmans L. Double optic pit and associated maculopathy. J Fr Ophtalmol 2018; 41:884 5. 16. Boese EA, Huang D, Tehrani S. Unilateral double optic nerve head pits. Ophthalmology 2018;125:458. 17. Ohno-Matsui K, Hirakata A, Inoue M, et al. Evaluation of congenital optic disc pits and optic disc colobomas by swept-source optical coherence tomography. Invest Ophthalmol Vis Sci. 2013;54:7769– 7778. 18. Krivoy D, Gentile R, Liebmann JM, et al. Imaging congenital optic disc pits and associated maculopathy using optical coherence tomography. Arch Ophthalmol. 1996;114:165–170. 19. Rutledge BK, Puliafito CA, Duker JS, et al. Optical coherence tomography of macular lesions associated with optic nerve head pits. Ophthalmology. 1996;103:1047–1053. 20. Gass JD. Serous detachment of the macula. Secondary to congenital pit of the optic nervehead. Am J Ophthalmol. 1969;67:821–841. 21. Wise GN, Dollery CT, Henkind P. Pattern and location of retinal vessels. In: The Retinal Circulation. New York: Harper and Row; 1971: 19–31. 22. Imamura Y, Zweifel SA, Fujiwara T, et al. High-resolution optical coherence tomography findings in optic pit maculopathy. Retina. 2010;30: 1104–1112. 44. 23. Chatziralli I, Theodossiadis G, Panagiotidis D, et al. Long-term changes of macular thickness after pars plana vitrectomy in optic disc pit maculopathy: A spectral-domain optical coherence tomography study. Semin Ophthalmol. 2017;32:302–308. 24. Rosenthal G, Bartz-Schmidt KU, Walter P, et al. Autologous platelet treatment for optic disc pit associated with persistent macular detachment. Graefes Arch Clin Exp Ophthalmol. 1998;236:151–153. 25. Ooto S, Mittra RA, Ridley ME, et al. Vitrectomy with inner retinal fenestration for optic disc pit maculopathy. Ophthalmology. 2014;121: 1727–1733. 26. Karacorlu SA, Karacorlu M, Ozdemir H, et al. Optical coherence tomography in optic pit maculopathy. Int Ophthalmol. 2007;27:293– 297. 27. Kumar K, Bhattacharya D. Unilateral double optic nerve head pits with foveo-schisis detachment treated by modified internal limiting membrane peeling technique. Indian J Ophthalmol. 2022 Mar;70(3):1054-1057. Dr. Sadiqua Khatoon, MBBS, DO Department of Ophthalmology, DDU, Harinagar, New Delhi. Corresponding Author: Subspeciality - Retina

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 60 Capillary Hemangioblastoma in Von-Hippel-Lindau Syndrome Smita Kapoor, MS, DNB, MNAMS, FAICO, Apoorv Grover, DNB, MNAMS, FICO, FAICO, FRCOph Vision Eye Centres, New Delhi. Introduction Von-Hippel-Lindau syndrome is a form of phacomatoses in which patients develop benign and malignant tumors in multiple organs and the treatment is usually surgical. Diagnosis of isolated cases of VHL is often delayed as compared to familial cases. A timely diagnosis is required to extend genetic counselling to other family members as well. Case An 18-year-old male presented with acute onset diminution of vision in the left eye for 6 months. He had no ocular complaints in the past. However, two of his older siblings had a history of poor vision. Both siblings had undergone surgery for retinal detachment. One sibling had a renal tumor while the other had a brain tumor. On examination, his visual acuity was (OD) 6/6, N6 and (OS) 6/60, N24. His anterior segment examination was normal. Fundus examination revealed exudates and edema at the macula with tortuous vessels feeding the capillary hemangioblastoma in the periphery in the left eye while the fundus in the right eye was normal. A Spectral domain optical coherence tomogram was performed and that revealed macular edema in the left eye. He was treated with Anti-VEGF injections following which the edema resolved and his vision improved to 6/12, N9 (OS) and has been stable since then. He tested positive for the VHL gene along with his other 2 siblings. His abdominal ultrasound and brain MRI were normal. Comment VHL is an autosomal dominant condition characterized by the development of hemangioblastomas of the retina and central nervous system (cerebellum, brainstem, spinal cord), clear cell renal carcinoma, and pheochromocytoma.[1] The VHL tumor suppressor gene is located on chromosome 3p25- 26 and germline mutations lead to inactivation of the VHL protein. Angiogenesis is seen in VHL due to the overproduction of VEGF. Ocular manifestations are seen in over half of the patients and retinal capillary hemangioblastoma is the most frequent and earliest manifestation. The mean age of onset is 21 years, which is less than the onset of other tumors. 58% of the tumors are unilateral and often seen in the retinal periphery. Initially, only a red-grey dot becomes visible but as the tumor Abstract: Von Hippel Lindau syndrome is a form of phacomatoses that presents with ocular and systemic manifestations. It is inherited in an autosomal dominant manner. Here we report the case of an 18-year-old male who presented with a capillary hemangioblatoma and was diagnosed with VHL. grows, tortuous feeder vessels, retinal exudates, and retinal edema develop.[2] Juxtapapillary lesions may not grow for long periods of time. Fundus fluorescein angiography usually reveals small superficial vascular lesions close to a retinal vein. If left untreated, hemangioblastomas usually enlarge, therefore early diagnosis and treatment is important to prevent visionthreatening complications. Exudative or tractional retinal detachment may develop in long standing cases which can later lead to the development of neovascularization of the iris and secondary glaucoma. Severe visual deficits occur in 5-7% of the patients.[3] The visual outcomes are worse if the age of onset of ocular disease is early, both the eyes are involved and there is missense mutation in VHL. A multidisciplinary approach is required in the management of VHL. With the advent of genetic testing, early diagnosis can be made. Treatment of the hemangioblastoma includes photocoagulation/cryotherapy, intravitreal anti-VEGF injections, and surgical resections to prevent the development of exudative or tractional retinal detachment.[4] All VHL patients require lifetime screening of retinal tumors, audiology assessments, abdominal ultrasounds and MRI scans to rule out abdominal and brain/spine tumors.[5] Figure 1: (OS) Exudates and edema at the macula with tortuous vessels feeding the capillary hemangioblastoma in the periphery Subspeciality - Retina

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 61 References 1. Von Hippel-Lindau disease: a clinical and scientific review. Maher ER, Neumann HP, Richard S. Eur J Hum Genet. 2011;19:617–623. 2. Ruppert MD, Gavin M, Mitchell KT, Peiris AN. Ocular Manifestations of von Hippel-Lindau Disease. Cureus. 2019 Aug 4;11(8):e5319. doi: 10.7759/cureus.5319. PMID: 31588386; PMCID: PMC6776162. 3. Varshney N, Kebede AA, Owusu-Dapaah H, Lather J, Kaushik M, Bhullar JS. A Review of Von Hippel-Lindau Syndrome. J Kidney Cancer VHL. 2017 Aug 2;4(3):20-29. doi: 10.15586/jkcvhl.2017.88. PMID: 28785532; PMCID: PMC5541202. 4. Wiley HE, Krivosic V, Gaudric A, Gorin MB, Shields C, Shields J, Aronow ME, Chew EY. MANAGEMENT OF RETINAL HEMANGIOBLASTOMA IN VON HIPPEL-LINDAU DISEASE. Retina. 2019 Dec;39(12):2254-2263. doi: 10.1097/ IAE.0000000000002572. PMID: 31259811; PMCID: PMC6878154. 5. Singh AD, Shields JA, Shields CL. Solitary Retinal Capillary Hemangioma: Hereditary (von Hippel-Lindau Disease) or Nonhereditary? Arch Ophthalmol. 2001;119(2):232–234. doi:10- 1001/pubs.Ophthalmol.-ISSN-0003-9950-119-2-ecs90255. Dr. Smita Kapoor, MS, DNB, MNAMS, FAICO Consultant Cataract, Strabismus, Paediatric & Neuro-Ophthalmology Services Vision Eye Centres, New Delhi. Corresponding Author: Subspeciality - Retina

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 62 Femtosecond Laser: Applications in Modern Refractive Surgery Kumar Doctor, MD, Shivani P Pattnaik, MS Doctor Eye Institute, Mumbai. Introduction The femtosecond laser has become an indispensable and vastly utilised technology for refractive surgeons. Advanced models of machinery and improvised laser software have given it a sharper clinical edge and good safety outcomes. This review aims to outline the current surgical applications of the femtosecond laser in corneal refractive surgery. The Beginning In the early 1980s, Mourou and Strickland introduced the concept of chirped pulse amplification (CPA), a method that amplified short laser pulses to ultra-high peak powers. This seminal development paved the way for the birth of femtolaser technology.[1] The laser can be delivered in a specified pattern and intrastromal depth that is set pre-operatively via computer software. As the energy can be focused at a desired depth, even through mild opacities, creation of numerous adjacent cavitation bubbles in a specified pattern provides a precise and powerful tool for tissue dissection. Mechanics The pulse duration of the femtosecond laser is in the 10-15 second range. With a wavelength of approximately 1053 nanometers, femtolaser technology produces ultrafast laser pulses that are capable of operating at the femtosecond scale, or one quadrillionth of a second and is not absorbed by optically transparent tissues. The area of focus can be preset within the cornea and the energy can be dialled to a threshold to generate plasma. This further generates a shock wave of rapidly expanding cloud of free electrons and ionized molecules and further results in disruption of the target tissue. In this process plasma state consisting of free electrons and ions is generated that displaces the surrounding material by expanding at high velocity. This initial displacement spreads through the tissue as shockwave despite slowing of the plasma expansion (Figure-1). As a cavitation gas bubble is formed by the vaporised tissue in the focal volume of laser beam, the temperature of rapidly expanding plasma quickly decreases. The cavitation bubble, consists of carbon dioxide (CO2), nitrogen (N2) and water (H2O), diffuses out of the tissue. The ablation is non-thermal due to extremely short interaction time. It uses an infrared (1053nm) scanning pulse with an accuracy of 1 micron to cut a pattern in the corneal stroma, creating precise lamellar flaps. As a cavitation gas bubble is formed by the vaporised tissue in the focal volume of laser beam, the temperature of rapidly Figure 1: Femtosecond Laser photo disruption. Advent in Refractive Surgery Since FDA approval of an ultrafast laser in 2000, the femtosecond laser has revolutionized the creation of flaps for laser assisted laser in situ kertomileusis (LASIK).[2] Clinical Applications Femtosecond technology, along with its approval for LASIK, was swiftly picked up for various other corneal and refractive procedures such as: 1. Customised creation of a channel for implantation of intrastromal corneal ring segments (ICRS), for both allogenic and inert synthetic implants. With the help of the advanced Femto technology, donor cornea can also be customized to any width, length and size. 2. Limbal relaxing incisions (LRI) expanding plasma quickly decreases. The cavitation bubble, consists of carbon dioxide (CO2), nitrogen (N2) and water (H2O), diffuses out of the tissue. The ablation is non-thermal due to extremely short interaction time. It uses an infrared (1053nm) scanning pulse with an accuracy of 1 micron to cut a pattern in the corneal stroma, creating precise lamellar flaps. Subspeciality - Refractive Surgery

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 63 3. Small-incision lenticule extraction (SMILE)/Corneal Lenticule Extraction for Advanced Refractive correction (CLEAR) 4. Intrastromal presbyopia correction (INTRACOR) 5. Anterior and posterior lamellar keratoplasty and cutting of donor buttons Currently Available Femtosecond Lasers There are a number of US Food and Drug Administration (FDA) approved femtosecond laser platforms for use in corneal refractive surgery. Namely the, Victus (Bausch and Lomb Surgical), ELITA (Johnson and Johnson), ATOS (Schwind), IntraLase FS laser (Abbott Medical Optics Inc., Santa Ana, California, USA)the WaveLight FS laser (Alcon Laboratories Inc., Fort Worth, Texas, USA) the VisuMax (Carl Zeiss, Meditec AG, Jena, Germany) and Femto LDV Z8 (Zeimer Ophthalmic Systems, Port, Switzerland). Detailed comparison of the laser systems is shown in the table, (Table-1). PARAMETER IntraLase FS Tecnolas/Femtec Femto LDV Wavelight VisuMax Pattern Raster Spiral Segmental Raster Spiral Applanation Planar Curved Planar Planar Curved Mobility No No Yes No No Wavelength 1053 nm 1053 nm 1045 nm 1045 nm 1043 nm Type of Laser Amplifier Amplifier Oscillator OscillatorAmplifier Fibre-optic Amplifier Table 1: Comparison of Femtosecond machines. Limitations of Femto Application in Lenticular Extraction 1. Corneal wavefront guided or ocular wavefront guided laser surgery is not possible. 2. Hyperopia and hyperopic astigmatism is yet not possible. 3. Cyclotorsion compensation is possible in new generation Femto lasers but multiple adjustments can be made and techniques are innovated to make the same possible. Advantages in Femtosecond Laser Assisted Corneal Flap Creation In femtosecond LASIK, the femtolaser is used to create a flap in the cornea with unparalleled precision. By leveraging the accuracy of femtolaser technology, ophthalmologists are able to correct refractive errors such as myopia, hyperopia, and astigmatism more effectively and safely than with a microkeratome Advantages of bladeless femtosecond assisted LASIK (FS- LASIK) over conventional microkeratome assisted LASIK (MK-LASIK) include: 1. Reduced dry eye cases. 2. Minimise risk of button hole flap or free cap formation and gentler approach. 3. The flap diameter to hinge ratio is consistently the same, which is why when the flap is reposited, it falls back uniformly. 4. The size of the hinge is consistent, unlike variable hinge size in microkeratomes. 5. The side cut can be made from 70 to 150 degrees, therefore the apposition of the side cut is far superior than the microkeratome. 6. More uniform flap thickness resulting in uniform flap weight resulting in perfect placement of the flap. 7. Superior consistency in flap diameter, thickness accuracy and reproducibility. 8. Thinnest flaps of 90μm or even thinner planar flap in comparison to the meniscus flap (thinner centrally and thicker peripherally) created with the microkeratome. 9. Reduce clinically significant epithelial ingrowth due to better apposition of angulated flaps. 10. The ability to resume a lamellar flap after loss of suction or technical interruptions, and even when performing a secondary flap underneath a primary of substandard quality with little risk of serious repercussions as the new machines have a built in OCT, so the original flap thickness can be analysed and re-cut. 11. Biomechanical tissue stability i.e. the ability to cut ultra thin flaps with no effects on stromal architecture. 12. Smaller and tightly packed cavitation bubbles to facilitate practically resistance-free corneal stromal bridges, predictable flaps with smooth interfaces, and advanced software algorithms for the creation of elliptical flaps or everted edges for mechanical stability. 13. Always a well centered flap on the pupil as the trajectory of the Femtolaser can be moved during the vacuum build up. 14. Some Femtolasers can create an elliptical flap for high cylindrical powers, which is not possible in microkeratomes. Disadvantages and Unique Complications Some significant complications unique to FS laser are: 1. Opaque bubble layer (OBL): Gas bubbles that accumulate in the flap interface during FS laser treatment, may dissect into Subspeciality - Refractive Surgery

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 64 the deep stromal bed and interfere with the laser eye tracker device. The bubbles may also seep into the anterior chamber through the trabecular meshwork. Can be prevented by use of the raster or centripetal patterns and peripheral gutters while selecting the cut. 2. Ocular surface inflammatory mediators and microscopic tissue injury and may cause lamellar keratitis. Lamellar keratitis after Fs LASIK usually resolves with nil sequelae. 3. Transient light sensitivity syndrome (TLSS): Patients present with extreme photophobia due to inflammatory sequelae and good visual acuity with no clinical findings on exam. Requires aggressive topical steroids for weeks then resolves 4. Cost, skill and learning curve: A constant debate and an uphill climb for those who wish to diversify. Conclusion Femtosecond laser creates corneal flaps that have greater safety and thickness predictability. The flaps cut are planar and uniformly thick compared to meniscus-shaped flaps in mechanical microkeratome. In addition, the flap adherence is stronger and less influenced by trauma; it shows better contrast sensitivity, less incidence of dry eyes and lesser rate of epithelial ingrowth. Moreover, femtosecond reduces the likelihood of short flaps, epithelial abrasions, button-hole perforations, and blade marks. With newer femtolasers and the technique of small incision lenticular extraction, with a cap of 130 microns is widely documented to have a lesser incidence of dry eyes and no risk of flap complications like striae or folds. This will truly stand the test of time. Though it is associated with more chances of developing photosensitivity, diffuse keratitis etc., given the choice of modern steroid eye drops exceptional results with femto-LASIK will give a tough time to its rivals. The coming years of research will show whether the flapless lenticule technology will overtake flap LASIK in refractive surgery. References 1. Soong HK, Malta JB. Femtosecond lasers in ophthalmology. Am J Ophthalmol. 2009;147:189–97. 2. Binder PS. One thousand consecutive IntraLase laser in situ keratomileusis flaps. J Cataract Refract Surg 2006;32:962-9. Dr. Kumar Doctor, MD Doctor Eye Institute, Mumbai. Corresponding Author: Subspeciality - Refractive Surgery

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 65 Myopia and Pregnancy: Understanding The Relationship, Effects and Care Preeti Sharma, Ph.D. (Scholar) Department of Pediatric Ophthalmology, Strabismus and Neuro-ophthalmology, Dr. Shroff’s Charity Eye Hospital, New Delhi, India. Introduction Pregnancy is a transformative phase in a woman’s life, accompanied by various physiological changes. While the focus is often on the well-being of the growing fetus, it’s essential not to overlook the potential impact on maternal health, including visual changes. For women with myopia, the hormonal and physiological alterations during pregnancy can result in temporary or long-term fluctuations in visual acuity. The metabolic and hormonal changes that occur during pregnancy can disrupt the normal functioning of the eyes, leading to myopia, which is a common complaint among expectant women. The development of myopia during pregnancy can be attributed to both physiological changes that naturally occur during this period and the exacerbation of pre-existing medical conditions.[1-2] While most cases of myopic changes during pregnancy are temporary and resolve after childbirth, there is a possibility of permanent complications that can adversely affect the overall health of women. It is important to recognize and address these visual changes to ensure the well-being of pregnant women and mitigate any potential long-term consequences.[1,3] This article aims to provide valuable insights into managing myopia during pregnancy, understanding pregnancy-related visual changes, and offering practical tips for maintaining optimal eye health. Numerous studies conducted worldwide have consistently shown an increased prevalence of myopia during pregnancy, primarily attributed to metabolic and hormonal changes.[4-8] Throughout pregnancy, elevated levels of estrogen and progesterone result in fluid retention in the cornea, leading to corneal edema, increased thickness and curvature, and subsequent changes in refractive power, ultimately resulting in myopia.[4,10,11,12,5,8] These hormonal fluctuations and associated physiological changes have been extensively documented as key factors contributing to the development of myopia during pregnancy. Furthermore, myopia during pregnancy may also be associated with pre-existing neuro-ophthalmic conditions or other underlying conditions that are exacerbated by pregnancy. Understanding the mechanisms behind these changes is vital for providing appropriate management and care for pregnant women experiencing myopia.[5] Understanding Pregnancy-Related Visual Changes During pregnancy, hormonal shifts, fluid retention, and changes in blood volume can influence the refractive properties of the eye. These changes may lead to temporary shifts in vision for women with myopia, causing either an improvement or a worsening of their refractive error. Additionally, pregnant women may experience dry eyes, blurred vision, or difficulty focusing due to hormonal fluctuations and changes in tear production. It’s crucial to be aware of these potential visual changes to ensure timely management. The exact causes of myopia during pregnancy are still being investigated. However, hormonal fluctuations and physiological changes appear to play a role. Pregnancy hormones, such as estrogen and progesterone, can affect the shape of the cornea and increase the thickness of the lens, potentially leading to temporary changes in visual acuity. Additionally, fluid retention and changes in blood volume during pregnancy can cause slight changes in the refractive properties of the eye. Impact on Visual Health For most women, myopia during pregnancy is a temporary condition that resolves after childbirth. However, for some, the changes in visual acuity may persist or worsen. Pregnant women with pre-existing myopia may experience an increase in their prescription, requiring adjustments to their eyeglasses or contact lenses. Furthermore, myopia progression during pregnancy can increase the risk of associated complications, such as retinal detachment or glaucoma. Regular consultations with eye care professionals, such as ophthalmologists or optometrists, are essential during pregnancy. These specialists can monitor changes in visual acuity, evaluate the progression of myopia, and provide appropriate recommendations for managing any vision-related concerns. It’s important to inform healthcare providers about pregnancy to ensure safe and suitable treatment options. Management and Precautions Managing myopia during pregnancy involves a combination of regular eye examinations and taking certain precautions. Here are some essential measures: Regular Eye Examinations: Pregnant women with myopia should undergo regular eye examinations to monitor any changes in their visual acuity. These examinations can help detect early signs of myopia progression or identify any underlying eye conditions that may require immediate attention. Lifestyle Modifications: Making certain lifestyle modifications can contribute to maintaining optimal eye health during pregnancy. Here are some helpful tips: 1. Balanced Nutrition: Follow a well-rounded diet rich in Subspeciality - Systemic Diseases

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 66 nutrients beneficial for eye health, such as vitamin A, C, and E, omega-3 fatty acids, and antioxidants. Include foods like leafy greens, colorful fruits, fish, nuts, and seeds. 2. Adequate Hydration: Stay hydrated throughout the day, as it can help alleviate dry eyes and support overall eye comfort. 3. Eye Rest and Breaks: Take regular breaks from prolonged activities that require focused vision, such as working on screens or reading. Practice the 20-20-20 rule- every 20 minutes, look at something 20 feet away for 20 seconds. 4. Eye Protection: Shield your eyes from excessive sunlight and harmful ultraviolet (UV) rays by wearing sunglasses with UV protection. This is particularly important due to increased sensitivity to sunlight during pregnancy. 5. Maintain Good Hygiene: Follow proper eye hygiene practices, such as washing hands before touching your eyes or applying eye drops, to prevent potential infections. 6. Avoid Eye Strain: Ensure adequate lighting when engaging in activities that require visual concentration. Position reading materials or screens at a comfortable distance to reduce eye strain. Vision Correction Options: Depending on the severity of myopia, vision correction options like glasses or contact lenses may be prescribed. It’s important to consult with an ophthalmologist or optometrist to determine the best solution during pregnancy. Safety Precautions: Pregnancy is a time when certain medications and procedures may be contraindicated. Inform your healthcare provider about your pregnancy before starting any new medications or undergoing any surgical procedures related to myopia. Conclusion Prioritizing eye care during pregnancy is crucial for expectant mothers to maintain good eye health and manage myopia effectively. While myopia during pregnancy may be temporary for many women, it is essential to closely monitor any changes in visual acuity and take proactive measures. Regular consultations with eye care professionals, along with lifestyle modifications and appropriate vision correction options, form a comprehensive approach to managing myopia during this transformative phase of life. By understanding the potential visual changes associated with pregnancy and implementing practical strategies, women can ensure their visual well-being and contribute to their overall health and the well-being of their baby. References 1. Nkiru ZN, Obiekwe O, Lilian O, Daniel CN, Uchenna IN, Rich U. Visual acuity and refractive changes among pregnant women in Enugu, Southeast Nigeria. J Family Med Prim Care. (2018) 7(5):1037. 10.4103/jfmpc.jfmpc_335_17 [PMC free article] [PubMed] [CrossRef] [Google Scholar]. 2. Mehdizadehkashi K, Chaichian S, Mehdizadehkashi A, Jafarzadepour E, Tamannaie Z, Moazzami B, et al. Visual acuity changes during pregnancy and postpartum: a cross-sectional study in Iran. J Pregnancy. (2014) 2014:675792. 10.1155/2014/675792 [PMC free article] [PubMed] [CrossRef] [Google Scholar]. 3. Rezai S, LoBue S, LoBue T, Giovane R, Carney M. Ophthalmic complications and ocular changes in pregnancy—A review. Obstet Gynecol Int J. (2016) 4(1):00093. 10.15406/ogij.2016.04.00097 [CrossRef] [Google Scholar]. 4. Physiological changes in pregnancy Priya Soma-Pillay, MB ChB, MMed (O et G) Pret, FCOG, Cert (Maternal and Foetal Med) SA, Nelson-Piercy Catherine, MA, FRCP, FRCOG, Heli Tolppanen, MD, Alexandre Mebazaa, MD, Heli Tolppanen, MD, and Alexandre Mebazaa, MD Cardiovasc J Afr. 2016 Mar-Apr; 27(2): 89–94. doi: 10.5830/CVJA-2016-021. 5. Mehdizadehkashi K, Chaichian S, Mehdizadehkashi A, Jafarzadepour E, Tamannaie Z, Moazzami B, et al. Visual acuity changes during pregnancy and postpartum: a cross-sectional study in Iran. J Pregnancy. (2014) 2014:675792. 10.1155/2014/675792 [PMC free article] [PubMed] [CrossRef] [Google Scholar]. 6. Mackensen F, Paulus WE, Max R, Ness T. Ocular changes during pregnancy. Deutsches Ärzteblatt Int. (2014) 111(33–34):567. 10.3238/arztebl.2014.0567 [PMC free article] [PubMed] [CrossRef] [Google Scholar]. 7. Sharma S, Rekha W, Sharma T, Downey G. Refractive issues in pregnancy. Aust N Z J Obstet Gynaecol. (2006) 46(3):186–8. 10.1111/j.1479-828X.2006.00569.x [PubMed] [CrossRef] [Google Scholar]. 8. Kalogeropoulos D, Sung VC, Paschopoulos M, Moschos MM, Panidis P, Kalogeropoulos C. The physiologic and pathologic effects of pregnancy on the human visual system. J Obstet Gynaecol. (2019) 39(8):1037–48. 10.1080/01443615.2019.1584891 [PubMed] [CrossRef] [Google Scholar]. 9. Iancu G, Coviltir V, Iancu R, Corbu C. Particularities of myopia in pregnancy. Gineco Eu. (2013) 9:196–99. 10.18643/gieu.2013.196 [CrossRef] [Google Scholar]. 10. Balasubramanian K, Mathiyalagan S, Nagarajan G. A prospective study of changes in the refractive system of eye the during pregnancy. Int J Sci Study. (2017) 5(4):89–92. 10.17354/ijss/2017/342 [CrossRef] [Google Scholar]. 11. Usha C, Kalaiselvi B. A study on changes in the central corneal thickness among pregnant mothers in south India. Indian J Clin Exp Ophthalmol. (2019) 5(2):219–21. 10.18231/j.ijceo.2019.052 [CrossRef] [Google Scholar]. 12. Gong J-F, Xie H-L, Mao X-J, Zhu X-B, Xie Z-K, Yang H-H, et al. Relevant factors of estrogen changes of myopia in adolescent females. Chin Med J. (2015) 128(5):659. 10.4103/0366-6999.151669 [PMC free article] [PubMed] [CrossRef] [Google Scholar]. Dr. Preeti Sharma, Ph.D. (Scholar) Department of Pediatric Ophthalmology, Strabismus and Neuro-ophthalmology, Dr. Shroff’s Charity Eye Hospital, New Delhi, India. Corresponding Author: Subspeciality - Systemic Diseases

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 67 Head-Mounted Display (HMD) Assistive Technology for Low Vision and Vision Rehabilitation Suraj Singh Senjam, MD, Sneha Aggarwal, MSc, Abhijeet Beniwal, MD, Radhika Tandon, MD, Jeewan Singh Titiyal, MD Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, India. Abstract: In recent years, Head Mounted Display (HMD) Assistive devices are gaining global attention in terms of low vision management. To date, HMD devices have become one of the most advanced electronic-based wearable assistive devices that can enhance the residual vision of people suffering from low vision. By incorporating Augmented and Virtual Reality or mixed-reality computer technology which helps the image processing systems, HMD devices provide magnification, contrast sensitivity enhancement, illumination, increased field of view by minification process, color inversion, and auto-focus technology at all distances, thereby the device augments to improve the person’s visual function. Such device, but not all, also has built-in Optical Character Recognition software for textto-speech output, Artificial intelligence for face recognition, and object identification. The application of HMD technology in low vision and rehabilitation practices will be a new opportunity to extend additional benefits to those individuals with low vision that may not be addressed by traditional assistive devices. In the future, HMD technology, with more advanced computer technology and image processing and remapping strategies, can potentially provide a breakthrough in the management of individuals with low vision. Introduction Head Mounted Display (HMD) assistive technology is a type of electronic visual assistive device for a person with low vision that needs to be worn on the user’s head, thereby presenting information to the user’s eyes directly. Attaching HMD devices to the user’s head makes it a hands-free device for the end users. The first HMD device, the Visionic Low Vision Enhancement System (LVES) was developed by Visionic Cooperation in the 1990s.[1][2] Initially, HMD was designed for military purposes and their use. However, over time, due to the incorporation of computer technology and reduced cost, it becomes more accessible for industrial use and entertainment purposes. In recent years, HMD technology has improved a lot and become more prevalent in low vision and vision rehabilitation practices, especially in high-income countries. The modern HMD assistive technology has incorporated various vision enhancement technology to improve visual function, including acuity, customized vision enhancement system, contrast enhancement, improving the constricted field of vision, night vision, color vision, and even optical character recognition for text-to-speech and speech output artificial intelligence technology for face recognition and object identification.[3][4] Such vision enhancement is primarily with the help of Augmented Reality (AR) or Virtual Reality (VR) technology or a mix of the two incorporated into HMD devices. AR system superimposes a computer-generated world in a real-world environment, thereby enhancing the natural environment by adding virtual elements, that helps in vision enhancement of the end users. The hardware of the AR or VR system includes a display, processors, sensors, and an input system. This display is positioned close to the eyes and attached to a headset worn on the forehead of the users. This display system, mounted on the forehead, is known as HMD. The assistive device having such a display is named an HMD device. Based on the usability of the display, HMD can be categorized into two types Optical See-Through Display (non-occluding the user’s view) and Video See-Through Display (occluding the user’s view).[5] The Optical See Through (OST) works whose display combines virtual components with a view of a real-world environment. OST display is a display that is most commonly used in AR environments as it allows users to see the real world without occluding the user’s view, i.e., usually looking through a semitransparent mirror. Therefore, the main advantage is it does not impede the vision and in case of power or device failure, they do not impede the user’s view.[6] Such a display system can be used to improve mobility to a great extent. For example, AceSight S. Further, based on the display technology, an OST device can be either a near-eye display in which the display lies just in front of the user’s eye, e.g., AceSight S, or retinal projection where the images project in front of user’s retina (no transparent mirror attached), e.g., Google glasses. The Video See-Through Display (VST) works with a display that physically blocks the user’s view (occluded display) but combine virtual contents along with real environment scene. Therefore, such a display directly eliminates the path between the user’s eyes and their real environment making a total virtual world while using the device, so-called Virtual Reality (VR). It Subspeciality - Low Vision Rehabilitation

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 68 blocks the natural view of the environment but allows the users to see the real world as an entirely virtual world mode via a video captured by a camera. Such occluded display (VR devices) has been conventionally used for entertainment applications.[6] Examples of such types of HMD devices are eSight, Oculus Rift, and Vision Jordy. As of today, HMD assistive devices are not very much used for low vision and vision rehabilitation practices in low-middle-income countries, though their application is increased in high-income countries. Although the practical benefits of HMD assistive devices have not been studied and documented extensively, evidence is increasing that HMDs based on augmented, virtual or mixed reality have enhanced visual function in people with any form of low vision, and thereby help in terms of executing daily living activities, reading, face or object recognition, obstacle avoidance, and help to improve the quality of life.[7][6] The purpose of the article is to present an overview of various types of HMDs that currently use in low-vision rehabilitation services at Dr. Rajendra Prasad Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi. Such an overview article can help to understand various types of HMD assistive devices and their potential applicability in low vision and vision rehabilitation services. Types of HMD Assistive Devices eSight Eyewear The first eSight was developed by a Canadian electrical engineer in 2006. eSight is a based on virtual reality that helps people with peripheral vision loss to see a wider field view but can also be used for a patient with mild central field defect. It has adjustable arms on both sides (Right and Left) that help to wear the device over prescription glasses, and an adjustable halo band that allows it to fit children and adult users securely (Figure 1). eSight is powered by 2 rechargeable lithium-ion batteries, each can last up to 3 hours of continuous use with 256 GB storage and 3 integrated speakers. eSight has a touchpad and menu control which is integrated into the headset along with an external wireless remote control. Apart from this, it can be web account controls by using eSight mobile apps. The device can be connected with Wi-Fi, Bluetooth, and HDMI and USB inputs. It has also a built-in 18 MP camera which gives a high-resolution (1280X960) image. The autofocus software helps with image stabilization and personalization. eSight can enhance the diagonal field of view by nearly 40 degrees. It works best for a patient having best-corrected vision acuity (BCVA) between 6/18 to 1/60. The device can be used for patients suffering from following eye problems with great success. 1. Glaucoma, 2. Retinitis pigmentosa. 3. Stargardt disease 4. Optic atrophy 5. Rods and cones dystrophy 6. Albinism 7. Diabetic retinopathy 8. Macular degeneration Figure 1: eSight Eyewear with remote control. Figure 2: AceSight S model with wired remote control. AceSight S Model AceSight-S was developed by Zoomax Technology Co. Limited in collaboration with University of California, Los Angeles and Massachusetts Institute of Technology. The device employs Augmented Reality (AR) technology and feature two full HD displays that float in front of each eye. It has an 8-megapixel camera and a 45° field of view per eye (Figure-2). A tracking autofocus camera between the eyes captures everything the user looks at and presents everything in the magnified form up to 15x normal size. A hand-held controller allows the user to adjust magnification, colors and contrast, and enhancement of the edge of the object. It also has a rechargeable Li-ion battery that lasts more than 4 hours on a single full charge. AceSight is also useful for a patient with peripheral vision loss with its narrow mode. Properties • AceSight is ideally suited to individuals with a visual acuity range from 6/36 to better than 1/60 due to any type of ocular problems. • Patients whose vision is less than 1/60 cannot get fully Subspeciality - Low Vision Rehabilitation

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 69 benefitted from this device. • AceSight helps to do routine daily indoor activities, including watching Television. OXSIGHT Smart Glasses OXSIGHT Crystal OXSIGHT crystal is an HMD device based on AR technology designed for people with peripheral vision impairment (PVI), sometimes known as tunnel vision. (Figure-3). This device can enhance horizontal field of vision upto 68 degrees. The device is powered by battery that can last around 3 hours of continuo sues. The front clear screens allows social interaction or to view the real environment. The device is useful for patients suffering from Retinitis pigmentosa, High Myopic degeneration and Glaucoma. OXSIGHT Onyx OXSight Onyx is a VR based HMD devices designed for individuals with central vison loss (Figure-4). Onyx helps in reading text, recognizing faces, or objects, and the users can Figure 3: OXSIGHT Crystal. Figure 4: OXSIGHT Onyx. Figure 5: JORDY Wearable glasses. JORDY Wearable Glasses This device was developed through joint research between NASA’s Stennis Space Centre and Johns Hopkins University and US. Department of Veterans Affairs. JORDY is a battery operated HMD device that can be worn like a pair of glasses to see near, far, and everything in between (Figure-5). It has 720 p High Definition-60 FPS (Frame per second), autofocus camera for distance, intermediate & near viewing, 30X magnification, but can magnifies up to 50X, color select, locator, freeze & focus lock functions, dual display with a wide field of view, 5-level brightness control, adjustable top strap, and nose piece for optimum comfort, glare reduction eyecup shield, lens holder for your prescription, headset weight: 8 oz, control unit with a built-in rechargeable battery that lasts more than 4 hours on a single full charge. It can also be used as a desktop magnifier. Jordy enables the person with low vision to read, write, and see in any environment including work, home, and school. It also enables patients to enjoy watching movies, TV, Play games. It is not designed for mobility, walking, or running. Iris Vision IrisVision Live is a smartphone-based-HMD assistive device based on Virtual Reality technology (Figure-6). The smartphone in IrisVision acts as a camera, image processor and display which is inserted into VR based headset. The device can easily adjust accordingly to enhance vision, and change the mode as automatic night mode, and a TV mode. Additionally, the device can also increase the users’ horizontal field of vision up to 70 degrees and add or remove shade for lower light sensitivity depending on light conditions. It has 8x magnification and adjustable built-in lenses, and a re-chargeable battery lasts more than 2 hours. The device is useful for person suffering the following eye conditions. 1. Age Related Macular Degeneration 2. Macular hole or oedema 3. Stargardt Disease 4. Macular Dystrophy 5. Lebers Hereditary Optic Neuropathy (LHON) Subspeciality - Low Vision Rehabilitation

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 70 Figure 7: NuEyes Pro 3 (source: https://www.nueyes.com/pro3). Figure 6: Smartphone-based HMD assistive device (VR display, smartphone, a remote control, source: JH Yeo et al). Conclusion HMD assistive technology represent a new approach to address vision loss, particularly low vision for both peripheral and central loss of vision. Using HMD technologies offer many advantages in terms of enhancing vision that may not be addressed by existing conventional low vision aids, such as stand or handheld magnifiers, reading lenses, and closed-circuit television system (CCTV). With advanced in HMD technology, the option with assistive technology for vision impairment to manage low vision will be widen substantially in the future. Conflict of Interest The authors do not have any conflict of interests. Acknowledgment We are grateful to the WHO, Southeast Asia Regional Office in providing some of the HMD assistive devices for low vision and vision rehabilitation service. enhance distance, intermediate and near vision acuity, reading performance, facial recognition and further improving quality of life. The device is weight of around 500 gm and smartphone with a total screen resolution of 2960x1440 pixels (570 pixels per inch) and presented a digital image on an AMOLED screen. The lenses in the headset provides around 110 degrees diagonal field of view and offered up to 10X magnification while the software (Relumino software) offered up to 8x magnification. The software processed the image taken by camera of the smartphone and modified with virtual elements and displayed in the binocular viewing system of the VR headset in real time (IrisVision).[8] The device is best for low vision patients having a BCVA 6/18 upto 1/60 regardless cause of vision impairment. NuEyes Pro 3 NuEyes Pro 3 is one of highly advanced HMD assistive devices based on AR technology in contrast to previous version that was VR based HMD (Figure-7). The device is weight approximately 100 gm with a pair of glasses, and 13-megapixel 4K display. It provides around 52 degree field of view diagonally. It also enhances vision performance like other HMD and help patients with both central and peripheral vision loss. The device can be connect with smartphone, tablets, computers and iPad. The device has buit-in OCR enable feature. References 1. Massof RW, Rickman DL, Lalle PA, Johns Hopkins T. LOW VISION ENHANCEMENT SYSTEM. 2. Massof: Low vision enhancement: Vision for the future - Google Scholar [Internet]. [cited 2023 Jun 24];Available from: https:// scholar.google.com/scholar_lookup?hl=en&volume=4&publication_ year=1994&pages=32-35&journal=Eyecare+Technol&author=Mas sof+R.W.&title=Low+vision+enhancement%3A+vision+for+the+fu ture 3. Deemer AD, Bradley CK, Ross NC, Natale DM, Itthipanichpong R, Werblin FS, et al. Low Vision Enhancement with Head-mounted Video Display Systems: AreWe There Yet? Optom Vis Sci [Internet] 2018 [cited 2023 Jun 23];95(9):694. Available from: /pmc/articles/ PMC6119088/ 4. Lorenzini MC, Wittich W. Head-mounted Visual Assistive Technology-related Quality of Life Changes after Telerehabilitation. Optom Vis Sci [Internet] 2021 [cited 2023 Jun 26];98(6):582–91. Available from: https://pubmed.ncbi.nlm.nih.gov/34081648/ 5. Ehrlich JR, Ojeda L V., Wicker D, Day S, Howson A, Lakshminarayanan V, et al. Head-Mounted Display Technology for Low Vision Rehabilitation and Vision Enhancement. Am J Ophthalmol [Internet] 2017 [cited 2023 Jun 23];176:26. Available from: /pmc/articles/ PMC5580828/ 6. Htike HM, Margrain TH, Lai YK, Eslambolchilar P. Ability of HeadMounted Display Technology to Improve Mobility in People With Subspeciality - Low Vision Rehabilitation

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 71 Low Vision: A Systematic Review. Transl Vis Sci Technol [Internet] 2020 [cited 2023 Jun 26];9(10):26–26. Available from: https://doi. org/10.1167/tvst.9.10.26 7. Lorenzini MC, Wittich W. Head-mounted Visual Assistive Technologyrelated Quality of Life Changes after Telerehabilitation. Optom Vis Sci [Internet] 2021 [cited 2023 Jun 26];98:582–91. Available from: www. optvissci.com 8. Yeo JH, Bae SH, Lee SH, Kim KW, Moon NJ. Clinical performance of a smartphone-based low vision aid. Sci Rep [Internet] 2022 [cited 2023 Jun 30];12(1). Available from: /pmc/articles/PMC9232610/ Dr. Suraj Singh Senjam, MD Vision Rehabilitation, Assistive Technology, Community Ophthalmology, Dr. Rajendra Prasad Centre for Ophthalmic Sciences, AIIMS, New Delhi, India. Email: [email protected] Corresponding Author: Subspeciality - Low Vision Rehabilitation

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 72 Malingering: A Non-Organic Disorder in Ophthalmology Sanjeev Kumar Nainiwal, MD, DNB, MNAMS, Siddharth Maanju, MS Department of Ophthalmology, Sawai Man Singh Medical College & Hospital, Jaipur, Rajasthan, India. Malingering is a condition in which patients consciously and voluntarily produce their symptoms. The essential features of malingering are the intentional production of false or grossly exaggerated physical or psychological symptoms, motivated by external incentives such as avoiding military duty, avoiding work, obtaining financial compensation, evading criminal prosecution, or obtaining drugs. It can be divided into several different categories, which may include simulation of a nonexistent disease, elaboration of preexisting disease and attribution of disability to different cause, usually in the setting of potential complications.[1] Malingering must be differentiated from a fictitious disorder with physical symptoms, also called Munchhausen syndrome. Patients with this condition intentionally produce physical symptoms and signs, some of which may be ocular. These include swelling and redness of the conjunctiva simulating orbital cellulitis, scarring of the eyelids and conjunctive and even chorioretinal scarring. In contrast to malingering where compensation, avoidance of military services, and related issues are at stake, patients with Munchhausen syndrome are thought to harbor a personal internal need to adopt the role of a sick person. Patients whose symptoms seem truly independent of volition are said to have a somatoform disorder or psychogenic disturbance. Examples of psychogenic disturbance are body dysmorphic disorder, conversion disorder (hysteria, conversion reaction), hypochondriasis, and somatization disorder. A body dysmorphic disorder is characterized by a patient’s perception of a single physical defect, most often in the facial region, including the eyes. The patient is preoccupied with this sign even though it is minimal (e.g., a mild ptosis or anisocoria), or is not present at all. Hypochondriasis is the fear of, or strong belief in the presence of specific serious physical conditions accompanied by excessive self-observation with the reporting of numerous physical signs and symptoms. It differs from body dysmorphic disorder in that it includes both symptoms and signs from multiple organ systems throughout the body. A conversion disorder is diagnosed when alterations or a loss of physical functioning are present that seem to express a psychological conflict or need rather than indicating organic illness. The examples of this disorder are hysteria or conversion neurosis. Patients with such disorders subconsciously obtain both primary gain (e.g., protection from trauma or reduction of stress) and secondary gain (e.g., increased attention). A somatization disorder features recurrent and multiple somatic complaints. As in hypochondriasis, multiple organ system disorders may be mentioned, but the patient’s descriptions are vague, along with anxiety or depression, which are usually present. Unfortunately there remains a large group of patients in whom a clear distinction between malingering, Munchhausen syndrome, and psychogenic or somatoform disturbances cannot be made easily. In such cases, the ophthalmologist must be content with the knowledge that there is no organic basis for the patient’s signs and symptoms and should manage the patient accordingly. Clinical Evaluation The clinician faced with a case of suspected non organic visual loss commonly feels frustrated or even gets angry at being required to cope with a patient who may exaggerate or falsify claims of visual disability, particularly when such a patient may be hostile and uncooperative. In such situation(s) it is important to avoid these attitudes, and a friendly, sympathetic approach should be adopted, while not providing support to his unproven claims of visual impairment. Patients are more cooperative to testing if when they sense their clinician as supportive and interested in their welfare. Moreover it is important to maintain the objectivity of the tests performed throughout to give the clinician results that help him differentiate organic from nonorganic disease.[2] Patient’s Attitude The way, the patient acts during the history taking and examination may be helpful. Patients who are truly blind in both eyes tend to look directly at the person with whom they are speaking, whereas, patients with non-organic blindness, particularly patients who are malingering, often look in some other direction. Malingerers are usually anxious and may be hostile and uncooperative during and may often refuse or delay the responses on questioning or testing. However, occasionally, they display overly solicitous behavior in an attempt to convince the examiner of their sincerity in attempting to comply with instructions, while avoiding responses and tests that might reveal the lack of objective evidence of disease. On the other hand, patients with hysteria are usually quite Subspeciality - Expert Corner

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 73 cooperative in testing and may be paradoxically unconcerned by their symptoms. They are frequently suggestible (Table-1). Malingering Hysteria External incentives (e.g. financial reward or avoiding military service) – present Malingers are more likely to be suspicious, uncooperative, aloof and unfriendly Malingerers may try to avoid diagnostic evaluations and refuse recommended treatment Malingerers likely to refuse employment opportunities designed to circumvent their disability. Malingerers more likely to provide descriptions of events precipitating their illness. Absent Patients with hysteria are friendly cooperative, appealing, dependent and clinging Patients with hysteria try to welcome evaluation and treatment “Searching for an answer” Patients with hysteria are likely to accept such opportunities. Patients with hysteria more likely to report historic gaps, inaccuracies and vagaries. Table 1: How to differentiate malingering from hysteria. History Regardless of the type of nonorganic disorder, patients usually tend to attribute this problem to a certain incident, such as an accident, injury, or illness, and correlate its onset accordingly. The symptoms they present, may be non physiological in nature, like transient binasal visual-field defects or may be inconsistent with the physical finding, such as markedly decreased visual acuity in the presence of normal foveal sensitivity on automated perimetry. So, it is essential during evaluation to document the complaints precisely as inconsistencies in reported symptoms are often key elements in establishing the diagnosis. Examination The examination of all patients with a suspected non-organic disorder is directed towards three major goals. First the clinician should attempt to rule out inorganic cause for symptoms by performing a thorough and complete examination. No shortcuts are allowed for this category patients because, it should be kept in mind that some of these patients may also have organic disease. Second, organic findings should be distinguished from nonorganic findings. It is not uncommon for organic and nonorganic diseases to coexist (so called functional overlay), and the confusion generated may mask the treatable organic problems. Third, the clinician should meticulously record in the chart the features that support these conclusions. Many clinical tests are designed specifically to confirm nonorganic visual disorders. The clinician should become efficient in the performance of several of these tests, so that they may be accomplished quickly and smoothly, with desired proof being obtained before or even without the patient’s awareness of their nature. Visual Acuity Loss Decreased visual acuity is the most common form of nonorganic disorder. When the claim is that of severe visual loss (unilateral of bilateral), it is usually relatively easy to distinguish organic from nonorganic disease, rather than in cases who claim relatively mild bilateral impairment of vision.[3-5] The first goal of evaluation in either situations is to confirm or refute any component of organic visual pathway damage. So, special attention must be given in such cases to ward off the potential cases of visual loss, like uncorrected refractive errors (particularly, irregular astigmatism related to keratoconus, early irregularities in the lens, i.e. oil droplet cataract), retinopathies (such as mild cystoid macular edema, pigmentary changes of stargardt’s disease, mild central serous choroidopathy, retinitis pigments etc.), optic neuropathies or damage to the central nervous system visual pathways, most often in absence of other neurologic abnormalities, located in the occipital lobes. Tests for Examination: Observation It is useful to observe the way in which the patient who complaints of severe vision loss or very narrow tunnel vision, maneuvers around objects placed in his/her path om the way to the examining chair. A truly blind person moves cautiously and bumps into things naturally, whereas a hysteric avoids objects and a malingerer goes out of his way to dump into objects.[6] Optokinetic Drum Test If a patient claims no light perception, only light perception or only bare hand motions in one or both eyes, one can use a rotating optokinetic drum or horizontally moving tape to produce a horizontal jerk nystagmus which indicates intact vision of at least 20/400 when testing a patient who claims complete loss of vision in only one eye, the test should be begun by rotating the drum or moving the tape in front of the patient with both eyes open. Once, a good opt kinetic nystagmus is elicited, close the unaffected eye with the palm of the hand or a hand held occlude. The patient with nonorganic loss of vision in one eye will continue to show the jerk nystagmus. Menace Reflex Patient blinks his/her eyes on sudden visual threat. Sudden Strong Illumination Test On exposure to a sudden onset of strong illumination of light, it becomes difficult for a malingerer to suppress reflex tearing. Signature Test On asking the patient to sign his/her signature, a patient with organic blindness can easily sign his/her name without difficulty, whereas the patient with blindness caused due to malingering may produce an extremely bizarre signature.[7] Subspeciality - Expert Corner

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 74 Mirror Test This test is helpful in detecting visual function in an eye that is said to have either no light perception or only light perception. A large mirror is held in front of the patient face, and the patient is asked to look directly straight ahead into the mirror. The normal eye should be occluded if the patient claims blindness in only one eye. Otherwise, both eyes are left open. The mirror is then rotated and turned from side to side causing the image in the mirror to move. The development of nystagmus or nystagmoid movement of the eye(s) indicates that the patient can see moving images in the mirror and thus is not blind.[8] Diplopia Test of Miller Place an eight diopter loose prism, base down in front of the affected eye with presumed monocular blindness and ask the patient to view a distant light target. A report of diplopia indicates that the affected eye is not blind.[9] Unorthodox Approaches Presentation of unusual shocking visual stimuli may produce an emotional response in a patient claiming inability to see formed images. For example: a sudden test of recognition of an objectionable phrase or lewd picture may elicit a response in the claimed blind eye in malingering patient. Test of Proprioception This is a test of proprioception and not of vision. Ask the patient to touch the tip of the nose with a finger. A blind person can easily touch the nose as his proprioceptive response is normal. But a malingering patient pretends to not be able to touch his nose as he associates this test with his visual complaint. Visual Evoked Response (VER) Correlation exists between check size and level of acuity. Although difficult, it is sometimes possible to consciously alter response to pattern-reversal stimulation with convergence, meditation, or by intense concentration.[10] Fogging Tests Ask the patient to read the Snellens’ eye chart with both his/her eyes open. Now add progressively more plus power lenses in front of the sound eye while the patient keeps reading. Final line read is the patient’s visual acuity in the suspected eye. Cross cylinder technique. Place two strong cylindrical lenses of equal power of opposite signs (plus and minus) at the same axis in a trial frame over the sound eye, and ask the patient to read with both the eyes open. Now rotate one lens, 45 from the previous axis while the patient keeps reading. The final line read is patient’s visual acuity in the suspected eye. Test By Pseudorefraction This test can be used for detection of a nonorganic disorder in patients who claim to have unilateral severe visual loss. Place a high power plus lens in front of the normal eye and a lens with very minimal power in front of other eye, claimed to have decreased vision. The patient is then told to read the chart with both eyes open. If the patient continues to read chart, he or she must be using the affected eye. Color Tests: Red-Green Duochrome Test Red-green glasses used with a red and green Duochome slide superimposed on the normal vision chart can be used to induce a patient to read with an eye that supposedly cannot are (or cannot see well) by making the patient think that he or she is using both eyes. In this test, the eye behind the red lens will see the letters on both sides of the chart, whereas, the eye behind the green lens will see only those letters on the green side of the chart. The lenses are arranged so that the red lens is over the eye with decreased vision, and the patient is then asked to read the chart with both eyes open. If the patient reads the entire line, it is obvious that the abnormal eye must be functioning better than the patient claims. Red-Green Glasses and Warth 4-Dot Test Patient should see appropriate number of dots. Polaroid Glasses and Vectographic Slides Normally the eye sees different portions of the eye chart. If the patient reads the entire line, both the eyes are being utilized. Pupillary Response The pupil of a patient who cannot perceive light with either eye because of bilateral retinal, optic nerve or optic tract lesions, or because of damage to the optic chiasma do not react to light stimulus. Pupils that react to light stimulus in a patient who claims complete loss of vision in both eyes indicate either that the patient is blind cerebrally (usually from damage to the striate cortex, i.e. cortical blindness), or that the patient has nonorganic loss of vision. However, we should not forget about pharmacological mydriasis in a malingerer.[11] Stereoacuity Test Stereoacuity is directly proportional to Snellen’s acuity. A 40 seconds of arc stereoacuity is compatible with no worse than 6/6 Snellen’s acuity. Retinal Rest Test In the past, this was an effective therapeutic trial tool in the diagnosis and management of feigned blindness in the military services, where false claims of visual loss where relatively common in soldiers to attempt to avoid services, where false claims of visual loss were relatively common in soldiers to attempt to avoid service obligations. Such patients were informed that their visual loss was the result of “retinal fatigue” which required complete resting of the retinal tissues by eliminating as much sensory input as possible. They were hospitalized alone in a room with bilateral pressure bandage so that any tampering could be easily detected. They were kept on absolute bed-rest and allowed no visitors, radio or television sound, or sedatives. Only minimal conversation with the hospital staff was allowed, and visual acuity was checked daily. Miraculous visual recoveries were common place in such malingerers. Subspeciality - Expert Corner

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 75 Visual Field Loss Visual field loss is a less common symptom of nonorganic origin. The most common manifestations included generalized peripheral constriction, and central, and hemianopic patterns of field loss. The visual field defect of hysteria and malingering typically results in an alleged claim of marked peripheral or “tubular” construction. Unlike the organic causes of generalized field constriction, a tubular field maintains the same diameter, that is, it does not expand geometrically with increasing test distances. Thus, assessment of peripheral testing at least two viewing distances, which is easily accomplished at the tangent screen or even by confrontation field testing.[12] Eye Movement Disorders The two most common nonorganic eye movement disorders are spasm of the near reflex and voluntary nystagmus. Spasm of near reflex, also known as accommodative spasm, is occasionally related to some organic causes, like Chiari’s malformation, head injury, cerebellar tumors, and diverse central nervous system inflammatory diseases. However, the majority of cases are nonorganic in origin, occurring in anxious patients often with other nonorganic findings. The syndrome consists of episodic convergence, increased accommodation and miosis during which the patient complains of blurred vision (caused by induced myopia) and diplopia (caused by esotropia). Differentiation of this from bilateral abducent nerve palsy can be made by asking the patient to fixate a moving target monocularly, during which time full abduction is usually performed. Alternatively, oculocephalic maneuvers produce full range of motion. In addition, the miosis that invariably accompanies esotropia in the spasm of near reflex is not present with the abducens palsies. Voluntary nystagmus is a distinctive clinical phenomenon in which patients produce conjugate high frequency pendular horizontal oscillations of the eyes in intermittent bursts. As creation of those effects requires some effort, it is difficult for patients to sustain the nystagmus for more than a few seconds. Miosis is frequently present, associated with the convergence effort. It has been estimated that more the 5% of the population can produce voluntary nystagmus. It may be a familial trait, or in some cases, it may be learned. It should be differentiated from convergence retraction nystagmus by the mildly dilated pupils and the large pupils and the larger amplitude and lower frequency movements associated with attempted upgaze in the dorsal midbrain syndrome. Disclosure In documenting nonorganic visual disorders in medical records, it is essential to state in nonperjorative terms, the fact that no organic damage to the visual system was detected by the examination and to delineate the specific findings of the examination that confirm this fact, with the inconsistencies that suggest a nonorganic etiology. In cases involving disability, worker’s compensation or medicolegal claims, the simple statement that “no organic cause for the patient’s symptoms was found” in usually sufficient to convey the necessary implications to those involved. What to tell the patient varies with the circumstances. In medicolegal causes, no discussion should be done with the patient. If no legal action is involved, for adult causes, we can explain to the patient that no damage to the visual system has been demonstrated by the examination. This, of course, in not good news to the malingerer, but we can blithely proceed, even in the presence of developing hostility, to explain that when all of our testing shows no evidence of damage, the problem typically improves over time and no treatment is required. Psychiatric help is not generally required or recommended unless obvious illness is apparent. In the case of a child with nonorganic visual disturbance, the approach is somewhat different. Most often, such children become satisfied with the explanation that these types of problems are seen often and that they usually go away with time. However, the parents often require more than this. We should discuss the problem in the absence of the child, informing them that the child see’s better than that has been measured by testing. It can be explained than children react to stress with physical symptoms, which are commonly ocular and recommend that the parents should consider any possible home or school stress that might have precipitated the condition. It should also be emphasized that the child should not be punished for such behavior, as it is often not a conscious occurrence. There is no need for recommending psychiatric evaluation, but they should be encouraged for follow-up to document recovery, which is common in children. It should be suggested that this recovery may occur within days to weeks or months, days to weeks or months, so as not to pressure the child to demonstrate recovery too quickly. Follow Up The majority of patients with non-organic visual disorders do not return to the clinician with ongoing symptoms. This might be because either the malingerer finds that the disorder does not produce the secondary gain desisted or the no malingerer is relieved to find that the clinician found no serious condition and goes about his/her activities. However, when patients do return for routine follow up they often demonstrate the same sings of nonorganic visual impairment. A recovery rate of greater than 75% have been reported in children within several months. References 1. American Psychiatric Association, American Psychiatric Association DSM-5 Task Force. 5th ed. Arlington: American Psychiatric Association, Washington, DC;2013. 2. Dinvijay S, James M, Saxena R, Menon V. Visual impairment with a normal fundus. Kerala J Ophthalmol. 2012;24(1):19–24. 3. Apple DJ. Sir Nicholas Harold Ridley: all’s well that ends well [obituary]. Am J Ophthalmol. 2002; 133:131-133. 4. Ridley NHL. Intraocular acrylic lenses. Trans Ophthalmol Soc UK Oxford Ophthalmol Congr. 1951; 71:617-621. Subspeciality - Expert Corner

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 76 5. Ridley NHL. Intraocular acrylic lenses after cataract extraction. Lancet. 1952; 1:118-119. 6. Gundogan FÇ, Sobaci G. Malingering in practice of ophthalmology clinics. Turk Klinik J Med Sci. 2010;30(Supp 2): s53–60. 7. Optometry 2007;10(78): 523-533. 8. Beatty S. Nonorganic visual loss.1999; 75(882):201-207. 9. Gandhi R, Amula GM. Malingering in ophthalmology. E Medicine specialties. ophthalmology. unclassified disorders. update Sep 2, 2009. 10. Apple DJ. Sir Harold Ridley receives England’s highest honor. Surv Ophthalmol. 2000; 44:542. 11. Bruce BB, Newman NJ. Functional visual loss. Neurol Clin. 2010;28(3):789–802. 12. Hsu JL, Haley CM, Foroozan R. Target visual field: a technic to rapidly demonstrate nonorganic visual field constriction. Arch Ophthalmol. 2010;128(9):1220–1222. Dr. Sanjeev Kumar Nainiwal, MD, DNB, MNAMS Senior Professor Ophthalmology, Sawai Man Singh Medical College & Hospital, Jaipur Rajasthan India. Corresponding Author: Subspeciality - Expert Corner

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 77 2 Millimetre Chord Manual Small Incision Cataract Surgery: New kid on the Block Amulya Sahu, MS, DOMS, Jatinder Bali, MS, MBA (Op Res.) Hindu Rao Hospital, Municipal Corporation of Delhi, Delhi. Background Presbyopia, the age-related loss of near vision, is a common condition that affects individuals as they grow older. It is characterized by a reduced ability to focus on near objects. Traditionally, monofocal IOLs have been used in cataract surgery to provide good distance vision. However, these lenses do not address presbyopia, and patients typically still require reading glasses for near vision. Multifocal IOLs were introduced as an alternative solution to achieve both distance and near vision without the need for glasses. These lenses have multiple focal points, allowing patients to see clearly at different distances. However, multifocal IOLs come with limitations such as increased cost, technical challenges during surgery, and the potential for patient-reported symptoms like glare and reduced contrast sensitivity. Due to the scalability challenge of multifocal IOLs, particularly in low and middle-income countries where cost is a significant barrier, there is a need to explore alternative solutions to achieve good near vision post-cataract surgery. One such alternative is the utilization of myopia or myopic surgically induced astigmatism in cataract surgery. Studies have shown that patients with myopia or myopic astigmatism can experience improved near vision without compromising distance vision or binocularity. The myopic defocus increases the depth of focus, allowing for better near vision. Similarly, myopic astigmatism, can contribute to enhanced near vision due to increased depth of focus. The concept of utilizing myopia or myopic astigmatism for near vision after cataract correction has gained attention in research and clinical practice. Studies have explored factors associated with good near vision in patients who have undergone cataract surgery with monofocal IOLs. These factors include the amount and type of refractive error, type of astigmatism, corneal multifocality, axial length, and increased depth of focus with pupillary constriction during accommodation. Understanding the relationship between myopia/myopic astigmatism and near vision can help guide surgeons in planning cataract surgeries to achieve better near vision outcomes. By targeting low degrees of myopia or myopic astigmatism, it may be possible to improve near vision post-cataract surgery and reduce the dependence on reading glasses or multifocal IOLs. Exploring the potential benefits of myopia or myopic astigmatism for near vision after cataract correction is a promising avenue to address presbyopia in patients undergoing cataract surgery with monofocal IOLs. By leveraging the increased depth of focus associated with myopic defocus, surgeons can potentially improve patients’ near vision with minimal compromise of distance vision, providing a low-cost and sustainable solution for presbyopia correction. The standard manual small incision surgery induces anastigmatism of about - 0.75 to -0.9 dioptres. This can be placed on the steeper to reduce post operative astigmatism to leave behind a minimal myopic astigmatism postoperatively. However, when the pre existing is astigmatism is very low then the incision needs to be decreased in size further. 2 millimetre small incision cataract surgery with backward cuts has been practiced for almost half a decade now. It induces an astigmatism of about 0.22 to 0.42 dioptres in different studies. It is of great use in patients who haveminimal astigmatism pre operatively. Surgical Technique This article describes a surgical technique for cataract surgery known as 2-mm chord manual small-incision cataract surgery (MSICS) with parallel back cuts and phacofracture. The procedure involves several steps and specialized instruments. The surgery begins with the creation of a fornix-based conjunctival flap using conjunctival spring scissors. The episcleral tissue is carefully cleaned, and bleeding is controlled using wetfield cautery. A sterile Johnson bud and gentle pressure are used to create a clear surgical field, and a 2-mm mark is made on the steep axis using a stained caliper. Next, an external curved incision with 2 mm chord length is made, 1.5 mm away from the limbus. The ideal depth for the scleral tunnel is about 200 µm, which can be marked using a diamond blade or Bard-Parker knife. A 45-degree curvedcrescent-blade is used to extend the incision forward, penetrating about half the thickness of the sclera and cornea. The depth of the incision is determined by observing the crescent through the sclera and cornea. Adjustments are made to ensure the proper depth is achieved, avoiding complications like perforation or premature entry. The orientation of the crescent blade is crucial, remaining parallel and tangential to the sclera. The tunnel is dissected forward, creating a sloping shape into the cornea, and extending it for 1 to 2 mm inside the clear cornea. The length of the tunnel is measured between the external Subspeciality - Surgical Technique

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 78 and internal lips or incisions. The technique can handle up to cataract of any C (1–5) or any P (1–5) to grade NC4 NO4 as graded by the LOCS III classification. It is not advised if the corneal endothelium is compromised. Pockets are created on both sides by dissecting through the cornea into the sclera using a crescent knife, reaching the end of a 1.5-mm parallel scleral back cut induced from either end of a 2-mm scleral frown incision. This results in a convex outward geometry with a truncated concavity at the top of the tunnel. The back cut from the concavity can be extended in either direction. The internal lip, a curved entry incision, is made using a keratome after creating the side pockets and completing capsulorhexis. The direction of the crescent blade needs to be adjusted when transitioning from the sclera to the cornea at the limbus, as the cornea offers greater resistance. The crescent blade should follow the curve of the eyeball in both the side pockets and the corneal extension. The internal lip, the curved entry incision, is made using a keratome after creating the side pockets and completing capsulorhexis. To enter the cornea, the keratome tip is dipped backward, and the internal lip is extended toward the limbus in a curvilinear fashion in either direction. It is recommended to use viscoelastic in the anterior chamber through a side port to stabilize the eyeball before using the keratome. The internal lip is extended curvilinearly in both directions from the central entry point. The internal lip should not touch the limbus at any point. Tunnel width refers to the distance between the external scleral incision and the internal corneal entry incision. Pocket tunnel dissection should extend forward into the cornea by 1 mm beyond the vascular arcade, into the clear cornea in front of the vascular arcade. For a self-sealing wound, the keratome should cut in a forward and lateral movement rather than a backward and lateral one to maintain valve action. A thick internal lip may hinder the self-sealing mechanism. The keratome used for cutting should always be sharp to minimize the risk of Descemet’s membrane detachment. Cortical cleaving hydrodissection is performed using a bent cannula to tent beneath the anterior capsule, creating a freely rotating nucleus. Dispersive viscoelastic is injected into the anterior chamber to protect the endothelium and facilitate nucleus prolapse by nudging at the equator with a modified dialler. Additional OVD is injected above and below the nucleus for further protection and to manipulate the iris and bag position. Sahu’s modified vectis (SMV) is used to maneuver under the nucleus, while a flattened tip visco cannula is employed to crack the nucleus by taking small bites at a time. SMV design prevents the nucleus from slipping away, and the visco cannula gently pushes one heminucleus away while bringing it out of the tunnel along the longitudinal axis. The author prefers using a special instrument for globe stabilization and avoids using forceps on the tunnel flaps. The first heminucleus can be brought out using the sandwich technique with the vectis and visco cannula in posterior and anterior positions, respectively. Liberal use of viscoelastic is recommended. The second heminucleus can be removed using the vectis or the sandwich technique. Cortical cleanup is performed using a Simcoe cannula. Foldable intraocular lenses can be implanted through this incision. Parallel back cuts are 1.5 mm for foldable lenses and 3 mm for non-foldable lenses. Lens implantation is done in the bag, and the lens may be dialed into position if required. Intracameral moxifloxacin is administered before closing the incision to prevent infection, and the wound integrity and intraocular pressure are checked. Figure 1: Conjunctival Peritomy. Figure 2: Wetfield Cautery. Subspeciality - Surgical Technique

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 79 Figure 4: 1&2 - Making the 2 millimetre incision. Figure 3: Marking 2 millimetre chord. Figure 5: Side Port Entry. Figure 6: Cystitome. Figure 8: Hydrodissection and Nucleus Prolapse. Figure 7: Capsulorhexis/CCC. Figure 9: 1&2- Phacofragmentation and removal. Subspeciality - Surgical Technique

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 80 Figure 10: Nucleus removal. Figure 11: Cortical Cleanup and Pseudophakos. The advantages of this technique included lower surgically induced astigmatism compared to classical manual smallincision cataract surgery and comparable corneal endothelial counts. In conclusion, 2-mm manual small-incision cataract surgery with parallel back cuts and phacofracture is a promising surgery for cataract surgeons, particularly in developing countries like India, regardless of access to phacoemulsification machines. Further Readings Sahu A, Bali J, Sahu C, Mishra D, Heda A, Deori N. Early postoperative astigmatism in 2-mm manual small incision cataract surgery with phacofracture. Indian J Ophthalmol. 2022 Jun;70(6):1997-2001. doi: 10.4103/ijo.IJO_308_22. PMID: 35647968; PMCID: PMC9359277. Dr. Jatinder Bali, MS, MBA (Op Res.) NBEMS Course Coordinator, Hindu Rao Hospital Municipal Corporation of Delhi, Delhi. Corresponding Author: Subspeciality - Surgical Technique

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 81 Combined Manual Small Incision Cataract Surgery and Trabeculectomy by M Incision A Procedure Jitender Singh Roodkee, DO Block Medical Officer(SPL), Civil Hospital Sunder Nagar H.P. Introduction With the advent of newer drugs, glaucoma is mainly managed by drugs and trabeculectomy a procedure is delayed. Trabeculectomy however is better neuro protective as it controls the IOP 24 hourly. This is a procedure is to make confident of ophthalmologists doing trabeculectomy plus MSIC with a single incision. As these days almost all ophthalmologists do MSICS and tunnel making is easy with cresent knife. Cautery of single area causes less scaring. Duration of morbidity is less and cost is also less. Both the surgeries take more time than of this procedure. M or W, flying eagle, straight and frown incision are famous to do both surgeries at single go. At number of centers phacoemusification- trabeculectomy are done to Cataract removal and control IOP, where this machine is not available, M incision combine surgery MSICS and Trabeculectomy can be done. Trabeculectomy Glaucoma is the second leading cause of blindness in world after cataract and visual recovery is almost irreversible. 57.5 million of population is affected which is approximately twenty percent of the world. The most common conventional and gold standard surgery performed for glaucoma is the trabeculectomy. Here, a partial thickness flap is made in the scleral wall of the eye, and a window opening is made under the flap to remove a portion of the trabecular meshwork. The scleral flap is then sutured loosely back in place to allow fluid to flow out of the eye through this opening, resulting in lowered intraocular pressure and the formation of a bleb or fluid bubble on the surface of the eye. Optimum intra ocular pressure (IOP) is maintained to save optic nerve neurons. Manual Small Incision Cataract Surgery (MISCS) Cataracts cause half of all cases of blindness and 33% of visual impairment worldwide. MSICS is a way to remove cataract by slcero-corneal tunnel Dr. Ruit developed MSICS and his colleagues at TiIganga Medical college, Nepal. It is an artistic surgery which has led ophthalmologist to do their innovation and every surgeon has its own style retaining the basics. MSICS has many types of incisions depending upon Incision planning, clear corneal, frown, smiling, straight etc. Key Words MSICS: Manual small Cataract incision surgery- MSICS, IOL:- intra ocular Lens, IOP:- intra ocular pressure. M Incision Combined MSICS and Trabeculectomy Both the surgeries at single procedure MSICS tunnel is made like M. Under V shaped flap sclera window is made. Since V flap can be sutured according to pressure control. All incisions are same; some says M, W and flying eagle. The main purpose is to make V shaped flap for trabeculectomy and side cuts for MSIC. Indications and Contraindications Main indication is POAG/Chronic angle closure glaucoma and significant cataract. Where combined anti-glaucoma drugs therapy fail to control IOP. Other indications are poor socioeconomic condition, far flung area as patient cannot come to review repeatedly. Even this surgery can be done in corneal opacities, shallow anterior chamber and small pupil pseudo exfoliation syndrome. Pre Operatives Routine ocular and systemic examination is done. IOP is controlled since MSICS has to be done it is controlled by Systemic and topically, IOP should be around 18 to 24 mm of Hg. Preoperative routine dilators and antibiotic are given. Procedural Highlights Fornix based conjunctival flap is raised; tenon is cut 2 mm behind conjunctival margin. With the help of calipers an imaginary base of 5mm on limbus is taken and 5 mm inverted equilateral triangle impressions are taken on sclera (each side 5 mm). 3 mm V shaped incision is made 2 mm behind limbus. 2 mm sideways horns are made which can be curved or straight (1mm horizontal and 1mm down) Total breadth of sclera incision is made near to 7 mm. Flap or tunnel is made by cresent blade. Mytomycin Can be applied here for 2 minutes and washed properly. Subspeciality - Surgical Technique

DOS Times Volume 29, Number 4, July-August 2023 www.dosonline.org/dos-times 82 Figure 1: Incision Making. Figure 2: Bleb. Routine manual Small Incision Cataract Surgery is done. IOL is implanted in bag. Injection Pilocarpine is instilled in anterior chamber Viscoelastic is instilled in anterior chamber. Routine trabeculectomy is performed. Single suture is taken at apex of scleral flap with 10-0 nylon or more depending on preoperative IOP and target IOP. Releasable suture can be applied Viscoelastic is washed and A/C is formed by balanced salt solution better with air. Tight closure of Conjunctiva is ensured with 10-0 nylon. Bleb is formed through side port Balanced Salt Solution. Post Operative Follow Up Medicine Eye drop Nepafenac, 0.1% QID 15 day Eye drops Moxifloxacin 0.5 1% plus predacetate on reducing dose 45 days lubricant 45 days Tab Ciprofloxacin 500 mg BD 3 days Tab Diclofenac 60 mg BD 3 days Conjuctival 10 nylon to be removed at 30 to 45 days Patient is advised to take care of eye as of any IOL surgery. On first post operative day of trabeculectomy is always very important. Due to numbers of complication to it lots of ophthalmologists do not dare it to do. But these can be managed very well, if there is shallow anterior chamber then leakage is tested by Siedal test, if the leak is from conjunctiva then pressure bandage given. If it is due to hyper filtration then re-suturing of the flap is needed o releasable suture can be applied again. There are other complications also but out of scope of this topic. Patient is followed up for bleb and IOP control for longer period. Discussions There is lots of backlog of cataract and glaucoma surgeries. As when the combined drugs therapy do not work the glaucoma surgery is done but if it associated with significant cataract it become surgery of choice as saves time, morbidity, money of the patient. In Government sector only few ophthalmologists has access for phacoemulsification machines so MSICS is their main surgery. Now the MSICS is very well established procedure. Therefore this procedure becomes surgery of choice. Procedure is simple tunnel and M flap[1][3][4] making and is very easy with cresent knife. It should be taught to everyone at medical college level. Cortical aspiration should be complete and neat. These combined MSIC and trabeculectomy behaves as gold standard trabeculectomies. Mytomycin can be used in Combined procedure.[2] Subspeciality - Surgical Technique

www.dosonline.org/dos-times DOS Times Volume 29, Number 4, July-August 2023 83 Figure 3: Can watch video on you tube https://youtu.be/6Kir5ZTkBuE References 1. Flying Eagle` Incision for Combined Manual Small Incision Cataract Surgery-Trabeculectomy. December 2016 Delhi Journal Of Ophthalmology 27(2):124-127. DOI:10.7869/djo.224. 2. Another study reported in Asia -Pacific journal of ophthalmology “mitomycin C augmented trabeculectomy with MSICS through tunnel flap technique at time of surgery mean IOP was 30.4+_4.46 reduction of IOP was 16.64 +_4.75mm Hg.( Venkatesh A comparative study of combined small-incision cataract surgery with sutureless trabeculectomy versus trabeculectomy using W-shaped incision A K Khurana 1, U Chawla, N Passi, Jyoti, Archana, Yogesh Affiliations expand.PMID: 21587324.DOI: 10.3126/nepjoph.v3i1.4272. 3. Modified small-incision cataract surgery for combined extraction - A comparative study of two techniques. Lubna Khan 1, Sonam Verma. Affiliations expand.PMID: 36308127PMCID: PMC9907250.DOI: 10.4103/ijo.IJO_1622_22. 4. A Descriptive Study on Visual Outcome and Intraocular Pressure Control after Trabeculectomy with Manual Small Incision Cataract Surgery in Patients with Glaucoma and Cataract. Naik GT, Achar P, Kripalini SH, Sajjan S.J Pharm Bioallied Sci. 2022 Jul;14(Suppl 1):S654-S657. doi: 10.4103/jpbs.jpbs_144_22. Epub 2022 Jul 13.PMID: 36110610. Dr. Jitender Singh Roodkee, DO Block Medical Officer(SPL), Civil Hospital Sunder Nagar H.P. Corresponding Author: Subspeciality - Surgical Technique

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