RPE & Demarcation lines (linear pigmented lines at RD edges), cysts in old RD may also form. These RDs may not need any treatment as they commonly don't progess. Tip-177..... Immunosuppressives (IS) in uveitis..... -NOT the primary therapy (except in Behcet's) -Used if steroids- producing serious side effects, unresponsive disease, can't be reduced to <10mg/day (prednisolone) for long term use. -No standard protocols available. -Take longer to produce effects (1-6 weeks). Start along with steroids for initial effect. -Prior consent, blood counts, LFT, RFT & systemic workup (rule out TB, HIV, etc.) essential. Regularly monitor. -Learn about 1-2 IS more (mostly antimetabolites) & use them in practice. -Broadly 4 groups... 1. Antimetabolites- MTX, Azathioprine (Imuran) & Mycophenolate mofetil (MMF). 2. Alkylating agents- Cyclophosphamide & Chlorambucil. 3. T-cell inhibitors- Cyclosporine & Tacrolimus 4. Biologics- Infliximab & Adalimumab.
-MTX cheapest & safest in children (Not pregnancy). Start with 7.5 mg once a week. Imuran started with 1mg/kg/day & increase gradually till 2mg/kg/D. -Biologics are costly, long term safety unknown. TNF inhibitors especially reactivate latent TB. Tip-178..... Conventional retinal lasers have each laser Pulse of few milliseconds (e.g. 100msec/0.1sec), while Micropulse laser has pulse duration of Microseconds (100-300). Hence Micropulse laser produces... - Subthreshold spot (clinically invisible). Thus, application is difficult to monitor. -Burn confined to RPE (desired site of treatment), thus no collateral damage (safer). Tip-179.... Current treatment of CSCR (CSR)..... -Observe (self resolving in 8-12 weeks) -Stop steroids in any form (reduce, if not so feasible) -Life-style change? NEWER/present treatments of Chronic or Recurrent CSCR..... NO definite treatment till today, however following tried.... 1. Anti-corticosteroid- Mineralocorticoid antagonist e.g. Eplerenone (25/50 mg OD/
Anti-HT drug available as 25 mg tablet, can cause hyperkalemia) & Spironolactone. 2. Anti-Helicobacter pylori antibiotics. H. pylori produces cytotoxins damaging choroidal vessels. 3. Anti-VEGF- useful only if associated with CNVM. 4. Retinal laser- for leaks outside FAZ. 5. PDT with reduced fluence (power). 6. Subthreshold Micropulse laser- (see Tip178) better than conventional laser. Safer for fovea. Tip-180..... White dot syndrome comprises a group of posterior uveitis disorders which are generally B/L (except MEWDS), idiopathic & affecting young or middle aged (except Serpiginous/any age & Birdshot choroidopathies/ 40-60 years aged females). Serpiginous choroiditis (GHPC) is a type of White dot syndrome which has morphologically similar Tubercular (infective) variant. Unlike classical Serpiginous choroiditis, Tubercular variant (Multifocal Serpiginoid choroiditis/MSC) is/has... -lesions not starting in peripapillary region, but away from disc & spreading to far periphery. -smaller, less confluent & multifocal lesions.
-associated vitritis more. -may be U/L. -responds to ATT with short steroid course. Tip-181.... Active chorioretinitis lesions are white to yellow in colour with fuzzy margins & sometimes mildly elevated, while healed lesions appear dull & greyish with pigmentation & discrete margins. Both may coexist. Tip-182..... Always think of Fungal Endogenous Endophthalmitis (FEE), if in seriously ill hospitalized patient on multiple tubes (IV, catheter, drainage tube, etc.), on fundus examination, shows ill-defined creamywhite lesions in retina; irrespective of whether he is asymptomatic or having red and painful eye. -Candida is the most common cause followed by Aspergillus. (Follow Tip-183). Opposite with Exogenous endophthalmitis. -Although rare, FEE is commoner than Bacterial EE. -Infection is blood borne, indicating fungemia. -Diagnosis is mainly clinical. Also by fungal identification in smear, PCR or culture of
specimen from vitreous/aqueous. Also from blood, etc. -Mainstay of treatment is systemic antifungals- IV/oral for 4-6 weeks. Intravitreal & PPV only if not responding or significant vitreous involvement. -Voriconazole (2x200mg tab BD) is the first choice (systemic & I-Vit inj.), being broad spectrum & safer followed by Amphotericin-B (nephrotoxic & poor intraocular penetration) & Caspofungin. Exogenous fungal endophthalmitis unlike Endogenous involves vitreous first & then retina (latter being of hematogenous origin). Tip-183.... Fungal endogenous endophthalmitis (FEE) is most commonly caused by Candida followed by Aspergillus. In FEE, Aspergillus lesions unlike those of Candida.... -start at macula -spread subretinal first, then vitreal. -spread faster than of Candida. -Angioinvasive causing hemorrhagic infarcts. -'String of pearl' appearance in retina/vitreous is classically seen with Candida.
Tip-184...... Geographic atrophy (GA) unlike Nongeographic atrophy (RPE degeneration/Incipient atrophy) of AMD is/has: -advanced form of AMD (other advanced form is Neovascular AMD. -discrete (well-defined) borders. -underlying choroidal vessels become visible -Never develops CNVM, but develops vision loss due to foveal atrophy. -FAF is the gold standard for monitoring progression (loss of RPE autofluorescence). However, both are dry forms of AMD & have no role of nutritional supplements as per AREDS-2 (See Tip-64). Tip-185.... Focal ERG is not used clinically. Used only in research. (see Tip-169) Multifocal (Mf) ERG is for focal macular diseases (tests macular cones only) Full-field (ff) ERG is a mass response from outer retina i.e. photoreceptors & bipolar cells mainly (central, mid & peripheral retina) and NOT the ganglion cells. Unlike conventional (ff) ERG, Pattern ERG....
1. Uses sine-wave gratings or checker-board instead of flash. 2. Pupils are not dilated. 3. Contact lens electrodes are avoided . 4. Mainly for Ganglionic cell activity, hence used in glaucoma also. 5. Has 3 deflections: N35, P50 & N95. N95 is negative deflection occuring at 95 milliseconds of stimulus & is from ganglion cells & macular cones. If P50 is OK, but N95 is defective, means ganglion cell disease. So to apply into clinical practice, one has to know which retinal disease affects which retinal layer or portion primarily. Tip-186.... Waveforms in VEP are different from those of mf (Multifocal) ERG. In VEP/VER also, N1, P1 & N2 deflections occur & are generated from entire visual pathway (ganglion cells to occipital cortex) & occur at 70, 100 &155 milliseconds respectively (latency time from giving the stimulus), while in pattern ERG, N1, P1 and N2 deflections occur at 35, 50 and 95 milliseconds respectively & are generated by ganglion cells and macular cones. VEP is non- localising (mass response from entire visual pathway); although macula is
over-represented in the visual cortex, VEP is more sensitive to optic nerve pathologies. Tip-187.... Serpiginous choroidopathy (Geographic helicoid peripapillary choroidopathy, GHPC) unlike APMPPE (Acute posterior multifocal placoid pigment epitheliopathy) lesions: 1. Start in peripapillary region (occasionally macular) 2. Confluent 3. Spread outward (creeping) at edges. 4. Chronic & recurrent 5. Activity & healing continues together. While APMPPE lesions occur in young adults, are non-recurrent, multifocal & noncreeping, self curing in 3-6 months. Tip-188.... In Hypertensive retinopathy grade-4 unlike CRVO: 1. Changes bilateral (B/L CRVO is rare, but possible; look for thrombo-embolism, systemic vasculitidis & hyperviscosity syndromes). 2. Less hemorrhages (extensive in CRVO) 3. Exudation more (both hard & soft). Less in CRVO, that too only soft.
4. Arterioles primarily affected (extensive venous engorgement & tortuousity in CRVO). Tip-189..... Five most important retinal diseases that have totally Extinguished ERG are (remembered by an acronymDOLARS): 1. Detachment of retina 2. Ophthalmic artery occlusion (see Tip-27) 3. Leber's Congenital Amaurosis (see Tip-139) 4. Aplasia of retina 5. RP (severe form) 6. Siderosis Tip-190.... CMV retinitis unlike ARN (Acute retinal necrosis by Herpes) has: 1. No vitritis 2. Extensive hemorrhages (Pizza-pie or Cottage cheese with ketchup appearance). 3. Mainly posterior pole & venous involvement (mid-peripheral & arterial in ARN). 4. Slow progression 5. Occurs in immuno-compromised only (ARN possible in immunocompetent also). Tip-191..... Facts about Microperimetry: 1. Primarily for macular diseases (no macular fixation compulsory unlike conventional perimetry).
2. Tests macular sensitivity with simultaneous fundus examination & correlation, thus testing both macular structure and function simultaneously at various points in macula. 3. Uses spectral OCT or SLO & Eye-tracker. Tip-192..... AZOOR (Acute Zonal Occult Outer Retinopathy) is a rare type of White dot syndrome (see Tip-180) that affects Outer Retina (photoreceptors-RPE) Zone-wise & Acutely with vision or field loss but only subtle (Occult) fundus findings initially. Etiology-? Autoimmune or viral. Commoner in young females. Presents with acute scotoma & photopsia. Abnormal ERG is characteristic. Treatment is ? Try steroids. Tip-193...... Typical Neuroretinitis is unilateral, idiopathic optic disc edema with macular star. Usually self limiting and non-recurrent. Treatment- empirical with systemic steroids/antibiotics. While DUSN (Diffuse unilateral subacute neuroretinitis) is caused by Nematode in young people. Look for worm, whitish subretinal spots & tracks with RPE mottling.
Treat by direct laser (to kill nematode, if located) or Albendazole with steroids. Tip-194.... Zaltrap is now being used off-label (1.25 mg in 0.05 ml) by retinologists as intravitreal anti-VEGF injection, as it is longer acting (bimonthly injection after 3 monthlies), costs much cheaper than Eylea & even Avastin ultimately & also more efficacious in some resistant CNVMs/DDME. Aflibercept (earlier called VEGF Trap-eye) molecule is FDA approved for eye use (as iso-osmolar Eylea/ 2mg in 0.05 ml injection vial) & colo-rectal cancer (as hyperosmolar Ziv-aflibercept/ Zaltrap 4ml vial of 25mg/ml). Both made by Regeneron Co., USA with different collaborators. Tip-195.... Increasing levels of Lipofuscin (wear & tear yellow-brown autofluorescent pigment of our body including eye) in RPE occurs not only with aging, but also in AMD & particularly Stargardt (causing „Silent‟ choroid on FFA -see Tip-142). Also seen in Cone & Best's dystrophy & Retinitis pigmentosa.
Tip-196.... Most consistent bad biomarker (on SD-OCT scan) most closely associated with poor visual acuity in DR, DME, CME, ERM & MacTel is 'Disorganisation of Retinal Inner Layers' (DRIL). DRIL is inability to differentiate boundaries of inner retinal layers viz. OPL, INL, IPL & GCL, because of ischemic damage to capillary plexuses. Persistence or improvement of DRIL with anti-VEGF also decides the visual prognosis. Tip-197.... Tips on Smartphone fundus photography- -Needs smartphone (with flash light coaxial with camera's lens), +20/28 D lens & optional camera App (e.g. FiLMiC Pro- paid app for iOS & Android, INR 1300/) to adjust exposure, zoom & light intensity. -Especially useful in tele-ophthalmology & emergency rooms. -Needs pupillary dilatation, clear media, continuous flash light & patient's cooperation. -Patient looks far with other eye, keep phone in video mode with flash on. -20D lens is kept 4-5cm (2") from eye (i.e. farther than in indirect ophthalmoscopy) & phone at ~20cm from lens.
-Retina seen only if camera, handheld lens & patient's pupil are aligned. -Image is inverted like in I/O. -For larger field, move 20D away from patient or phone towards the patient. Tip-198..... Senile changes in retina: -Decrease in photoreceptors -Decrease in melanin granules in RPE. -Increase in lipofuscin granules. -Basal laminar deposits form (sheet like deposits between RPE & Bruch's). -Decrease in choriocapillaris & choroidal flow. -Drusen form (between RPE & Bruch's), but not the large/soft ones. -Arteriosclerosis of retinal vessels. -Peripheral retinal degenerations increase e.g. Cystoid, Paving-stone & Lattice. Tip-199..... In diabetic retinopathy, retinal capillaries and venules are primarily affected, while Hypertensive retinopathy affects retinal arterioles primarily. Tip-200...... RPE Rip/tear is... -Sudden disruption of RPE in area of PED with scrolling on itself.
-Most commonly seen in AMD either naturally or after laser/Anti-VEGF injection. -Dreaded complication (like endophthalmitis) after Anti-VEGF inj. in AMD, causing sudden loss of vision, especially if fovea gets involved. -Risk factors include large PED in diameter & high PED (especially if >550mn) -OCT is best for confirmation of diagnosis & shows break in hyper-reflective RPE band with scrolled & wavy RPE in PED. -No known treatment for Rip, but AntiVEGF treatment for AMD can be continued. Tip-201..... Retinal break without SRF can be lasered (barraged) alone safely. With small SRF around retinal break, cryopexy alone is better & may suffice, without requiring full RD surgery. Tip-202.... Pneumatic retinopexy (intravitreal gas injection) may be tried in retinal detachment with single, superior break in phakes without any PVR. Patients with uncontrolled glaucoma or those who can't maintain posture for 5 days should be avoided.
Tip-203..... Hyperfluorescence (HF) on FFA is because of any of the 2 basic reasons: 1. Transmitted- HF starts in early phase but decreases in late phases. 2. Leakage- HF continues to increase in late phases. Leakage is called Pooling if HF occurs in predefined space & Staining, if HF is from scar/tissue. Tip-204.... In 2018, US FDA approved the first cloud based DL (Deep Learning) algorithm linked to the fundus camera, that could identify the eyes with diabetic retinopathy, that required referral to an ophthalmologist. DL is a type of Artificial intelligence based on computer neural network that analyzes a large data base & detects an outcome of interest. Tip-205...... Fuch's heterochromic iridocyclitis is the only chronic anterior uveitis, that doesn't form the posterior synechiae. Tip-206..... With +20D lens on I/O, one gets the ~50* field (For meaning of degree in retina, see Tip-11) & 3x magnification; while it is
~65*/2x with 30D. Working distance decreases with increasing power (2"/50 mm for 20D, 30mm for 30D). Panretinal 2.2 gives ~65*/2.7x & 40mm distance. Tip-207.... Hyper-reflective Dots (Foci)/HRDs on SDOCT unlike hard exudates in DR cause no shadowing. Also HRDs can occur in all retinal layers and disappear fast with antiVEGF or anti-inflammatory treatment. Tip-208..... Vitamin-D deficiency has been linked (empirical) to uveitis, ARMD, Thyroid eye disease, DR and dry eyes. Vitamin-D acts as anti-oxidant, scavenging free radicals. For Indians, half an hour of exposure of mid-day sun twice a week (without sunscreen) is sufficient to prevent Vitamin-D deficiency. Older people manufacture less of VitaminD. Vitamin-D3 (Cholecalciferol) is better than D2 (Ergocalciferol). Tip-209.... To simplify & predict the long term visual acuity after an eye injury, "Ocular trauma score" has been given that includes 6 presenting prognostic factors: Visual acuity,
Endophthalmitis, Globe rupture, Perforating injury, RD, RAPD. Tip-210...... On FFA, if leakage from retinal vascular endothelium is pronounced, cystoid spaces in CME may fill rapidly; while if leakage is small, cystoid spaces may fill very late in angiogram. Thus cystoid spaces continue to appear dark (hypofluorescent) in initial stages. Tip-211..... Cone dystrophy could be either stationary or progressive. Stationary variety has congenital/Infantile onset & causes pure cone dysfunction, while progressive variant starts later & also involves rods. Next Generation Sequencing (NGS) is the most advanced technique that helps to identify the defective genes in genetic disorders like Cone dystrophy. Tip-212..... In a case of Diabetic retinopathy, presence of disc edema and macular star usually indicates coexisting Hypertensive retinopathy.
Tip-213..... CMV retinitis is commoner in patients of HIV with CD4 (T- Helper cells) counts below 50 cells/mm3. Normal count is 500- 1500 cells/mm3. CMV retinitis is the most common opportunistic ocular infection in AIDS. Tip-214..... Aflibercept (Eylea) binds to all forms of VEGF-A with greater affinity than Bevaci & Ranibi-zumab. It also binds to VEGF-B & Placental growth factor. Tip-215..... In a case of unilateral retinitis pigmentosa like picture, always rule out DUSN (Diffuse unilateral subacute neuroretinitis)- caused by nematodes. Tip-216...... On USG-B Scan, in Choroidal melanoma, internal reflectivity is low while height to base ratio is high unlike Choroidal metastasis. Choroidal metastases are typically yellowish (amelanotic) elevated lesions with SRF & indicate widespread metastases and poor prognosis.
Tip-217..... Juvenile idiopathic arthritis/JIA (formerly called Juvenile rheumatoid arthritis/JRA) is the most common cause of uveitis in children (<16 years). Risk factors for developing uveitis in JIA include younger age of onset, girl, oligo-articular involvement & ANA positivity. Commonly asymptomatic with bilateral, non-granulomatous anterior uveitis & commonly causes cataract. Control with steroids/cycloplegics. Immunomodulators (e.g. MTX) tried if above fails. Tip-218...... Retinal whitening in Commotio retinae (blunt closed globe trauma) is due to disruption of photoreceptors' outer segments & not due to extra-cellular edema, as there is no breakdown of blood-retinal barrier & retinal blood vessels remain intact. Usually, self resolving in majority & steroids have a doubtful role. It is called Berlin's edema, if macula is involved. Tip-219...... Hard drusen (<63 mn, as per AREDS) fluoresce early on FFA (due to overlying RPE atrophy), while Soft drusen (>125 mn)
hyperfluoresce later. Soft drusen (see Tip62) form a risk factor for CNVM. To clinically judge the size of drusen, compare it with the width of Central retinal vein, which is also ~125mn. Tip-220..... In CRAO, BRAO, Cilio-retinal AO, sometimes embolus in artery may be visible, which could be.. 1. Fibrin-platelet embolus in majority of cases. Dull, grey-white & longer. These move faster (mobile) & may move spontaneously allowing vessel to open. Also these are frequently associated with amaurosis fugax. 2. Cholesterol/Hollenhorst plaque- shiny yellow embolus. 3. Calcific- large white plaque. Least common & are of cardiac origin. Emboli are of either carotid (mostly) or cardiac origin. Tip-221....... In a suspected retinal hole in retinal periphery, always rule out ABC i.e. A(e)nclosed oral bay, Blot hge & Cystoid degeneration. Indentation helps (see Tip-73). Tip-222..... White spots in retina:
1. Hard exudates- whitish-yellow, waxy, deeper (in OPL) than soft, distinct margins, no vitreous cells. 2. Soft exudates- whitish, superficial, feathery margins, no vitreous cells. 3. Drusen- round/oval, whitish/yellowish colour lesions. 4. White dot syndromes- are inflammatory chorioretinopathies. Always look for vitreous/retrolental cells. 5. Heredomacular dystrophies- bilateral & commonly symmetrical lesions (see Tip-96). 6. Etc. Tip-223.... Most common manifestation of drug toxicity (e.g. to CQ, HCQ, PTZ, etc.) to retina is in form of pigmentary maculopathy. Classical presentation (but not the earliest) is Bull's eye maculopathy with fovea surrounded by depigmented ring followed by ring of hyperpigmentation. Earliest clinical signs are non-specific and include loss of foveal reflex & macular mottling (RPE in different shades). FAF & Mf-ERG are most sensitive & can detect changes before the fundus changes develop. Tip-224........ Incidence of NVG is more in those cases of PDR who have undergone vitrectomy or
cataract extraction, as this leads to greater entry of vaso-proliferative factors into the anterior segment. NVG in diabetic retinopathy (DR) indicates poor systemic prognosis with >20% mortality rate. Tip-225.... CSR (CSC) is NOT the macular edema, as the fluid collection in macular edema is intraretinal (within the neurosensory retina/NSR), while it is subretinal (beneath NSR or RPE/SubRPE/PED) in CSR. Tip-226...... Always rule out the peripheral retinal capillary hemangioma (isolated or part of VHL syndrome) in a young patient with unexplained macular edema. Tip-227..... During normal retinal development, retinal vessels starting from optic nerve head reach nasal ora by 36 weeks & temporal ora by 40 weeks i.e. later. Tip-228..... In Purtscher (post-traumatic) & Purtscher like retinopathy (non-traumatic) (See Tip151), pathognomonic features are Purtscher flecken, which are retinal whitening patches
(looking like soft exudates) with uninvolved centrally running retinal vessels. Soft exudate unlike Purtscher flecken involves the RNFL only, while the latter extends deeper. However both indicate capillary occlusion. Flecken usually resolves in weeks to months and the treatment is of no proven value. Tip-229...... In CRAO (see Tip-132), Cherry red spot is due to axoplasmic stasis & swelling of ganglion cells which are absent in fovea, while Cattle-trucking (box-carring) is due to segmentation of blood column in retinal vessels. Both may take few hours to develop after CRAO. Tip-230.... In MacTel (PFT)/Macular telangiectasia on OCT, hyporeflective cystic spaces , looking like edema occur in outer retina (ONL), but there is no increase in retinal thickness; as there is no edema but rather loss of ONL & ellipsoid zone. Type-2 variant of MacTel is most common & is an acquired bilateral condition seen in middle aged with DM & HT as risk factors.
Tip-231...... AV nicking is the hallmark of chronic Hypertensive retinopathy. In this, retinal vein becomes less visible or even disappears on either side of artery at its crossing. Tip-232..... On OCT scan, hyper-reflectivity & increased thickness of inner retina indicates either acute inflammation or infarction (e.g. in acute CRAO) of retina. Tip-233.... Cone dystrophy is either1. Stationary- early onset (infantile) & has pure cone dysfunction. 2. Progressive- later onset & also involves rods. Molecular genetics (especially Next Generation Sequencing, NGS - available in India for INR 20,000/ & above) helps to exactly differentiate. Tip-234..... Intraoperative OCT in Eye/VR surgery: -SD-OCT built in the microscope itself i.e. microscope integrated (MIOCT). -Useful for transparent/very thin structures, not easily visible with microscope, thus useful for membrane (ERM, ILM, etc.)
peeling & lamellar corneal surgeries (e.g. DMEK). -Foot or assistant operated, providing real time OCT imaging. -Available from Haag-streit (iOCT), Zeiss, Leica (also hand- held), etc. -Now also integrated with 3D visualisation systems (see Tip-235). -Used by Neuro, ENT, vascular surgeons also. Tip-235.... 3D viewing in VR/AS surgery: -surgeon performs by not looking through eye pieces of microscope but on panel display (heads-up)- large HD monitor. -Either Active system (e.g. Sony HMS/ Head mounting system)- viewing by electronic glasses or Passive (e.g. Ngenuity/Alcon, Artevo 800/Zeiss & True vision)- viewing by 3D polarised glasses. -Provide better & higher: depth of focus, resolution, illumination, magnification & delineation. Also less backaches for surgeons (superior ergonomics). But less comfortable for assistant. -Great teaching tool, sharing same screen for whole watching team (assistant/teacher can opine better).
Tip-236.... Argus-II Retinal implant (prosthesis): -FDA approved for severe Retinitis pigmentosa (RP) (2013). -By US co. (Second sight medical products Inc.) -3 parts: Eye glass mounted camera, Video processing unit (VPU) & Stimulator (implanted on retinal surface i.e. epiretinal after vitrectomy). -Costs ~1.5 lakh US $ + surgical cost. -Especially useful in RP, because only photoreceptors damaged, while inner retinal layers with ganglion, bipolar, amacrine & horizontal cells remain intact. -Bionic vision means artificial, functional vision. -Other Retinal bionic implants includeAlpha-IMS (German), Prima (French), etc. Both use subretinal implants. -Maximum vision provided by any implant is 6/160. -For other blinding disorders (e.g. DR, Glaucoma, optic atrophy, etc.), direct cortical stimulation prosthesis are being tried. Tip-237...... Hard drusen have well defined borders, while Soft ones have ill-defined margins & have tendency to coalesce producing
drusenoid PED, which shows pooling on FFA with leak not extending beyond its margins. (See Tip-219) Tip-238… Acute Retinal Necrosis (ARN) & Progressive Outer Retinal Necrosis (PORN)..... -Together called "Necrotising herpetic retinopathy". -Majority by Varicella Zoster, less often by Herpes simplex. -ARN is basically acute retinal 'arteritis' causing retinal infarcts (well defined, whitish-yellow necrotic patches) with vitriitis. -Unlike ARN, PORN has NO vitriitis & occurs in Immunocompromised host with 'rapid' progression. -Diagnosis mainly clinical. Viral-PCR from aqueous/vitreous samples. -Prognosis- poor (>50% develop RD from necrosis). -Treatment- Antiherpetic (prevents bilaterality)- Systemic (oral/IV of Valacyclovir &/or I-Vit of Ganciclovir, with oral steroids after 1-2 days of anti-viral in ARN.
Tip-239.... During cataract surgery, aqueous commonly gets contaminated by surface bacteria but only rarely causes endophthalmitis, because of fast aqueous turnover (fully replaced within 2 hours); while bacteria introduced into the vitreous (e.g PC break, I-Vit injections) commonly results in endophthalmitis as vitreous has no regenerating power or turnover. Tip-240.... Always rule out Sarcoidosis in a case of panuveitis, if chorio-retinal lesions (hypopigmented) are more in inferior half of fundus. Tip-241.... Fundus photos in FAF, FFA & Red-free are black and white. In FAF, both retinal vessels & optic disc appear dark (see Tip-123); while on FFA both appear white. In Red-free fundus images, disc is white but blood vessels are black. Tip-242..... Swept Source OCTA (SS-OCTA) is now available commercially (e.g. Topcon). Advantages of (SS-OCTA) over SDOCTA.... 1. Higher wavelength (1050nm) (850 of SDOCTA), hence penetrates deeper through
RPE, picking type-1 CNVM better & visualising choroid better (earlier possible with ICGA only). 2. Faster scanning speed, allowing denser scan patterns & larger scanned areas (wider field- 12mm; 1mm~5*, see Tip-11) in a defined time. 3. Longer wavelength is safer for eye allowing higher laser power. 4. Media haze obstruction is less. Tip-243..... Anemic retinopathy occurs with low oxygen carrying capacity of blood (Hb <6 gm%). Causes hypoxia, thus affecting mainly superficial retinal layers causing superficial hemorrhages, soft exudates, retinal/macular edema & occasionally subhyaloid hemorrhage. Arteries are attenuated, while veins are dilated & tortuous. Treat the etiology & it resolves. The term 'Retinopathy' is used only for retinal diseases caused by systemic ailments & NOT for exclusive retinal diseases. Tip-244...... To diagnose peripheral retinal ischemia on ophthalmoscopy, look for sclerosed retinal vessels with dull greyish discoloration of peripheral fundus background.
Tip-245..... OCT uses low coherence interferometry light. Why low coherence? With low coherence (temporally), two path lengths of lights are very nearly the same i.e. within a micron or so. Thus in OCT, the low temporal coherence allows distances to be determined precisely down to the micron level, enabling high resolution (axial resolution of 1-10 micron) & high speed imaging. Resolution is much higher than USG (typically 1mm with 3 MHz probe, 0.3 mm with 10 MHz; higher resolution with higher frequency, but lower penetration), but approaching that of histopathological section. OCT is fibre-optic based, hence can be interfaced to many instruments like microscopes, endoscopes, catheters, etc. Tip-246..... In Eales' disease, retinal neovascularisation directly correlates with the extent of peripheral retinal ischemia. While NVD in many uveitis cases can occur without any ischemia; thus inflammation alone in many uveitis cases can trigger neovascularisation. Hence, it responds to steroids & immunosuppressives.
Anti-VEGFs help only partially in these cases, although VEGF remains the key element in these cases. Tip-247..... In Chronic CSR: -Silent type-1 CNV (sub-RPE) needs to be ruled out on multimodal imaging (Swept Source-OCTA is best as FFA & OCT commonly fail in these cases). - Definition: persistent symptoms of > 6 months or persistent SRF with RPE epitheliopathy (atrophy, hypertrophy or hyperplasia) & leakage on FFA. - CNV especially occurs in those chronic cases which show thinning of fovea, subRPE deposits causing flat irregular PED & increased choroidal thickness. Tip-248..... While bacterial culture detects only live organisms, PCR detects both dead & live bacteria without any differentiation. PCR needs just one or two organisms for detection unlike culture, thus PCR is much more sensitive than bacterial cultures. Tip-249...... In the definition of Posterior pole of retina (fundus), Fovea forms the central point with 2 disc diameters (DD) of radius (i.e. 3mm); while defining zones in ROP, optic disc's
centre is the central point (Zone-1 has 4DD radius). Tip-250..... Postoperative endophthalmitis (bacterial) usually starts after 24 hours, while postoperative sterile inflammation (e.g. TASS) starts within 24 hours of surgery. Tip-251..... The term 'Hot spot' in ICGA is used for any focal area (< 1DD area) of intense hyperfluorescence corresponding to neovascularisation. It has 3 patterns in AMD viz. Polypoidal CNV in majority, RAP & Focal occult CNV. Tip-252..... In PDR, NVE in majority occurs in the posterior pole (circle of 2 disc diameters radius with fovea as centre i.e. within temporal vascular arcade) itself. Tip-253.... Panuveitis is inflammation of all 3 uveal layers of any cause, while Endophthalmitis is Panuveitis caused by bacterial or fungal infection causing suppuration in vitreous or/and aqueous humour. Although bacteremia or fungemia from distant source can cause endophthalmitis,
endophthalmitis per se never acts as source of systemic infection. Tip-254..... Always trace the retinal detachment (RD) towards the ora on I/O. If RD is not extending till the ora, it is unlikely to be the rhegmatogenous RD. Tip-255...... Avoid PRP laser in PDR if there is: -severe glial proliferation or vitreoretinal traction (around temporal vascular arcade) ->60% of macular/paramacular areas not perfused -Florid surface neovascularisation -severe retinal edema -severe hypertensive or renal retinopathy. Tip-256..... In Near Infrared Reflectance (NIR) images, blood vessels and neovascularisation appear dark against fundus background because blood absorbs the infrared spectrum. Thus NIR imaging can be used to follow regression of neovascularisation noninvasively (without FFA). NIR also detects subretinal CNVM better.
Tip-257...... Advantages of Confocal Scanning Laser Ophthalmoscopy (CSLO) fundus imaging (e.g. Spectralis/Heidelberg & Optos) over conventional fundus camera imaging (see Tip-67): 1. Much higher contrast and resolution due to decreased/suppressed light scatter from background. 2. Single plane image acquisition at any desired plane possible (Enface/ transverse imaging). 3. Uses less light intensity, making the patient comfortable. 4. Non-mydriatic imaging possible with good quality images. 5. Detects even very low levels of fluorescence, making Fundus autofluorescence a great diagnostic tool. Tip-258..... Coats disease by definition is idiopathic retinal telangiectasia (arterial or venous) with intra/sub-retinal exudation (hard exudates, mainly cholesterol) but no vitreoretinal traction. Majority males & unilateral. Treatment: Observe, if minimal. Laser (less power, larger spots for longer duration) in multiple sittings to retinal vascular abnormalities (aneurysms or
telangiectasias). Laser take comes only if no or minimal SRF. Cryo, if SRF more. Anti-VEGFs also being tried. If exudation is secondary to other retinal diseases, it's called Coats' response. Tip-259...... Prolonged and chronic sun-gazing as in some religious practices can also cause Solar or Photic retinopathy (photochemical, free radical induced), damaging the 'outer' retinal layers in fovea. Milder cases may show no fundus findings clinically but may reveal focally disrupted sub-foveal RPE and outer retinal bands on SD-OCT. No treatment helps, but partial recovery possible. Tip-260...... Autoimmune retinopathy is a rare retinal disease in which auto-antibodies get formed against photoreceptors or bipolar cells. It can occur as part of para-neoplastic syndromes. Fundus changes are non-specific retinal vascular attenuation and RPE/retinal atrophy but NO signs of retinal inflammation. Treatment is systemic steroids. Tip-261.....
In exudative stage of hypertensive retinopathy (HTR) with extensive disc edema, retinal & macular edema with ischemia is because of breakdown of bloodretinal barrier with damage to vessel walls. Most important treatment of HTR is control of BP. However, if changes don't resolve inspite of good systemic control of BP, Intravitreal Anti-VEGF injection may be tried. Tip-262..... Bear tracks in peripheral retina are a type of grouped Congenital hypertrophy of retinal pigment epithelium (CHRPE) seen as flat, well-demarcated, hyperpigmented deep retinal lesions. These are of no clinical significance except to differentiate from similar looking spots in Gardner's syndrome (Colo-rectal polyposis with extremely high incidence of colon carcinoma). Lesions in Gardner's syndrome are 'oval' with variable pigment & comet-tail appearance. Tip-263....... On USG B-Scan, rhegmatogenous RD unlike PVD shows/is: -always attached to optic disc & is thicker. -100% spike on A-scan (compared with scleral spike).
-presence ot second membrane confirms it to be RD. -not so free movements on kinetic scan. -not smooth generally, but has some folds. Tip-264..... Patients with moderate hypertensive retinopathy with retinal hemorrhages, soft exudates & microaneurysms have strong association with stroke, renal dysfunction & cardiovascular mortality. Tip-265..... In Retinitis pigmentosa (RP), changes in full-field ERG (reduction in a & b-wave amplitudes) commonly occur before the clinical symptoms & retinal changes appear. High doses of Vitamin-A palmitate (15,000 IU/day, beware of hepatotoxicity) with Lutein (12mg/day) & Omega-3 fatty acid (Docosahexaenoic acid/DHA, diet rich in oily fish) might delay progression of RP. Autosomal dominant RP variant has best prognosis, while X-linked variant has worst. Tip-266...... OCTA can detect neovascular complexes even in dry looking (non-exudative) cases of AMD, which are otherwise missed on FFA or OCT.
Tip-267...... Anti-phospholipid syndrome (APS) is an autoimmune disorder directed against body tissues containing phospholipids including those of eyes (mainly retina). Thrombosis related complications occur. APS must be considered in every case of thrombo-embolic disorder of eye especially if no other risk factor is present. Get Lupus anticoagulant, anti-cardiolipin & anti-beta 2 glycoprotein antibodies. Long term anticoagulation is required. Tip-268..... Epiretinal membrane (ERM) is avascular, fibrocellular membrane with contractile properties and is formed by glial cells (from fibrous astrocytes in INL or from RPE after retinal break). PVD predisposes to it by causing full thickness retinal break or breaks in ILM. Persistent metamorphopsia after ERM peeling is due to its incomplete peeling, while poor vision gain postoperatively is due to long standing macular edema. Tip-269..... Susvimo (from Genentech/Roche group) ocular implant, releases 100mg/ml of
Ranibizumab continuously over 6 months, was approved by FDA in October'21 for wet AMD. Prerequisite before injection- patient must have responded to at least 2 previous antiVEGF injections. Higher endophthalmitis incidence (2%) was reported (conjunctival retraction). Tip-270....... On SD-OCT scan, Ethambutol primarily affects ganglionic cell layer (inner retina) while Ellipsoid layer (outer retina) is primarily affected in HCQ (Hydroxychloroquine) toxicity. Diagnosis of ETM toxicity is mainly clinical (VA, fields, CV, fundus, Amsler grid). To detect subclinical toxicity: VEP, OCT & mf-ERG may be useful (but not always). For HCQ toxicity- For preclinical detection, earliest changes are seen on OCT (disrupted Ellipsoid zone). On visual fields (paracentral scotoma in 10-2), on FAF (early central hyper-autofluorescence) & on mfERG (central depression). Tip-271...... PVD (partial/complete) is the prerequisite for any retinal break or detachment.
Tip-272..... Choroidal detachment (CD) if has associated low IOP is always serous, while hemorrhagic CD (PCA rupture) always has high IOP. Hemorrhagic CD if occurs per or postoperatively causes severe, sudden onset pain despite adequate analgesia. Serous CD is always painless. Tip-273...... FDA has approved Faricimab (Vabysmo/ Genentech of Roche group) - Anti-VEGF drug for wet AMD & DME in January'22. After initial 4 loading monthly doses, repeat injection required only after 2-4 months interval. Tip-274..... Retained intraocular foreign bodies (RIOFB) that remain inert include those of glass, porcelain, carbon, silver, gold and platinum. Tip-275..... In Stargardt's disease unlike Cone-rod dystrophy, ERG (full-field) is commonly normal in early stages. Tip-276..... Even a single soft exudate found on fundus examination in an otherwise healthy,
asymptomatic individual must not be ignored, as it usually indicates a serious underlying systemic ailment (see Tip-94). The most common cause is diabetic retinopathy followed by hypertensive retinopathy (DBP of >110 mmHg). 50% of AIDS patients will show soft exudates in fundus. Soft exudate (RNFL infarct) usually takes approximately 6 weeks to resolve. Tip-277..... Always suspect CNVM in a case of chronic CSR showing flat & irregular PEDs, where OCTA is especially useful for detection of CNVM. Tip-278..... Signs of massive choroidal hemorrhage (expulsive hge) during intraocular surgery include: Anterior chamber shallowing with iris prolapse followed by loss of red reflex and dark mound moving forward pushing vitreous and lens forward with tensing eyeball. Tip-279...... Patients with degeneration or dysfunction of cones become highly photophobic in which darkly tinted glasses can help. Photophobia
may start even before any clinical signs appear making it appear malingering. Tip-280...... Vitreous hemorrhage in Eales' disease occurs not only due to neovascularisation, but can also occur due to vasculitis per se. Tip-281...... In DDME (Diffuse diabetic macular edema), some retinologists prefer Intravitreal Ozurdex (see Tip-79) as first line therapy if the patient is pseudphakic or has to undergo cataract surgery soon. It's effect lasts for ~3 months. Avoid Multifocal IOLs in DME (or any maculopathy). Use steroids & NSAIDs for longer time (double) in DME patients undergoing cataract surgery to minimize the inflammation. Tip-282...... Diabetic Retinopathy Clinical Research Network (DRCR.net) (now called DRCR Retina Network) was started in 2002 (collaboration of NEI & National institute of Diabetes & Digestive & Kidney diseases, USA) for multicentric research & trials in
DR. Now research on ARMD, ROP, etc. has also been included. Protocol-I proved benefit of anti-VEGF in DME. Tip-283...... During PRP laser, it is easier to cover upper half of retina than the lower, as it is easier for the patient to look up than down. Hence laser the inferior retina first to have patient's greater cooperation. Moreover, vitreous hemorrhage in proliferative retinopathy anytime can make covering inferior retina difficult. Tip-284.... There is NO direct correlation (only rough) between visual acuity and Central macular thickness on OCT in macular edemas especially in DME (Diabetic). Look for other prognostic biomarkers on OCT in DME (see Tip-78). Patients with largely broken FAZ on FFA & those with large lipid deposits in fovea will have poor visual acuity regardless of macular thickness. Tip-285...... One of the disadvantages of PASCAL laser (single shot of predetermined pattern/array of multiple laser spots) for retina is that same power is delivered for all the laser
spots in single shot, while retinal thickness varies with area. Retinal thickness decreases as we move peripherally requiring less laser power Tip-286.... To assess Flare/Cells in anterior chamber in anterior uveitis, always assess it before instilling fluorescein dye for corneal staining, as its diffusion into anterior chamber interferes in interpretation. Tip-287..... Peripheral exudative hemorrhagic chorioretinopathy (PEHCR) is a rare senile (>70 years of age) peripheral retinal degeneration mimicking ARMD (earlier considered Peripheral ARMD, but No drusen) or even melanoma. Commonly self-limiting or self-resolving. Hypertension is the common association. Causes subretinal or sub-RPE hemorrhage/fluid in peripheral retina (i.e. between equator & ora, usually 'inferotemporally') with exudation, vitreous hemorrhage. Exudates may invade macula. Tip-288...... Although chronic CSR/CSC (unresolved for over 3 months) has no definite proven
treatment, Eplerenone (25-50mg OD for 3 months) is now being commonly used for it. Patients with widespread RPE changes are poor candidates for resolution with Eplerenone. Eplerenone is aldosterone receptor antagonist commonly used in heart failure & resistant HT. Eplerenone has less sex hormone related side effects as compared to spironolactone. PDT in chronic CSR is useful only if the choroid is thick Treatment- Observe, if asymptomatic. AntiVEGF, Laser/Cryo may help. Tip-289....... 'Leopard skin (spots) pattern' is morphological description of fundal lesions, which can occur in many diseases like leukaemia, lymphoma, metastatic carcinoma, Uveal effusion syndrome, etc. Best seen on FFA. Basically occurs due to fibrosis or hyperplastic changes of RPE in periphery of lesions while thinning and atrophy of RPE occurs centrally.
Tip-290...... Always think of CHRRPE (Combined hamartoma of retina and RPE) in young children with ERM. 'Omega sign' on OCT is characteristic, showing ERM with secondary retinal folds (tractional). CHRRPE is a congenital hamartoma (benign mix-up of local healthy tissues- retinal & RPE) of young children. Lesion is elevated, juxtapapillary and develops prominent vascular corkscrewing due to vitreoretinal fibrosis and ERM. Tip-291..... Saxena Retinal Grid.... Model 520 is used with +20D indirect ophthalmoscopy lens & model 428 for +28D lens from Ocular Instruments, USA. -is used for measuring size of fundal lesions, optic disc & ROP evaluations. -has square grids of 4mm each (for 28D lens) & 5.2 mm spacing (for 20D lens). -Grid fits onto the front side of the lens. Tip-292....... Blue light (400-470 nm) filtering by chromophores in intraocular lenses & spectacle lenses are not definitely proven to prevent AMD & macular phototoxicity.
Tip-293....... After Intravitreal injection, patients often complain of floaters for 2-3 days, because of air bubbles. Always warn them before hand. Tip-294..... Doses of Intravitreal Anti-VEGF injections (All in 0.05 ml): 1. Bevacizumab- 1.25 mg 2. Ranibizumab- 0.5 mg 3. Aflibercept (Eylea)- 2 mg 4. Brolucizumab- 6 mg 5. Faricimab (Vabysmo)- 6 mg Tip-295....... Factors that delay the progression of diabetic retinopathy (DR) include: 1. Complete PVD In the following factors, reduced metabolic & oxygen demand with or without chorioretinal thinning is responsible. 2. Pathological myopia 3. Choroidal coloboma 4. R.P. 5. Healed extensive chorioretinitis 6. Optic atrophy (loss of RNFL reduces oxygen demand) 7. Amblyopia (again reduced retinal oxygen demand responsible).
Cataract surgery sometimes hastens the progression of DR by breaking blood-retinal barrier & causing inflammation. Tip-296....... To look through smaller pupils, newer designs of indirect ophthalmoscopy lenses (of similar power), which have steeper anterior (front) surface allowing easier view of fundus in smaller pupils (e.g. from Katena, NJ, USA) are now available. Tip-297....... Comparing Anti-VEGFs in retinal diseases (in brief).... 1. Avastin/A. (Bevacizumab) is used offlabel. Multidose vial with Compounding concerns. Efficacy same as of Lucentis/L. (Ranibizumab) as per CATT study. A. has longer half life in systemic circulation (more likely thrombo-embolic events & stroke). L. is a smaller molecule, hence penetrates retina better & has higher affinity for VEGF-A than A. 2. As per Protocol-T of DRCR.net in DME, A., L. & Eylea (E.) are equally efficacious, if DME is milder with BCVA of 6/12 or more. However, E. is better if BCVA is 6/18 or worse. 3. L. is the first Anti-VEGF to be approved for ROP. E. not yet.
4. E. better for PCV than others. Combined with PDT /EVEREST-II. 5. Brolucizumab (available as Pagenax in India for ~INR 25000/. FDA approved for ARMD & DME & is longer acting. Given every 3 monthly after 3 monthly loading doses. E. is given bimonthly. 6. Faricimab (Vabysmo) not yet marketed in India. Injected every 2-4 months after 4 initial loading doses. (See Tip-273 & 294). 7. Ranibizumab ocular implant (Susvimo)- for sustained release. See Tip- 269. Tip-298..... Inferotemporal quadrant is the most preferred site for Intravitreal injections because of: 1. Easy accessibility 2. Patient's tendency to squeeze and roll up the eyes due to Bell's phenomenon. Tip-299....... Larger non-perfused retinal vessels are seen as ghost vessels on ophthalmoscopy, while smaller or deeper non-perfused vessels can't be visualised on ophthalmoscopy. FFA can visualise only the perfused superficial retinal vessels. Deep capillary plexus is seen on OCTA but not on FFA.
OCTA can find these deeper retinal ghost vessels indirectly by showing these as avascular areas , while ghost vessels are directly seen on en-face OCT. Tip-300...... +30D lens is preferable over 20D for indirect ophthalmoscopy (IO), if: 1. Panoramic fundal view required 2. Patient not co-operative (e.g children) or when quicker procedure is required. 3. Non-fixating eyes e.g. in Nystagmus. 4. Scleral indentation is required. With 30D lens, working distance from cornea is less than with 20D. Use 16D lens, if better disc or macular evaluation is required and patient can't sit for slit-lamp examination. Tip-301..... International Classification of Retinopathy of Prematurity-3 (ICROP3) is the 3rd edition of ROP classification (2021). Major changes from previous edition are newly introduced definitions (although SEZ i.e. Severity/Stage, Extent & Zones are the same): 1. Posterior zone-II- is 2DD posterior concentric zone around zone-I. 2. Notch- is ROP lesion entering into more posterior zone for 1-2 clock hours.