antibodies (derived from a single B-cell clone) Depending upon the source of mAb, WHO has given uniform generic nomenclature (2009).... -Zu... Humanized i.e. Ab generated from genome of non-human species, modified to produce matching natural human antibodies. -Xi... Chimeric (animal) origin -U... Human source of genome (injected into mice to produce Ab) -O... Murine (mice) source Tip-73..... Tips for Indirect Ophthalmoscopy (I/O)..... -Use minimum usable light & start with superior periphery (let patient acclimatise to light). -Use small spot size for small pupil & vice versa. -Remember, although image we see in the lens is laterally & vertically inverted eg if seeing superiorly, image of peripheral retina is seen inferiorly in the field of the lens. But clock hour of retina remains the same eg patient looking superiorly means superior retina only is being examined. -Hold the patient‟s hand (proprioception) or tap on his face to describe the direction, patient has to look at. Verbal commands may confuse him.
-If nose is obstructing, while seeing from side, turn his head towards yourself. -To look at the periphery, turn your head by 45* on one side. -For Scleral depression, don‟t ask patient to look in extreme gazes, only slight eye turning is enough. Tip-74....... Macular Telangiectasia (MacTel) could be Juxta (central 1.5 mm of Anatomical Macula), Parafoveal/PFT (1.5-2.5 mm) or Perifoveal (2.5-5.5 mm) Telangiectasia of Macular capillaries. Type -2 MacTel is commoner variety (type1 is U/L & congenital, males exclusively, Coats‟ variant) of an uncommon disease. Features... -B/L, after 50, Associated DM/abnormal GTT or HT common. -Always think of MacTel, if on fundus exam, one notices grayish discolouration (better seen in red- free photo) around fovea (temporally usually) of BE. Asymptomatic usually. -Telangiectatic capillaries seen diving into deeper retina at right angle, which may cause Subretinal neovascularisation (SRNVM) (in 5%) (CNVM of RETINAL origin & not choroidal) -FAF detects it earliest with loss of masking
in foveal region (lutein pigment loss). -FFA- characteristic intraretinal dye leakage in temporal macula, but NO macular thickening on OCT (rather foveal atrophy/thinning). -Treatment- None effective usually except Anti-VEGF for Neovascularisation, if present. Tip-75..... Endogenous Endophthalmitis (EE)..... -Always consider if severe anterior uveitis is not responding to steroids. -Look for Infected focus (hematogenous spread) (culture accordingly) & Immunocompromised host. -In Indian context, Gram -ve & fungi are commoner (Gram +ve in west) -Uncommon (5% of all Endoph). -Classified into- Focal or Diffuse & Anterior or Posterior -Unlike Postop Endophthalmitis, Systemic antibiotics are must (effective for both systemic & Ocular manifestations). Endophthalmitis Vitrectomy Study (EVS) recommendations don‟t apply here. -Give antibiotics as per c/s or broad spectrum- IV Vanco + Amika/Ceftazidime. Also give them Intravitreally (see Tip-50). Topical Atropine & steroids also, if fungal not suspected.
-For suspected/proven fungal, give IV Voriconazole (400mg BD x 1day as loading dose, then 200mg BD). Also Intravitreal Voriconazole (50 microgm in 0.05ml). Alternatively, use IV & IVit AmphotericinB. -Severe or non-responding cases also need early PPV. Tip-76..... Many retina specialists are now following the „Treat & Extend‟ regimen instead of PRN (Pro Re Nata)/ Treat & Observe for treating wet AMD with Anti-VEGFs. In this, after a course of 3 injections, IVit is repeated till the macula is dry; thereafter one keeps extending the interval between 2 injections (but one keeps giving the injections), depending upon the response. While in PRN strategy, after the course, inject till the macula is dry & thereafter repeat injection only if required. Tip-77...... For Prophylactic Cryopexy of large retinal tear in peripheral retina, place multiple cryospots around the tear (~2mm whitening around entire tear) & NOT directly beneath the break, as it releases more RPE cells causing macular pucker & PVR.
Tip-78...... Poor prognostic Biomarkers for Diabetic retinopathy (DR) on SD-OCT scan.... -Disrupted Ellipsoid zone (EZ), earlier called Inner/Outer segment junction (hyperreflective layer between 2 hyper-reflective layers of RPE & ELM in outer retina, Tip23), if damaged, is the most important poor prognostic biomarker. EZ disruption is also a poor prognostic marker for AMD, CSC & RVOs. -Presence of Hyper-reflective dots (HRDs) of 20-40 mn size in all retinal layers. Represent lipid exudation & clustered microglia (Immune cells/macrophages within retina). HRDs in fovea especially indicate poor prognosis. -Disorganisation of Retinal Inner Layers (DRIL)- Boundaries between GCL/IPL & INL/OPL, if lost in >50% of central 1mm zone of Fovea. -Outer retinal tubules (ORT)- See Tip-44. -Presence of ERM, VMA & VMT. Tip-79..... OZURDEX Implant..... -0.7 mg (700mcg) Biodegradable, Intravitreal Dexamethasone implant. -US-FDA approved it for... 1. Macular edema (ME) (2009) following BRVO & CRVO.
2. Non-infectious posterior uveitis (2010) 3. Diabetic ME (2014) -Therapeutic effect for 3-6 months. Readminister after 3 months. -Contraindicated in Infectious uveitis, glaucoma & any infection in & around the eye. -In centre involving DME, generally reserved for patients unresponsive to AntiVEGFs. May be considered first choice in pseudophakes. -Now available in 23 G injector -Dexa is less lipophilic than Triamcinolone & Flucinolone (Retisert,B&L & Iluvien), hence accumulates less in Trabecular meshwork & lens. IOP rise is thus less likely (>10mmHg in 15%, peaking at 8 weeks). -Cost is 26-28k -Given like any other IVit injection (but needs higher force, thicker gauge) or Trocarcannula insertion. -Procedure- Remove Tab straight up. Enter at 30* angle on sclera with bevel up & then perpendicular. Insert till sleeve of needle. Press Actuator FULLY (audible click heard) to inject 6mm rod shaped white implant. Tip-80..... Common Peripheral retinal degenerations.... Basically in 3 locations... 1. Vitreoretinal- Lattice, WWP & WWOP.
2. Intraretinal- Microcystoid, Retinoschisis (see Tip-81), Pars plana cysts. 3. Retino-choroidal- Paving stone. None of these per se need any prophylactic treatment except occasionally in Lattice (see Tip-59) & Retinoschisis (see Tip-81). Tip-81...... RETINOSCHISIS (RS)..... -2 types- Congenital (Rare, X-linked juvenile) & Acquired (Senile/ degenerative). -Basically splitting of NSR, typically at OPL (at RNFL in Reticular) like Microcystoid degeneration. -Mostly accidentally found on I/O -Unlike RD, RS is/has... Mostly inferotemporal & B/L Shallow Immobile Smooth surface (no corrugations) Sharply defined margins Causes absolute scotoma No RPE mottling No Shaffer‟s sign (RPE cells in anterior vitreous) No retinal break or Demarcation lines On OCT- break in OPL but no detachment from RPE. Laser produces white burn in outer retina. -Treatment- NIL usually (no laser or
surgery), even if cataract surgery planned. Extremely rarely causes rhegmatogenous RD if breaks in both inner & outer laminae. Tip-82..... Pseudophakic CME (Post cataract extraction)...... -Intracellular fluid in Henle‟s OPL (watershed zone between retinal & choroidal circulation). -Important to RULE out missed CNVM of ARMD & DME (Tip-17). -Typically between 5-10 weeks postop with c/o blurring, decreased contrast sensitivity or colour desaturation. -More likely with PCR & vitreous loss -On +90D exam, (Red free/green light better)- dull FR (if CMT >300 mcn) -FFA- Asymptomatic, angiographic CME (in >60%) needs no treatment. FAZ intact. Petalloid leak in late phase is characteristic. If associated optic disc leak (Irvine Gass, inflammatory) present, rules out DME. No leak in CME with VMT. -OCT best for monitoring -Most cases resolve within 3-6 months. -Treatment... No standard treatment (No large scale studies available). Best treatment is topical corticosteroids with NSAIDs for 6-12 weeks. Also most
effective in prevention. Periocular steroids (20 mg post subtenon Triamcinolone) & IVit AntiVEGF in nonresolving cases. -YAG vitreolysis or PPV for VMT. Tip-83..... Lexicon used to describe lesions in posterior segment investigations... -USG-B Scan- Echogenicity (Echogenic/Echolucent) & Internal reflectivity of lesion. -USG-A Scan-Reflectivity (Hyper/Hypo) -FFA- Fluorescence (Hyper/Hypo) -OCT- Reflectivity (Hyper/Hypo) -ICG- Cyanescence (Hyper/Hypo) -FAF- Autofuorescence- (Hyper/Hypo/Iso) Tip-84..... Before considering AMD in relatively younger patient (40-50 years of age), rule out masquerading diseases like Chronic CSC/CSR & Pattern dystrophies (PD). PD is/has.... -No associated colloids or CNVM (very rarely CNVM may develop) unlike AMD. -Very slowly progressive & have much better prognosis than AMD. -Autosomal dominant, B/L, macular diseases forming various patterns of pigment deposition because of RPE disorder.
-Includes Adult vitelliform, Butterfly, Reticular dystrophies, etc. Tip-85...... Vitreomacular Adhesion (VMA) unlike Vitreomacular Traction (VMT) (SD-OCT based International classification of 2013) is/has... -NO change in retinal surface contour. -Asymptomatic (No metamorphopsia or d/v) -Needs no intervention (VMT needs surgery if VA is 6/18 or less). -Has associated partial PVD. VMA is called Focal if <1.5mm & Diffuse if >1.5mm. Tip-86….. SHUNT (Optociliary) vessels over disc..... -are collaterals formed between retinal (CRA) & ciliary circulations (SPCA). -Found in CRVO (most common cause), chronic glaucoma, chronic papilledema, & Optic N. sheath meningioma. -Unlike NVD, shunt has.... 1. Larger caliber (NVD has lacy, irregular appearance) 2. Never elevated over disc surface. 3. Starts & ends on disc itself. 4. Never leaks on FFA.
Tip-87....... Subretinal Hyper-reflective Material (SHRM) deposits (beneath NSR) on SDOCT scan -are an important morphological Biomarkers indicating poor visual prognosis in n-AMD & CSR/CSC. -are composed of fibrin, blood, neovascular complex or shed photoreceptors. -May lead to subretinal fibrosis (scarring) especially if ELM is involved. -In CSC, especially seen in those on long term steroids use, pregnancy or severe cases. Tip-88..... RETINAL HEMORRHAGES can occur at 6 different levels viz....... 1. Subhyaloid- Between posterior hyaloid & ILM is truly preretinal (Boat-shaped) as in Valsalva retinopathy. 2. Sub-ILM- Between ILM & RNFL is actually intra & not preretinal (See Tip-53). Usually clubbed with Subhyaloid as Preretinal. 3. Flame shaped hemorrhages- occur within RNFL eg in HT, RVO, Leukaemia & Anemia. 4. Dot & blot- Between INL & OPL eg in DR, MacTel & OIS. 5. Subretinal- Beneath NSR. Has amorphous (unclear boundaries) shape eg in Type-2 CNVM (Classical) of Idiopathic or Myopic.
6. Sub-RPE- Beneath RPE. Has well defined boundaries (RPEs‟ tight junctions) eg in Type-1 CNVM (occult) of AMD & PCV. Tip-89..... CRAO is mostly of atherosclerotic origin (thrombus at lamina cribrosa), while BRAO is mostly from embolus proximally anywhere. Tip-90..... Toxic Anterior Segment Syndrome (TASS) unlike Postop Infective Endophthalmitis is/has... -acute sterile postop anterior chamber inflammation. -Early onset (within 12-24 hours) -No pain -Limbus to limbus corneal edema -Raised IOP -No vitreous inflammation -Cause- Endotoxin or chemical mediated -Fast response to topical steroids (Pred acetate 1 hourly). Tip-91..... Always warn the patient undergoing PRP laser for Diabetic retinopathy about...... 1. No improvement in vision expected. 2. May worsen macular edema with deterioration of visual acuity. Always give
IVit Anti-VEGF first. 3. Possible loss of peripheral, colour & night vision. 4. May need supplementation. 5. May not succeed in regressing neovascularisation & patient may rebleed. Tip-92..... As per DRS, PRP for PDR is to be given only for HRC-PDR cases (NVD or NVE with vitreous hge; NVD >1/4 disc area). However practically, most retina specialists have been doing PRP for Non-HRC PDR cases also in following situations... 1. Patient not likely to follow up regularly 2. Pregnancy 3. Other eye lost to PDR 4. One eyed 5. Those to undergo cataract extraction soon 6. Associated NVI Tip-93….. On FFA, to differentiate Staining from Leakage (eg of scar, sclera, etc.), always see coloured fundus photo. In staining, dye (ie hyperfluorescence) does not extend beyond margins of scar unlike leakage. Tip-94…... Majority of patients with soft exudates, if DR & RVOs are excluded, will have some
serious systemic disease eg severe HTR, collagen diseases (SLE), GCA, Embolisms (carotid/cardiac), OIS, HIV, Leukaemia, anemia, etc. Don‟t confuse it with lesions of retinitis (Toxoplasmosis & CMV) & White dot syndromes. Tip-95…. PHOTIC MACULOPATHY..... -can occur due to Laser (visible or invisible wavelengths), Solar or Arc welding or even Microscope light. -Typically damages outer retina & RPE (persistent defect) -Basically photochemical damage (free radical generation) -Blue light especially dangerous (absorbed maximally by macular xanthophyll & RPE‟s melanin) -Damage depends on power, duration of exposure & distance of striking. -Lasers divided into 4 classes (1-4). Classes 1-3 further subdivided into 2 subtypes each differently by ANSI (American National Std Institute) & IEC (International Electrotechnical Commission). - Class 1 is in microwatts, Class 2 is upto 1 milliwatt. Class 1&2 are harmless to eyes unless focussed by optical instruments. -Class 3R is 1-5 mW (safe to eyes if
carefully handled & 3M is 5-500 mW (hazardous if exposed directly but not to diffuse scatter) Class 4 is >500 mW (hazardous to eyes & skin even if diffuse). -Photic maculopathy has no cure & recovers only partially. Tip-96....... Drusen of Familial dominant drusen unlike Flecks of Fundus flavimaculatus (Stargardt‟s disease) are sharply defined, whiter & roundish spots. White dots in Fundus albipunctatus are very uniformly distributed throughout the retina & NOT clustered unlike drusen. Tip-97....... Most common manifestation of OCULAR SARCOIDOSIS (OS) is bilateral granulomatous anterior uveitis (sometimes non-granulomatous also). -OS affects retina (vasculitis/candle wax drippings), choroid & Vitreous. -Rule out TB, Multifocal choroiditis, VKH & Intraocular lymphomas. -Diagnosis of OS although mainly clinical, International diagnostic criteria (2017) for OS should be followed.... ….Definite OS- Tissue biopsy proven (noncaseating granuloma from any body tissue) with Compatible uveitis.
.....Presumed- Biopsy negative, B/L hilar lymphadenopathy with any 2 out of 7 classical intraocular signs. .....Probable- Biopsy not done, No hilar lymphadenopathy but 3 intraocular signs present & 2 investigations positive (raised ACE, Lysozyme, ESR, CRP, negative Mx, etc.) Tip-98....... Always consider TB & Sarcoidosis in every case of granulomatous uveitis, Intermediate uveitis & Choroidal granulomatous nodules. Tip-99....... Branch Retinal Vein Occlusion (BRVO)... -usually occurs at AV crossings (superotemporally), elsewhere in inflammatory causes eg Eales & Sarcoidosis. -Newly added risk factors include Hyperhomocystenemia & Anti-cardiolipin antibodies (Thrombophilic states). -Vision affected only if macula involved by edema, hge, exudate or ischemia. -Peripheral or nasal BRVO may remain asymptomatic for months & may present as vitreous haemorrhage for the first time. -Do OCT for macular edema & give repeated AntiVEGF or Ozurdex (second choice). Later, Sectoral Laser is done if
neovascularisation present or FFA (done after 3 months) shows >5 DD areas of ischemia. -Damaged Ellipsoid zone on SD-OCT (due to chronic macular edema) is a poor prognostic Biomarker in BRVO also. Tip-100....... Practical considerations while giving systemic Corticosteroid (CSd) therapy..... -Diurnal cycle is best mimicked by giving CSd as single morning dose after breakfast. -Always add Proton pump inhibitor 1 hour before breakfast. -Tapering required only if CSd given for >1 week. -Alternate day therapy on long term use minimises Cushingoid side effects, but not osteoporosis, etc. -Rule out Koch‟s & DM. -Dosage has to be increased during acute stress situations. -Advise patient to do regular muscle exercises (avoids muscle wasting), take low sodium & potassium rich diet, avoid pregnancy, look for mood changes, always inform other treating physicians about treatment & regularly follow up with internist & always carry the medical card for an emergency. -Common side effects include osteoporosis
(give Ca & Vit-D supplements), peptic ulcer, myopathy, mood changes, cataract (unlikely with <10mg/day of Prednisone for <1 year), HT, DM, Menstrual problems, growth retardation & superinfections. -Switch to Immunosuppressives, if prolonged maintenance dose of >10mg/day of Predni required. -Deflazecort has fewer side effects on growth & osteoporosis. 5mg of Prednisone (prodrug of Prednisolone) or Prednisolone ~6mg of Deflazecort ~ 4mg of Methylprednisolone (less mineralocorticoid activity). Tip-101.... About PARACENTRAL ACUTE MIDDLE MACULOPATHY (PAMM)... -Forms an important differential diagnosis (D/D) of unexplained visual loss in adults. -Newly diagnosed entity on SD-OCT (2013) -Patient complains of sudden onset Negative paracentral scotoma -Ischemic origin (intra-retinal infarct) -Fundus- subtle greyish patches in macula -Hyper-reflective band at INL of retina (Middle layers & NOT outer retina) on SDOCT is pathognomonic. -Self limiting with partial recovery in weeks. No known treatment (treat ischemic risk factors).
-Important d/d with similar lesions is Acute Macular Neuroretinopathy (AMN) of younger people involving OUTER retina (OPL & ONL) with damage to Ellipsoid zone. Tip-102.... D/D of Angioid streaks are Choroidal rupture & Lacquer cracks (Pathological myopia): Angioid streaks radiate from disc, are linear & more often B/L. Choroidal rupture is U/L & mostly concentric to optic disc. Lacquer cracks are also usually B/L, concentric to disc & are associated with other signs of pathological myopia (posterior staphyloma with tilted disc & scleral crescent). Tip-103.... Bleb associated Endophthalmitis (BAE).... -May present months to years after trab. -Bleb becomes white (purulent), while in conjunctivitis, it looks RED only. -If infection from bleb (Blebitis) extends into posterior segment, it becomes endophthalmitis causing pain, redness & visual loss. -Any endoph in patient with bleb is BAE unless proven otherwise.
-More often associated with Streptococci, Hemophilus & Gram negative organisms, hence more severe. -EVS does not apply here. -Needs early aggressive treatment with Pars plana vitrectomy (PPV) & Intravitreal (IVit) Vanco & Cefta/Amika. Tip-104...... Always think of Masquerading Uveitis if idiopathic posterior uveitis after initially responding to steroids, fails to respond thereafter. Also consider it in older patients (>50 years age) presenting with uveitis for the first time in their lifetime. Most common cause is Primary intraocular lymphoma followed by leukaemia, systemic malignancies, IOFB, Ocular ischemic syndrome (OIS) & retinoblastoma, etc. Vitreous biopsy is the most important investigation for lymphoma. Tip-105...... There is no need for any Lab investigation in a case of first attack of acute anterior nongranulomatous uveitis. Cases of post-traumatic, Fuch‟s heterochromic, Behcet‟s, Sympathetic ophthalmia & VKH are the clinical diagnosis & don‟t need any lab investigations.
Tip-106....... Old patient (>50 years) complaining of dull ache around eye & having NVI, always think of Ocular ischemic syndrome (OIS). -Occurs due to atherosclerotic blockage of carotid or ophthalmic artery. -Narrowed retinal arteries, dilated veins (but NOT tortuous unlike CRVO) & midperipheral dot & blot hemorrhages are the hallmarks. -FFA shows delayed choroidal & retinal filling. -Carotid Doppler detects carotid stenosis. -PRP helps in NVI. Carotid endarterectomy may be required. Tip-107..... In any posterior segment pathology, NEVER fail to look for Retrolental cells (in anterior vitreous), which indicate inflammation (after excluding vitreous hge & RPE cells of Shaffer‟s sign in RD) & rules out CSC/CSR, AMD & secondaries. Tip-108...... Sheathing of disc & peripapillary vessels is commonly congenital as in Bergmeister‟s papilla (persistent remnants of fetal
vasculature/ hyaloid artery) & is generally of no significance. However, sheathing may also be acquired in various causes of disc edema. Tip-109....... To differentiate Choroidal nevus (flat, gray subretinal lesion) from choroidal melanoma, five Classical features favouring the latter are.... 1. Tumor thickness of >2mm or documented growth 2. Presence of SRF 3. Any visual symptoms 4. Orange pigments over lesion 5. Posterior tumor margin touching the disc Presence of overlying drusen or RPE changes indicate chronicity of lesion & is mostly benign. Tip-110..... Following retinal diseases cause CME but show no leak on FFA... 1. ERM & VMT syndrome 2. X-Linked juvenile retinoschisis 3. Retinitis pigmentosa (RP) 4. Nicotinic acid maculopathy 5. Photic maculopathy
In CMEs with leakage, fluid collection is predominately in OPL (watershed zone between retinal & choroidal circulations), also called Henle‟s layer in fovea & gives rise to classic Petalloid pattern. In CMEs without leakage on FFA, fluid collection is sometimes intracellular & hence may respond to Carbonic anhydrase inhibitors especially in Retinitis pigmentosa (RP). CME of <300mn is generally not easy to make out (no loss of foveal reflex), hence needs imaging for diagnosis. Tip-111..... Retinal Cavernous hemangioma mimics peripheral BRVO. To differentiate- It appears as dense cluster of saccular aneurysms alongside the retinal veins which are neither dilated NOR tortuous unlike BRVO. Aneurysmal dilatations are non-leaky on FFA unlike retinal telangiectasias of Leber‟s miliary aneurysms & Coats‟. Tip-112.... Diffuse or localised reddish/ orangish thickening & discolouration of fundus may be due to rare vascular hamartoma called
Choroidal hemangioma. Commoner vascular tumours of retina & choroid are of 3 types.. 1. Choroidal hemangioma- Majority localised (circumscribed, isolated & asymptomatic- just needing observation; rarely cause serous RD or CME), but sometimes diffuse (part of Sturge Weber syndrome) 2. Retinal capillary hemangioma (Von Hippel syndrome) 3. Retinal cavernous hemangioma- Unlike Capillary hemangioma, it needs no treatment (non-growing) & causes no subretinal fluid or exudation & has no feeder vessels (afferent-efferent). Tip-113..... Identifying BRVO may be difficult in a patient with significant Diabetic retinopathy. FFA clinches the diagnosis. Tip-114..... Blunt trauma with globe compression ruptures the inelastic portions of the eye (viz. RPE, Bruch‟s & inner choroid). Elastic parts (sclera, retina & vitreous) are relatively spared. Secondary CNVM (subretinal/type-2) occurs in 5-10% after choroidal rupture & is highly responsive to AntiVEGF treatment.
Tip-115...... Ultrasonic Biometry falsely records higher axial length in Silicone oil (SO) filled eyes, causing hyperopic refractive error, because speed of sound is reduced by SO (only 1000m/sec as compared to 1550 in normal phakic eye). To compensate, multiply axial length by conversion factor of 0.71. Optical Biometry is preferable in SO filled eyes. Tip-116.... Compulsory use of mask by patients & ophthalmologists has made fogging of specs & all optical Instruments & lenses a major problem. Use Anti-fog spray/solution to avoid. Basically surface tension reducing agents. Work for 3-6 hours. Spray bottle (1 oz/30ml for INR 300/ to 1500/) available with opticians & online (Amazon). Tip-117...... Impending CRVO is seen as dilated, tortuous retinal veins with few hemorrhages & minimal/no loss of vision. Mostly unilateral & is seen in younger patients with
total recovery in most cases, however a few may progress to full attack of CRVO. Tip-118..... In acute CRAO, on FFA, delay in filling of retinal arteries is the most specific sign. Total lack of filling of CRA is seen only in an occasional case. Choroidal flush (filling) should be normal in CRAO, if not, think of Ophthalmic or Carotid artery obstruction. Normally, choroidal filling on FFA occurs within 10-15 seconds of dye injection followed in 2-3 seconds by retinal arterial filling. Tip-119..... Reverse pseudohypopyon is seen with emulsified silicone oil in anterior chamber (oil being lighter than aqueous humor, floats up), while Perfluorocarbon liquid (PFCL) settles inferiorly in AC (being heavier than aqueous humour) & is seen as round, clear oil bubbles. Tip-120..... For good Fundus imaging with fundus camera... -Use internal fixation target for central (macular) imaging & external target for peripheral imaging, if both required.
-Take peripheral image first (if required) & then central to increase patient‟s cooperation. -With large pupils, reduce flash intensity to avoid over exposed photo. -With non-mydriatic camera, covering the other eye dilates the pupil little more. Give sufficient time for pupil size to recover after the flash. -In smaller non-dilating pupils, try off-axis photography, this moves dark shadow away from macula & disc. -Keep objective lens clean (with cleaning tissue start from centre & move out spirally). Tip-121..... The retinal layer(s) primarily affected in certain diseases is/are (helpful in OCT interpretation)..... -RNFL & GCL- In Sphingolipidosis (Lipid storage disorders) -Inner retina (RNFL to OPL)- DR, Vascular occlusions -OPL- CMEs (with or without leakage on FFA), Lipid deposits in DR, Coats‟, RAM, Angiomatosis -ONL & Photoreceptor layer- Cone dystrophy, Achromatism (achromatopsia) & Phototoxicity -RPE- Best, Stargardt, Drusen, CQ & Phenothiazine toxicity
-Bruch‟s- Angioid streaks, Choroidal rupture & Lacquer cracks (high myopia) -RPE-Bruchs-Choriocapillaris complexAMD, CSR, VKH, Melanoma, Metastasis Tip-122..... Features of Ischemic CRVO unlike nonischemic are.... 1. Visual acuity of <6/60 2. RAPD 3. Extensive retinal hemorrhages 4. Severe engorgement & torturousity of all branches of CRV. 5. Multiple soft exudates (6 or more). 6. Abnormal ERG- decreased b-wave amplitude 7. Extensive CNP areas (>10 disc diameter) on FFA (done after 3-6 months) For management, see Tip-25. Tip-123...... FUNDUS AUTOFLUORESCENCE (FAF).... -Detects fluorescence from Lipofuscin (LF) in RPE non-invasively. Lipofuscin formed as by-product (of vitamin-A) from phagocytosed outer photoreceptors‟ segments. LF is the least in fovea, but more in posterior pole and decreases towards periphery. -LF increases with age & in RPE metabolic
dysfunctioning. -Normal retina is mildly autofluorescent with dark vessels (blood absorbs AF of LF), disc (no LF) & macula (luteal pigment also absorbs autofluorescence/AF) -Good pics of FAF became possible because of CSLO (detects such low levels of AF) -HypoAF occurs in RPE atrophy/loss, intraretinal fluid/hge, scar or excess lutein. -HyperAF occurs in Drusen, older hges, Increased LF in RPEs. -Optic disc appears dark on FAF photos unlike in Red-free (white disc) -FAF can‟t be done if Fluorescein dye is already injected (same wavelength filters used in both) -Most useful to follow up Geographic atrophy (dry AMD) as increasing hyperAF in junctional adjoining zones indicates more progression likely. Tip-124..... Extensive Asteroid hyalosis may interfere in clear fundus viewing, but it doesn‟t obstruct in good fundal imaging on FFA. Tip-125..... Diabetic retinopathy may look very mild on cursory fundus examination in busy OPD. However, FFA might reveal serious changes in fundus. Hence, always order an FFA, if in
doubt. Tip-126..... Old CRAO on fundus exam is recognised by... -Diffusely narrowed retinal arterioles persist. -No retinal edema (opacification/ whitening) is seen after 4-6 weeks. Diffuse inner retinal atrophy & thinning ensues. RAPD persists. -Pale disc (atrophy). FFA is usually normal in old CRAO, as the circulation is restored. Tip-127..... Intravitreal tap by syringe for specimen collection in Endophthalmitis is not advocated by many vitreo-retinal surgeons. However, it may be tried by comprehensive ophthalmologist (if he is conversant with giving Intravitreal injections, which he should be, as he may require it to give it to his own postop endoph case, especially if referred vitreous surgeon is far off). For tap, always „break‟ the vacuum in syringe before entering. Abondon, if dry (no liquefied pocket there). Vitreous biopsy is then safer by vitrectomy probe after making 3 ports, followed immediately by Vitrectomy.
Tip-128..... RETINOBLASTOMA.... -80% have calcification (detected easily on USG-B scan- high internal reflectivity spikes & on CT scan) . -Most important mortality indicator is optic nerve extension (cut long stump, if enucleating). -One-third are B/L & multifocal, which present earlier (mean age-1 year against 2years of U/L) & are mostly heritable (germinal mutation of RB1 tumor suppressor gene). Get genetic testing in excised tumor or in blood. -Chemoreduction & Intra-arterial chemotherapy (by Ophthalmic artery cannulation) are most promising therapies. Tip-129...... Laser (NOT the PRP which is done in PDR) is the Gold standard treatment of ROP. I-Vit Anti-VEGF (half of the adult dose) is given if Laser is not available or possible (as in non-dilating pupil or hazy media). Disadvantages of I-Vit Anti-VEGF- delays normal retinal vascularisation, increases retinal traction, more likely late recurrences & systemic side effects.
Advantages- myopia less likely, less time consuming, no intubation required, laser more damaging in zone-1 (posterior pole), better results in APROP cases, also useful as adjunct before vitrectomy for stage-4 & 5, Laser doesn‟t treat VEGF already present in vitreous. As per latest recommendations, use smaller needle (4mm long, 31-32G) at 1 mm posterior to limbus for I-Vit injection in newborn. Remember, newborns have disproportionately large lens & no Pars plana. Tip-130..... Retinal complications in Covid-19 (SARS CoV-2) infection.... Occlusion of terminal retinal arterioles of RNFL & GCL causes ischemia & infarction seen as superficial (flame shaped) hemorrhages & cotton wool spots. HIV, Dengue & Zika viruses cause similar complications. Damage is caused directly by virus or immunogenic or thrombotic coagulopathy. Tip-131...... Important D/D of ROP in newborn is rare B/L vitreo-retinopathy- Familial exudative vitreo-retinopathy (FEVR). FEVR is inherited, retinal angiogenic disorder with
avascularisation causing ischemia & neovascularisation of peripheral retina with subsequent exudation & vitreo-retinal tractions. Unlike ROP, FEVR occurs in TERM babies without h/o oxygen therapy & is progressive for years. Coat‟s disease & PFV (earlier called PHPV) are also similar vitreo-retinopathies of newborns, but are generally U/L. Tip-132..... In acute CRAO (sudden visual loss), classical retinal whitening, cherry red fovea & box-carring may take few hours to develop, till when the fundus may appear totally normal. Irreversible retinal injury starts after 90 minutes of total CRAO, however try measures (decreasing IOP & digital massage to dislodge embolus) for upto 24 hours. Visual loss in CRAO most closely correlates with ensuing degree of retinal opacification/edema. Tip-133..... Subthreshold Laser (STL) is/has.... -Low powered & is invisible (infrared) during application time. -Theoretically minimises collateral thermal damage beyond RPE (ie to NSR), especially
useful in macula unlike conventional lasers. ? Less likely ERM, field defects & CNVM (side effects of conventional lasers). -Micropulse laser (eg Iridex) is STL with pulses in microseconds (milliseconds in conventional lasers) -Presently, NOT considered the first-line treatment. -Being invisible on application, over & under treatment likely with difficult reapplications. -Transpupillary Thermal Therapy (TTT) was also a type of STL. Tip-134..... Roth spots (white centered superficial retinal/RNFL hemorrhages)- first described & considered pathognomonic in SABE may occur in host of systemic diseases affecting retinal capillaries (eg DM, HT, Anemias, Leukemia, HIV, etc.). Whitish centre is platelet-fibrin thrombus plugging the ruptured capillary. Tip-135...... Photodynamic Therapy (PDT)... -uses Verteporfin (Visudyne)- a photosensitizer. -uses low power (full fluence is only 600 mW/sq.cm), long duration (83 seconds), infrared laser (689nm).
-FDA approved for wet AMD in 1999, but now only used as second line treatment. Combined therapy (full fluence PDT with Ranibizumab) now preferred. -Now also used in chronic CSR & retinal capillary hemangioma. -Main side effect is photosensitivity- patient has to cover skin fully, face & eyes for 3 days after treatment. Wear gloves, sunglasses and wide-brimmed hat. Tip-136.... OCULOMICS... is identifying ocular biomarkers of systemic diseases. Retina by fundus imaging & OCT is also being used non-invasively for this purpose. e.g. In Alzheimer's- RNFL thinning & increased hard druse in retinal periphery. In calculating risk of MI & Stroke- more changes of HT retinopathy, Decreased AV ratio (either arteriolar constriction or venous dilatation) pose higher risk. Tip-137..... During FFA... -Take colour & Red-free photos first. -Predecide- which eye to start with first. -Inject dye rapidly (after test dose for anaphylaxis) within 5 seconds.
-Start with photos of Disc & macula in preferred eye initially. Go clockwise all around the periphery clicking photos. - Follow same for other eye. -If both FFA & ICGA are planned, ICGA is first performed followed by FFA, while waiting for late films of ICGA. Tip-138...... ILM peeling is considered an integral part of Full thickness macular hole (FTMH) surgery unlike in ERM surgery, where its role still remains controversial. FTMH is now considered as macular dehiscence, starting as foveal detachment because of tangential traction & NOT the dissolution of tissue. Tip- 139..... Leber congenital amaurosis (LCA) is the only congenital eye (retinal) disease where Gene therapy has been approved by USFDA (2018) in one of its variants (in approx.. 10% cases with RPE65 gene mutation). LCA is the most common inherited (autorecessive) blindness of children, presenting with marked visual impairment, nystagmus & abnormal ERG in newborn. Fundus picture is variable, being normal initially or later showing bone-spicule
pigmentation or flecks or whitish plaque lesions. Tip-140.... Combined CRAO & CRVO is rare but possible disease. Patient presents with sudden, unilateral, severe painless loss of vision. Patient has RAPD with features of both CRVO (retinal hemorrhages with 'tortuous' & dilated retinal veins) & CRAO (retinal opacification/ edema with cherry red fovea). CRAO fundus findings resolve faster than CRVO. Prognosis remains poor. Tip-141..... The importance of differentiating Classic (Type-2/Subretinal) or Occult (Type-1/subRPE) CNVM in ARMD is now reduced, as both need Anti-VEGF as first line therapy. Tip-142..... Pathognomonic feature of Stargardt's disease (Fundus flavimaculatus) on FFA is total loss of background choroidal fluorescence in early phases, so called 'Silent choroid' (blocked by lipofuscin like material. It doesn't correlate with severity or duration of disease.
Tip-143..... In retinal laser, 3 parameters are adjustable viz. 1. Power in milliwatts (mW), 2. Duration of exposure in seconds (0.1 second usually) & 3. Spot size (100-300 mn usually). While in YAG laser, only one parameter is variable- Energy in milliJoules(mJ). Energy =Power x Time. Energy is what one delivers & Power is the rate at which it is delivered. Tip-144..... Pregnancy predisposes to progression of Diabetic retinopathy (DR). Elevated HbA1C levels at baseline are associated with higher risk of DR, hence close monitoring is essential & preferably keep it below <6%, without causing significant hypoglycemia. Gestational diabetics don't develop DR. Pregnancy has no long term effects on DR. Tip-145..... Cluster Endophthalmitis (CE) in India is most commonly caused by Pseudomonas aeruginosa (usually Multi-drug resistant) & is because of exogenous contamination as Pseudomonas is not the normal conjunctival flora.
New organisms (eg Stenotrophomonas/aerobic gram negative bacteria, etc.) responsible for CE are now being reported worldwide. Tip-146.... Artificial intelligence (AI) using computer algorithms in ophthalmology is now most commonly used for 3 retinal diseases viz. DR, AMD & ROP. It can greatly help in real-time tele-ophthalmology screenings. Tip-147..... Retinal Function Imager (RFI by Optical Imaging Ltd., Israel) is a new non-invasive, stroboscopic, fundus imaging camera, which detects functional changes in retinal vasculature before structural changes can be detected clinically or on conventional imaging. It provides retinal blood flow velocity, non-invasive capillary perfusion maps (nCPM), blood oximetry & metabolic demand of retina. It has higher field of view & resolution than OCTA. Tip-148..... In patients of pathological myopia with severe chorioretinal atrophy, chances of missing a retinal break are high on I/O & also during surgery.
Tip-149..... In RVO related macular edema, both AntiVEGF & Dexamethasone implant (Ozurdex) have similar efficacy, however the former have lesser adverse effects. Thus, Ozurdex is usually the second choice in these cases, being more often indicated in pseudophakes & anti-VEGF's non-responding cases. Tip-150...... Pachydrusen- are large (>125mn) drusen seen as hallmark of Pachychoroid disease (see Tip-29), but are different from soft drusen of AMD, being scattered even around the optic disc & have "well-defined" & complex margins. They may be isolated or in clusters. These are sub-RPE deposits seen as yellowish deposits on fundus photos. Tip-151..... Purtscher retinopathy is U/L or B/L retinal disease with extensive hemorrhages, edema & soft exudates in posterior pole following severe crushing injuries of head or body causing intravascular coagulopathy & microembolisation. While Purtscher like retinopathy has similar fundus picture following many systemic diseases causing systemic microembolisations e.g. in amniotic
embolism, pancreatitis, connective tissue diseases, etc. Empirically steroids are used. Tip-152..... Macular pseudohole is a clinical diagnosis where... -Contracting ERM in macula heaps up the tissue around the macular centre. -Watze-Allen sign on fundus biomicroscopy is negative (no break in slit-lamp beam noticed by patient) -Metamorphopsia is common but no central scotoma is noticed by patient. -OCT scan confirms no loss of central macular tissue unlike full thickness macular hole. Tip-153.... Clinical appearance of Macular CNVM.... -Greyish-green deep (sub-retinal/RPE), elevated lesion with hyperpigmented borders. -lesion has SRF, edema, exudation or hemorrhages. Tip-154..... Retinal Angiomatous Proliferation (RAP) is a distinct form of AMD with type-3 CNVM. 'Intraretinal' neovascularisation starts from deep capillary plexus in macula & then
infiltrates deeply towards RPE & choroid (retino-choroidal anastomosis). Patient usually presents in its late stage-3 with fluid on OCT seen under RPE, NSR & Intraretinal, although maximum fluid is Intraretinal. Tip-155..... Both Retinal Angiomatous Proliferation (RAP) & Parafoveal Telangiectasia (PFT/MacTel) show telangiectatic macular vessels, but PFT never causes PED, as it doesn't affect RPE & only very rarely causes CNVM. Tip-156..... Severe NPDR has any one of the following (Rule of 4-2-1), but no neovascularisation... -Intraretinal hges or micros in all 4 quadrants. -Venous beading in any 2 or more quadrants. -IRMAs (see Tip-20) in 1 or more quadrants. Any patient with 2 or more of above 3 characteristics is having “Very severe NPDR”. Tip-157.... Photocoagulation for Diabetic maculopathy is now only used for focal macular edema
outside FAZ. Macular grid for Diffuse diabetic macular edema (DDME) is now given up in favour of repeated Anti-VEGF injections. Tip-158..... Hypertensive Retinopathy (HTR) of whichever grade (even of grade-iv in acute hypertensive crisis with disc & macular edema) needs no special ophthalmic treatment but requires urgent medical control of BP & close monitoring. No antiVEGF required for macular edema. Most patients regain good vision, however chronic disc or macular edema can cause vision loss. Tip-159..... Paracentral acute middle maculopathy (PAMM) & Acute macular neuroretinopathy (AMN) can be differentiated on SD-OCT scan. In PAMM, hyper-reflective plaque lesion is seen inner to outer plexiform layer, while in AMN, lesion is outer to OPL (i.e. in photoreceptors). Patients in both the diseases present with unilateral, sudden onset paracentral scotoma but commonly have near normal vision & fundus. Both are actually microvascular Intraretinal infarcts.
Tip-160.... In OCT macular scan interpretation, 2 basic points to be noted are1. Identify different layers & note which layer(s) is/are predominantly affectedvitreoretinal interface or inner or outer (ELM to RPE) retina? 2. Whether lesion is hypo or hyperreflective? Tip-161..... Different types of Pigment epithelial detachments (PEDs) can be differentiated on OCT scan e.g.. 1. Serous PED- is filled with hyporeflective, homogeneous fluid. 2. Hemorrhagic- is filled with hyporeflective, homogeneous fluid (sometimes partly heterogeneous) but casts a shadow obscuring underlying choriocapillaris. 3. Fibrovascular- has heterogeneous & hyper-reflective contents. 4. Drusenoid- has homogeneous & hyperreflective contents. Tip-162..... Synchisis scintillans, (cholesterol crystals because of vitreous degeneration) unlike Asteroid hyalosis may be seen in both anterior chamber and vitreous & are free floating (not attached to vitreous
framework) & settling down with gravity. Also Asteroid hyalosis are fixed & noniridescent unlike Synchisis. Tip-163.... Exudative retinal detachment (RD) unlike Rhegmatogenous RD has dome-shaped elevation with gravity dependent shift of subretinal fluid. Retina remains more transparent & has more turbid fluid unlike Rhegmatogenous RD. Rhegmatogenous RD always extends towards ora serrata unlike exudative. Always try to find the cause in exudative RD which could be Inflammatory, vascular or tumour. Tip-164..... Diabetic papillopathy is U/L or B/L mild optic disc edema with mild visual loss & self recovering in 2-3 months. It is a variant of non-AION & has no association with diabetic retinopathy. It is mainly a diagnosis of exclusion (rule out AION, NVD, optic neuritis, etc). Tip-165.... Prophylactic laser for fundal coloboma to prevent Rhegmatogenous RD is a controversial subject, although some studies have shown it to be beneficial. 3 contiguous
rows of laser spots are applied all around at the coloboma edges except in macular area (i.e. sparing area between 2 temporal retinal vascular arcades). Tip-166...... 2 developmental anomalies of peripheral retina that have strong vitreo-retinal adhesions are... 1. Vitreo-retinal tufts- small whitish retinal elevations looking like snowball opacities on retinal surface. 2. Meridional folds- perpendicular retinal fold (pleat) between two oral bays. Both very rarely cause RD & are usually the incidental findings requiring NO prophylactic treatment. Tip-167..... Most common manifestation of TB in eyes is granulomatous uveitis (mostly posterior uveitis in form of choroidal tubercles).These patients should get systemic steroids along with ATT to prevent the damage. Most patients with active ocular TB have no h/o systemic or pulmonary TB. Chest CT is better than plain X-ray. In Mx test, >10 mm induration is considered positive in endemic areas. Interferon-gamma release assay tests (e.g. Quantiferon TB gold
test -QFT-G) gives less false positive tests than Mx in prior BCG vaccination. Tip-168..... Choroidal melanocytoma is a benign greyish-black or dark brown tumour with feathery margins occuring on or near the optic disc. Probably a variant of Choroidal nevus that has overlied the disc. Treatment is observation. OCTA is an important tool to know its depth & progression (occurs in 15%). Tip-169..... ERG detects electrical activity generated by stimulating retina & recording it at corneal level (by corneal electrodes). Patient needs to have well dilated pupils, steady fixation & could be light (for cone response) or dark adapted (for Rod response). Full-field ERG (ffERG) is a mass response useful in widespread retinal dysfunction. Focal ERG (fERG) is for central macula. While Multifocal ERG (mfERG) is for central 30° (61 or 103 points) & done under light adapted conditions only (i.e. for cones only) & is done for localised macular abnormalities e.g. HCQ toxicity. Its waveforms are N1, P1 & N2 (initial
negative, then positive & second negative deflection) unlike negative 'a' (from both rods & cones) & positive 'b' wave (from bipolar cells) of ffERG. Tip-170.... Eales' disease in general is considered as diagnosis of exclusion (being idiopathic/ hypersensitivity to tuberculo-protein) & other causes of Vasculitis must be ruled out (see Tip-55). It passes through 3 overlapping stagesRetinal periphlebitis, ischemia & neovascularisation. Wide field FFA has allowed earlier missed findings of Eales also to be discovered in time. Tip-171.... LogMAR/ETDRS chart is more accurate than Snellen. Recorded at 4m for distance. Each row has 5 letters (optotypes) & each letter has score of 0.02 log units. Formula of logMAR acuity= x-0.02y, where x is logMAR value of line completely read (mentioned on chart) & y is the number of letters missed in a lower row. To convert Snellen acuity to logMAR value say of 6/60- Inverse the Snellen value 60/6 =10 & then take log of 10 i.e. 1.00.
Tip-172.... Xanthophyll is present in IPL & OPL (more) of macula & has peak absorption of 460nm i.e. closer to blue light; hence green, yellow or red wavelengths (higher) are preferred in retinal lasers to avoid macular damage. Diode laser had still higher wavelength (Infrared- 810nm), hence better for macula, however it penetrates deeper causing choroidal pain. Tip-173.... Acute cilioretinal artery occlusion...... -Cilioretinal artery normally fills during choroidal (pre-arterial) phase of FFA. -Seen as retinal edema (whitening) in papillomacular area. -99% are unilateral & if isolated, visual loss is usually only mild. -May be caused by inflammatory retinitis e.g. Toxoplasmosis in which retrolental inflammatory cells are always present. -If associated with AION, always think of GCA (systemic steroids compulsory). Tip-174.... Hypertensive choroidopathy (seen in severe HT) is less common than Hypertensive Retinopathy & can manifest as...
1. Elschnig spots- RPE damage due to underlying choriocapillaris infarction. Seen as well demarcated, round, white or yellow spots in acute phase of hypertension in perimacular or peripapillary region. Later they become pigmented. 2. Siegrist streaks- are hyperpigmented, linear streaks along the choroidal arteries in periphvery. 3. Serous RD All these changes indicate choroidal infarcts due to choriocapillaris damage. Tip-175..... Most uveitis cases have KPs in inferior cornea, while diffusely scattered KPs are characteristically seen in Fuch's heterochromia iridocyclitis (Fuch's uveitic syndrome/FUS) & Herpetic iridocyclitis. FUS is U/L, chronic, anterior, often asymptomatic, uveitis with occasional vitreous involvement. It NEVER shows ciliary congestion or posterior synechiae. Steroids have NO role. Treatment is symptomatic if cataract or glaucoma develops. Tip-176..... Chronic asymptomatic Rhegmatogenous retinal detachment is generally inferior with hyperpigmentation or loss of pigment in