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RETINAL VEIN OCCLUSION Dr KN POORNESH WGH 03.11.2004.

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Presentation on theme: "RETINAL VEIN OCCLUSION Dr KN POORNESH WGH 03.11.2004."— Presentation transcript:

1 RETINAL VEIN OCCLUSION Dr KN POORNESH WGH

2 CLASSIFICATION BRVO CRVO Major BRVO Non-ischemic Minor Macular BRVO Ischemic Peripheral BRVO Papillophlebitis Hemiretinal Vein occlusion

3 PATHOGENESIS Arteriosclerosis  Compression of the vein  Venous endothelial cell loss Thrombus formation Venous Occlusion

4 PATHOGENESIS Venous occlusion  elevation of venous & capillary pressure     Stagnation of blood flow   Increased tissue pressure Hypoxia of the retina   Damage to capillary endothelial cells & extravasation of blood constituents

5 RISK FACTORS (in order of importance) 1. Advancing age: 50% cases over 65 yrs. 2. Systemic: HT, Hyperlipidemia, Diabetes, Smoking, Obesity. 3. Raised IOP: risk of CRVO 4. Inflammatory: Behcet’s, Sarcoid,AIDS, SLE, Toxoplasma. 5. Hyperviscosity: Polycythemia, MM, Waldenstrom macroglobulinemia.

6 RISK FACTORS 6. Acquired thrombophilic: Hyperhomocystinemia, Antiphospholipid antibody syndrome. 7. Inherited thrombophilic: increased levels of clotting factors 7 & 11, deficiency of antithrombin 3, protein C &S, resistance to activated protein C. Other Risk factors: Hypermetropia (BRVO), Congenital anomaly of Central retinal vein (CRVO), Optic disc drusen, Drugs (OC, Diuretics), Migraine (rare). Retrobulbar external compression: Dysthyroid eye disease, Orbital tumor

7 Major BRVO

8 COURSE of BRVO 6 to 12 months to resolve Venous sheathing Collateral venous channels Microaneurysms, Hard exudates, Cholesterol crystal deposition. Macula: RPE changes or ER gliosis, chronic CME.

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12 Prognosis and Complications of BRVO Depends on Site & Size of occluded vein Integrity of perifoveal capillary network 50% : Recover VA of 6/12 or better. Complications: 1. Chronic macular edema 2. Macular ischemia 3. Neovascularisation, NV (within 3 yrs) 10%- NVD, 20-30%- NVE 4. Recurrent VH, TRD.

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16 Management of BRVO (BVOS) Wait for haemorrhage to clear (3 months). FFA :  Macular edema and VA 6/12 or worse after 3 months –grid laser & follow-up after 2-3 months.  Macular ischemia—no treatment.  5 DD or > area of CNP– 4 monthly follow- up for months.  Neovascularisation– scatter laser

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18 CRVO Ischemic Non-ischemic Frequency 25% 75% VA 20/400 or < (90%)> than 20/400 (90%) Site at lamina cribrosaFar behind lam crib RAPD markedslight VF defect commonrare FundusExt hgs & cotton wool spots, severe disc edema, marked tortuosity of vessels Less exten hgs, few cotton wool spots, mild disc edema, variable tortuosity of vessels

19 CRVO Ischemic Non-ischemic FFAWide spread capillary non- perfusion Delayed venous return, late leakage, good perfusion. ERGReduced “b” wave amplitude, reduced “b/a” ratio normal Prognosis50% develop rubeosis & NVG in 2-4 months 3% develop rubeosis and NVG. 50% return to VA 6/12 or better.

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23 Non-ischemic CRVO ( Course and Follow-up) Residual signs: Disc collaterals, epiretinal gliosis, pigmentary changes at macula. Conversion to ischemic CRVO occurs in 15% of cases within 4 months and 34% within 3 years. Follow-up: should be for 3 years. Prognosis: depends on initial VA, near normal VA in 50%, Chronic CMO- unresponsive to laser (CVOS). 8-10% risk of BRVO or CRVO in the fellow eye.

24 Ischemic CRVO: Management (CVOS) Follow-up: monthly for 6 months  IOP, undilated gonioscopy & SLE Angle NV is the best clinical predictor of NVG. Treatment: PRP in eyes with angle or iris NV. Monthly follow-up until stabilisation or regression.

25 Hemiretinal vein occlusion  Less common than BRVO and CRVO  Occlusion of superior or inferior branch of the CRV.  Features of BRVO, involving the superior or inferior hemisphere  Prognosis depends on severity of macular edema and ischemia.

26 PAPILLOPHLEBITIS (Optic disc vasculitis)  Healthy individuals, < 50 years  Optic disc swelling with secondary venous congestion rather than venous thrombosis.  APD absent, retinal haemorrhages confined to posterior fundus.  Prognosis: 80% -- 6/12 or better 20% visual loss -- macular edema

27 Management:Recent advances  Recent onset of non-ischemic CRVO– high intensity laser to create chorioretinal shunt.  AV sheathotomy for treatment of CME due to BRVO.  Ischemic CRVO:- PP Vitrectomy + Intraocular gas + Radial neurotomy

28 Management: Recent advances  Intravitreal tPA  Transvitreal vein cannulation  Section of posterior scleral ring  Drug therapy -- Troxerutin -- Petroxyfylline -- Hemodilution  Intravitreal Triamcinolone

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