Painless loss of vision, usually unilateral.

(See Figure 11.8.1.)

Figure 11.8.1: Central retinal vein occlusion with dilated, tortuous vasculature, diffuse retinal hemorrhages in all four quadrants, and macular edema.

Critical

Diffuse retinal hemorrhages in all four quadrants of the retina; dilated, tortuous retinal veins.

Other

CWSs; disc edema and hemorrhages; ME; optociliary collateral vessels on the disc (later finding); NVD, NVI, NVA, and NVE.

• Ocular ischemic syndrome (OIS) or carotid occlusive disease: Dilated and irregular veins without tortuosity. Midperipheral retinal  hemorrhages are typically present, but disc edema and disc hemorrhages are not characteristic. NVD is present in one-third of cases. Patients may have a history of transient visual loss (amaurosis fugax), transient ischemic attacks, or orbital pain. IOP may be decreased. May have pain or intraocular inflammation. Can have abnormal ophthalmodynamometry. See 11.11, Ocular Ischemic Syndrome/Carotid Occlusive Disease.

• Diabetic retinopathy: Hemorrhages and microaneurysms concentrated in the posterior pole. Typically bilateral. IVFA differentiates this condition from central retinal vein occlusion (CRVO). See 11.12, Diabetic Retinopathy.

• Papilledema: Bilateral disc swelling with flame-shaped hemorrhages surrounding the disc. Would not expect as extensive and diffuse retinal hemorrhage and vascular tortuosity. See 10.15, Papilledema.

• Radiation retinopathy: History of irradiation. Disc swelling with radiation papillopathy and retinal neovascularization may be present. Generally, CWSs are a more prominent feature than hemorrhages.

• Atherosclerosis of the adjacent central retinal artery: The artery compresses the central retinal vein in the region of the lamina cribrosa, secondarily inducing thrombosis in the vein lumen.

• HTN: Most common systemic disease associated with CRVO.

• Optic disc edema.

• Glaucoma: Most common ocular disease associated with CRVO.

• Optic disc drusen.

• Hypercoagulable state: Polycythemia, multiple myeloma, cryoglobulinemia, Waldenström macroglobulinemia, antiphospholipid syndrome, factor V Leiden, activated protein C resistance, hyperhomocysteinemia, protein C and S deficiency, antithrombin III mutation, prothrombin mutation, and others.

• Vasculitis: Sarcoidosis, syphilis, systemic lupus erythematosus, and others.

• Drugs: Oral contraceptives, diuretics, and others.

• Abnormal platelet function.

• Orbital disease: Thyroid eye disease, orbital tumors, arteriovenous fistula, and others.

• Migraine: Rare.

Types

• Ischemic CRVO: Vision typically worse (<20/200) with RAPD and visual field defects. Extensive retinal hemorrhage, CWSs, venous tortuosity, and widespread capillary nonperfusion on IVFA (often >10 disc diameters). ERG shows decreased b-wave amplitude. Higher risk of neovascularization.

• Nonischemic CRVO: Vision often better than 20/200, mild or no RAPD, mild fundus changes. Lower risk of neovascularization.

Ocular

1. Complete ocular examination, including IOP measurement, careful slit-lamp examination including gonioscopy when needed to rule out NVI and NVA (both of which are best observed before dilation), and dilated fundus examination.

2. IVFA: Risk of neovascularization proportional to degree of capillary nonperfusion.

3. OCT: Used to help detect presence and extent of ME as well as to monitor response to therapy.

4. If the diagnosis is uncertain, oculopneumoplethysmography or ophthalmodynamometry  may help to distinguish CRVO from carotid disease (but are infrequently performed). Ophthalmic artery pressure is low in carotid disease but is normal to increased in CRVO.

Systemic

1. History: Medical problems, medications (especially antihypertensive medications, oral contraceptives, diuretics), eye diseases?

2. Check blood pressure.

3. Blood tests: Fasting blood sugar and HbA1c, CBC with differential, platelets, PT/PTT, lipid profile.

4. If clinically indicated, particularly in younger patients, consider hemoglobin electrophoresis, RPR or VDRL, FTA-ABS or treponemal-specific assay, ANA, cryoglobulins, antiphospholipid antibodies, factor V Leiden mutation, protein C and S levels, antithrombin III mutation, prothrombin mutation, homocysteine levels, serum protein electrophoresis, and chest radiograph.

5. Complete medical evaluation, with careful attention to cardiovascular disease or hypercoagulability.

1. Discontinue oral contraceptives; change diuretics to other antihypertensive medications if possible.

2. Reduce IOP if increased in either eye. See 9.1, Primary Open-Angle Glaucoma.

3. Treat underlying medical disorders.

4. If NVI or NVA is present, perform PRP. Consider PRP if NVD or retinal neovascularization is present. Prophylactic PRP for nonperfusion is usually not recommended unless follow-up is in doubt. Intravitreal VEGF inhibitors are very effective in temporarily halting or reversing anterior and posterior segment neovascularization. They may be a useful adjunct to PRP, particularly when rapid reversal of neovascularization is needed.

5. No clinical trials have demonstrated efficacy of aspirin 81 to 325 mg p.o. daily.

CRVO-Related Macular Edema

1. Intravitreal ranibizumab 0.5 mg, faricimab 6.0 mg, and aflibercept 2 mg are US Food and Drug Administration (FDA)–approved for treating RVO-related ME. Intravitreal bevacizumab has been used off-label in a similar fashion. Risks of intravitreal injections are low but include VH and endophthalmitis, among others.

2. Dexamethasone intravitreal implant, a biodegradable 0.7-mg implant, is FDA-approved for the treatment of ME associated with RVO. Off-label intravitreal steroid (e.g., triamcinolone 40 mg/mL, injecting 1 to 4 mg) can also be considered and has been effective in both improving vision and reducing vision loss in patients with ME secondary to CRVO. Complications include cataract formation and elevated IOP.

NOTE In a large, prospective, randomized trial (SCORE-CRVO), a 1 mg dose of intravitreal triamcinolone was found to be equally as effective as a 4-mg dose, but with a lower incidence of elevated IOP and cataract formation.

1. Every month initially, with gradual interval taper based on vision, presence of ME, and response to treatment.

2. Evidence of early NVI or NVA should prompt immediate PRP and/or anti-VEGF therapy and monthly follow-up until stabilized or regressed.

3. Patients should be informed that there is an 8% to 10% risk for the development of a branch retinal vein occlusion (BRVO) or CRVO in the fellow eye.