(See Figure 11.9.1.)
Superficial hemorrhages in a sector of the retina along a retinal vein. The hemorrhages usually do not cross the horizontal raphe (midline).
CWSs, retinal edema, a dilated and tortuous retinal vein, narrowing and sheathing of the adjacent artery, retinal neovascularization, VH.
Diabetic retinopathy: Dot-blot hemorrhages and microaneurysms extend across the horizontal raphe. Nearly always bilateral. See 11.12, Diabetic Retinopathy.
Hypertensive retinopathy: Narrowed retinal arterioles. Hemorrhages are not confined to a sector of the retina and usually cross the horizontal raphe. Bilateral in most. See 11.10, Hypertensive Retinopathy.
Disease of the adjacent arterial wall (usually secondary to HTN, arteriosclerosis, or diabetes) compresses the venous wall at a crossing point.
Complete ocular examination, including dilated fundus examination with indirect ophthalmoscopy to look for retinal neovascularization and ME.
OCT: Used to help detect presence and extent of ME as well as monitor response to therapy.
Blood tests: Fasting blood sugar and HbA1c, lipid profile, CBC with differential, PT/PTT. If clinically indicated, consider a more comprehensive workup. See 11.8, Central Retinal Vein Occlusion.
Medical examination: Performed by an internist to check for cardiovascular disease.
An IVFA is obtained after the hemorrhages clear or sooner if neovascularization is suspected.
Retinal neovascularization: Sector PRP to the ischemic area, which corresponds to area of capillary nonperfusion on IVFA. Anti-VEGF medications can also be used particularly if there is concomitant ME.
Prompt and appropriate treatment of underlying medical conditions (e.g., HTN).
Anti-VEGF treatment is now the gold standard. Intravitreal ranibizumab 0.5 mg, faricimab 6 mg, and aflibercept 2 mg are FDA-approved for treating RVO-associated ME. Intravitreal bevacizumab has also been used off-label. Risks of intravitreal injection are low but include VH and endophthalmitis.
Focal retinal laser photocoagulation has historically been the standard treatment if edema is present for 3 to 6 months duration, and visual acuity is below 20/40 with macular capillary perfusion. However, anti-VEGF treatment has supplanted laser. Limitations of focal laser include length of time before effect (often several months) and the need to wait until retinal hemorrhages clear as well as less chance of visual improvement versus anti-VEGF therapy.
Dexamethasone intravitreal implant or off-label intravitreal steroid (e.g., triamcinolone 40 mg/mL, inject 1 to 4 mg). See 11.8, Central Retinal Vein Occlusion.
