Retinal Venous Occlusive Disease

Retinal venous occlusion (RVO) includes central retinal vein occlusion (CRVO), hemi-central retinal vein occlusion (HCRVO), and branch retinal vein occlusion (BRVO). The most important risk factor for RVO is hypertension, but other risk systemic factors include advanced age and cardiovascular disease. Ocular risk factors include glaucoma, cataracts, and age-related macular degeneration. As such, these patients should be assessed for hypertension with metabolic and lipid panels. A hematologic workup for hypercoagulability could be considered for patients under age 50. CRVO is occlusion of the entire retinal venous system at or posterior to the optic nerve head. Patients typically present with acute, painless, monocular vision loss. More severe cases of CRVO with risk of developing neovascularization have 20/200 vision or worse in 99% of cases. Visual field defects can be variable, but a central scotoma is common in CRVO with risk of neovascularization. Neovascularization of the iris or angle may be present, and a relative afferent pupillary defect may also be present, especially in cases with risk of neovascularization. Fundus examination may show patchy retinal whitening from ischemia, macular edema, cotton wool spots, lipid deposits, venous engorgement and tortuosity, arterial attenuation, optic disc edema and pallor. HCRVO occurs when the occlusion is at the major bifurcation of the retinal vein. BRVO is an occlusion of a tributary of the retinal vein at the arteriovenous crossing site. Patients with BRVO have variable vision loss depending of macular involvement. Major BRVO can cause a visual field defect in the corresponding quadrant. Fundus findings with BRVO include intraretinal hemorrhage in a wedge-shaped distribution. There are some diagnostic procedures that are helpful in diagnosing retinal vein occlusions. OCT may show intraretinal fluid, and fluorescein angiography may show intraretinal hemorrhage and neovascularization as well as cystoid macular edema with a petaloid pattern. In managing patients with RVO, it is important to treat the underlying condition (hypertension, glaucoma, etc.). Patient with macular edema are treated with anti-VEGF therapy as a first-line. Intravitreal steroids can be used in resistant cases. Patients with neovascularization of the iris/angle can be treated with pan-retinal photocoagulation.