Branch Retinal Vein Occlusion (BRVO) is a common retinal vascular disease affecting people over 60 years of age. It is caused by the occlusion of one of the branches of central retinal vein. Some risk factors that may increase the chance of developing BRVO include: hypertension, cardiovascular disease, obesity and glaucoma.
Patients typically complain of a sudden onset of blurred vision or defect in their central field of vision. Upon eye exam, findings may include superficial hemorrhages, retinal edema, and often cotton-wool spots in the area of the retina drained by the affected vein. The obstructed vein will appear to be dilated and tortuous. The superotemporal quadrant is the most commonly affected area for BRVO.
Diagnostic procedures used in BRVO may include fluorescein angiography to assess delayed venous filling, hypofluorescence caused by hemorrhage and capillary nonperfusion, dilation and tortuosity of veins, leakage due to neovascularization and macular edema. Ocular coherence tomography (OCT) is useful to determine the retinal thickness measurements and assess macular edema (swelling).
BRVO treatments aim to manage associated macular edema and neovascularization. Laser treatment of the macular area to reduce macular edema is indicated in patients who have poorer than 20/40 vision and have not experienced spontaneous resolution. Retinal photocoagulation to treat neovascularization is applied to entire involved segment, extending from the arcade out to the periphery. Intravitreal injections of triamcinolone acetonide may be performed treat macular edema. Also, anti-VEGF drugs are being used and investigated further in the treatment of macular edema or neovascularization.