Anti-vascular endothelial growth factor for macular oedema secondary to branch retinal vein occlusion.

Abstract

Branch retinal vein occlusion (BRVO) occurs when a retinal vein that drains part of the retina becomes blocked. BRVO can affect approximately four to five people per 1,000 of the population. Known risk factors for BRVO include hypertension, atherosclerosis, high cholesterol, diabetes mellitus, and other inflammatory or autoimmune conditions. In a BRVO the severity of vision loss is related to the extent of macular involvement by haemorrhage, swelling (oedema), and poor blood supply (ischaemia). The most common cause of visual loss in patients with BRVO is macular oedema (MO). Patients with BRVO in one eye are at risk of a venous occlusion in the fellow eye. Untreated, approximately one third of affected eyes will achieve a high level of vision (20/40 or better). Current "gold" standard treatment is laser photocoagulation which has been shown to reduce the risk of visual loss and improve the vision in up to two thirds of individuals with macular oedema secondary to BRVO, however, limitations to this treatment exist and newer modalities have suggested equal or improved efficacy. Recent studies have suggested that an injection of anti-vascular endothelial growth factor (anti-VEGF) in the eye may be of benefit to patients with BRVO. In this review, we appraise and present the level of current evidence for the use of anti-VEGF injections in the treatment of macular oedema after BRVO. In total, we found one randomised controlled trial and one quasi-randomised controlled trial. One study from the USA. had 397 participants and compared anti-VEGF injections with sham injections. It demonstrated a potential benefit of repeated anti-VEGF injections to improve vision (at least 15 letters) at one year. A second study with 30 participants, conducted in Italy, compared anti-VEGF injections with laser photocoagulation and did not demonstrate an improvement in vision (of at least 15 letters) of anti-VEGF injections over laser photocoagulation at one year. Antiangiogenic treatment was well tolerated in these studies, but since the studies were only of one year duration, we were unable to discuss long-term effects. There are several ongoing studies which undoubtedly will add to the evidence available.