Anti-vascular endothelial growth factor for macular edema secondary to central retinal vein occlusion.

BACKGROUND: Central retinal vein occlusion (CRVO) is a common retinal vascular disorder in which macular edema (ME) may develop, with a consequent reduction in visual acuity. The visual prognosis in CRVO-ME is poor in a substantial proportion of patients, especially those with the ischemic subtype, and until recently there has been no treatment of proven benefit. Macular grid laser treatment is ineffective, and whilst a few recent randomized controlled trials (RCTs) suggest short-term gains in visual acuity with intravitreal steroids for patients with non-ischemic CRVO-ME, there is no established treatment for ischemic CRVO-ME. Anti-vascular endothelial growth factor (anti-VEGF) agents have been used to treat ME resulting from a variety of causes and may represent a treatment option for CRVO-ME. OBJECTIVES: To investigate the effectiveness and safety of intravitreal anti-VEGF agents in the treatment of CRVO-ME. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (which contains the Cochrane Eyes and Vision Group Trials Register) (The Cochrane Library 2010, Issue 8), MEDLINE (January 1950 to August 2010), EMBASE (January 1980 to August 2010), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to August 2010), Cumulative Index to Nursing and Allied Health Literature (CINAHL) (January 1937 to August 2010), OpenSIGLE (January 1950 to August 2010), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com) and ClinicalTrials.gov (www.clinicaltrials.gov). There were no language or date restrictions in the search for trials. The electronic databases were last searched on 10 August 2010. SELECTION CRITERIA: We considered RCTs that compared intravitreal anti-VEGF agents of any dose or duration to sham injection or no treatment. We focused on studies that included individuals of any age or gender with unilateral or bilateral disease and a minimum of six months follow up. Secondarily, we considered non-randomized studies with the same criteria, but did not conduct a separate electronic search for these. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trial quality and extracted data. MAIN RESULTS: We found two RCTs that met the inclusion criteria after independent and duplicate review of the search results. These RCTs utilized different anti-VEGF agents which cannot be assumed to be directly comparable. We, therefore, performed no meta-analysis. Evidence from these trials and from other non-randomized case series is summarized in this review. AUTHORS' CONCLUSIONS: Ranibizumab and pegaptanib sodium have shown promise in the short-term treatment of non-ischemic CRVO-ME. However, effectiveness and safety data from larger RCTs with follow up beyond six months are not yet available. There are no RCT data on anti-VEGF agents in ischemic CRVO-ME. The use of anti-VEGF agents to treat this condition therefore remains experimental.