Retina Today - Treatments for Retinal Vein Occlusion: A Review of Recent Developments (April 2014)

摘要

Retinal vein occlusions (RVOs), including both branch and central veins, are the second most common retinal vascular diseases after diabetic retinopathy.1 The Beaver Dam Study reported a prevalence of 0.1% in patients older than 43 years.2 The 15-year cumulative incidence of central retinal vein occlusion (CRVO) was 0.5% in the Beaver Dam Eye Study.3 A cross-sectional study from 6 communities across the United States reported that the prevalence of CRVO was 0.2%. This same study showed that the prevalence of CRVO was similar across different ethnic and racial groups.4 In a population-based study in Australia, the Blue Mountains Eye Study, the 10-year cumulative incidence of CRVO in a population older than 48 years was 0.4%.5 The Singapore Malay Eye Study reported a 0.2% prevalence of CRVO in the Malay population 40 to 80 years old living in Singapore.6 The Beijing Eye Study reported that the prevalence of CRVO in a Chinese population of people 40 years and older was 0.1%.7 No racial or gender predilection for the disease is apparent. There are several systemic factors that have been identified as being associated with RVO, including diabetes, hypertension, and heart disease.2 The standard of care for macular edema secondary to branch retinal vein occlusion (BRVO) has been guided since 1984 by the findings of the Branch Vein Occlusion Study, which showed that macular photocoagulation was superior in improving visual acuity compared with observation.8 The 1995 Central Vein Occlusion Study (CVOS) demonstrated that grid laser treatment of macular edema was of no visual benefit despite the elimination of macular edema in treated eyes.9 Thus, observation for macular edema secondary to CRVO was the standard of care set by this study. Since then, new pharmacologic agents have changed the treatment paradigm of macular edema secondary to RVO. Currently there are 3 treatment options recently approved by the US Food and Drug Administration (FDA) for treatment of macular edema secondary to CRVO. These include a dexamethasone intravitreal implant (Ozurdex, Allergan), ranibizumab (Lucentis, Genentech), and aflibercept (Eylea, Regeneron). Two of these (dexamethasone intravitreal implant and ranibizumab) are also FDA approved for the treatment of macular edema secondary to BRVO. In addition, intravitreal injections of bevacizumab (Avastin, Genentech) have been extensively used off label for treating both CRVO and BRVO. STEROIDS FOR RETINAL VEIN OCCLUSION The SCORE study10,11 compared the effects of 1-mg and 4-mg intravitreal triamcinolone acetonide (IVTA; Trivaris, Allergan) to standard of care, which was observation for CRVO and grid laser for BRVO. In SCORE-CRVO, patients received an average of 2 injections of IVTA over the course of 1 year. At the end of year 1, 27% percent of patients who received 1-mg IVTA and 26% of patients who received 4-mg IVTA achieved a visual acuity gain of 3 or more lines compared with only 7% of patients in the observation group. The visual acuity was sustained throughout year 2. The side-effect profile for the lower dose was more favorable, however, indicating a higher level of safety for the 1-mg dose. In SCORE-BRVO, patients who were randomized to grid laser underwent a mean 1.5 treatments in year 1, and those who received IVTA had an average of 2 injections. At 1 year, the percentage of patients in the laser group, 1-mg IVTA group, and 4-mg IVTA group who gained 3 or more lines of vision was 29%, 26%, and 27%, respectively. These visual acuity gains were sustained to year 3. The rates of cataract formation and intraocular pressure (IOP) elevation, however, were higher in the steroid groups, with a high number of patients requiring cataract surgery between the second and third year of the study. Based on these data, the recommendation from the study was that laser remain the standard of care for BRVO. The GENEVA trial,12 published in 2010, examined the effects of the dexamethasone intravitrea