Comparison of Anti-VEGF, Steroid, and Combination Therapy in the Treatment of Retinal Vein Occlusion

Abstract

Macular grid laser photocoagulation was the standard therapy for RVO (retinal vein occlusion) for many years, but several newer studies have come along in the last 6 years that introduced new injectable agents like anti-vascular endothelial growth factor (anti-VEGF) and corticosteroids. The BRAVO, CRUISE, Galileo and Copernicus studies looked at anti-VEGF as treatment, and the Ozurdex/Geneva study and SCORE involved corticosteroids.The Ozurdex/Geneva study compared intravitreally injected dexamethasone implant with a sham in both CRVO and BRVO patients. Patients received either 2 injections of 700-μg dexamethasone intravitreal implant (Ozurdex, Allergan) 6 months apart or 1 sham injection and then 1 implant injection 6 months later. The data showed that sustained-release dexamethasone (Ozurdex, Allergan) was effective in treating macular edema in BRVO and CRVO, and patients had a mean improvement in BCVA (best corrected visual acuity) of about 10 letters. When patients were reinjected, they achieved the same improvement in visual acuity in the second 6 months. The SCORE study investigated a special preparation of triamcinolone (Trivaris, Allergan). Patients were injected with the agent every 4 months. The results showed that for CRVO, triamcinolone was superior to observation, and for BRVO, laser was better than triamcinolone. The BRAVO and CRUISE studies observed how well intravitreal injections of ranibizumab worked to treat BRVO and CRVO, respectively. The BRAVO data showed a gain of 18.3 letters in BCVA with a 0.5-mg injection, 16.6 letters with a 0.3-mg injection, and 7.3 letters in the sham group. The CRUISE study showed similar 6-month results, with patients gaining 14.9 letters in the 0.5-mg group, 12.7 letters in the 0.3-mg group, and 0.8 letters in the sham group. The Galileo and Copernicus studies evaluated monthly aflibercept for the treatment of macular edema in patients with CRVO. In both studies, patients received monthly injections for 6 months with the agent or with a sham injection. In Copernicus, all patients were switched to as needed dosing at 6 months, while in Galileo only patients initially treated with the agent were retreated on an as-needed basis. At 1 year, the mean change in vision was + 16.2 letters in the aflibercept group in Copernicus and + 16.9 letters in the Galileo group, versus + 3.8 letters in both sham groups. A recent emerging idea is to treat RVO with both intravitreal sustained-release dexamethasone and anti-VEGF agents (combination therapy) which has been shown to improve visual acuity and prolong the time between injections (reinjection interval). In our study, patients with both CRVO and BROV received anti-VEGF injections (either bevacizumab, ranibizumab, or aflibercept) followed by 0.7-mg dexamethasone intravitreal implant (Ozurdex) 2 weeks later. Patients were evaluated every 2-4 weeks until the next anti-VEGF injection. The mean BCVA increased from 9.4 to 16.8 letters during the course of the initial study (by 6 months), and the mean peak improvement in BCVA across all re-treatment cycles was 12.5 letters for BRVO and 20.1 letters for CRVO (a longer term evaluation). This study showed that the addition of dexamethasone intravitreal implant 2 weeks following anti-VEGF therapy provides improvements in BCVA and macular thickness in patients with RVO and increases the percentage of patients whose macula was essentially fluid-free compared with anti-VEGF therapy alone.