Abstract
Purpose: :
To compare the effects of 3 monthly injections of 0.3 or 0.5 mg of ranibizumab in patients with macular edema due to central retinal vein occlusion (CRVO) or branch retinal vein occlusion (BRVO).
Methods: :
Patients with macular edema due to CRVO (n=20) or BRVO (n=20) were randomized to receive 3 monthly injections of 0.3 or 0.5 mg of ranibizumab. The primary endpoint was at 3 months after baseline and the primary outcome variable was the change from baseline in best corrected visual acuity using an ETDRS protocol. The secondary outcome variable was the change from baseline in excess thickening of the central 1 mm of the retina assessed by OCT.The level of VEGF in aqueous fluid at baseline was measured and correlated with outcome.
Results: :
At the primary endpoint, the median improvement in letters read at 4 meters was 17 in the 0.3 mg group and 14 in the 0.5 mg group for CRVO, and 10 and 18, respectively for the BRVO group. Optical coherence tomography showed that compared to injections of 0.3 mg, injections of 0.5 mg of ranibizumab tended to cause more rapid reductions of central retinal thickening that lasted longer between injections, but by 3 months, excess central retinal thickening was reduced by roughly 90% in all four treatment groups. There was no correlation between amount of improvement and duration of disease or patient age at baseline, but there was some correlation between aqueous VEGF level at baseline and amount of improvement. The mean level of VEGF in the aqueous was significantly greater in patients in CRVO compared to patients with BRVO.
Conclusions: :
These data indicate that excess production of VEGF in the retinas of patients with CRVO or BRVO is a major contributor to macular edema and may influence outcome of treatment with ranibizumab. Both 0.3 and 0.5 mg doses of ranibizumab resulted in substantial improvement in vision and reduction in excess retinal thickening over 3 months. This supports further investigation of both doses of ranibizumab in patients with macular edema due to vein occlusions and suggests that pre-treatment VEGF levels in aqueous may have prognostic significance and deserves further study.
Clinical Trial: :
www.clinicaltrials.gov NCT00407355
Keywords: vascular endothelial growth factor • clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials • ischemia