Abstract
Purpose: :
To compare ranibizumab dose response in the treatment of clinically significant diabetic macular edema.
Methods: :
Investigator sponsored, prospective, randomized clinical trial. Eyes with clinically significant macular secondary to diabetic retinopathy were randomized to one of two groups, 0.5mg or 1.0mg ranibizumab at baseline. During the first year, three monthly injections were given followed by as-needed injections on alternate months. Starting at Month 12, patients were followed monthly and could receive as-needed treatments at these visits. An amendment allowed treatment with 2.0mg ranibizumab in patients who had completed at least 12 months of follow-up.
Results: :
: A 24-month interim analysis was performed. Both groups had similar baseline characteristics. At Month 24, significant visual acuity gains from baseline were observed in both 0.5mg and 1.0 mg groups. There was a significant mean decrease in central foveal thickness in both the 0.5mg and 1.0mg groups. In the 0.5mg group, a smaller proportion of patients gained 15 or more ETDRS letters compared to patients in the 1.0mg group. The average number of injections in the 0.5mg group was similar as compared to the 1.0mg group. Fifteen patients received 2.0mg ranibizumab starting at or after Month 24. In this subset, visual and anatomic outcomes were maintained through follow-up. When compared to the 6 months preceding the transition to the 2.0mg dose, the average time (days) between treatments increased in both groups (0.5mg vs 2.0mg: 49 vs 66; and, 1.0mg vs 2.0mg: 45 vs 56).
Conclusions: :
Treatment of CSDME with 1.0 mg of ranibizumab resulted in a statistically significant improvement in visual acuity from baseline. There was a trend towards greater improvement in ETDRS visual acuity and improved resolution of macular edema with 1.0 mg ranibizumab versus 0.5 mg ranibizumab at 24 months. The number of injections did not differ significantly between the two groups.
Clinical Trial: :
http://www.clinicaltrials.gov NCT00440609
Keywords: diabetic retinopathy • edema • diabetes