Purpose: To explore 5-year changes from baseline in diabetic retinopathy severity among eyes treated with ranibizumab for diabetic macular edema.
Methods: Diabetic retinopathy severity was assessed from study visits and annual fundus photographs among participants in Protocol I (DRCR.net). The proportion of eyes that improved at annual examinations and the cumulative probability of worsening through 5 years were estimated.
Results: Among 235 participants with nonproliferative diabetic retinopathy at baseline, there were 29%, 28%, and 32% of eyes with retinopathy improvement at 1, 3, and 5 years, respectively. Among 111 participants with proliferative diabetic retinopathy, corresponding improvement percentages were 38%, 35%, and 23%. The 5-year cumulative probability of worsening was 18% (95% CI: 14%-25%) among nonproliferative diabetic retinopathy eyes and 31% (95% CI: 23%-42%) among proliferative diabetic retinopathy eyes (P = 0.01). In Years 1, 3, and 5, the mean (SD) number of ranibizumab injections was 8.1 (2.5), 2.2 (2.6), and 1.8 (2.6) for nonproliferative diabetic retinopathy eyes, and 9.0 (2.8), 2.3 (2.9), and 1.7 (2.6) for proliferative diabetic retinopathy eyes, respectively. Proportions with improvement or rates of worsening did not change with time.
Conclusion: Individuals receiving ranibizumab therapy for diabetic macular edema may have favorable changes in DR severity throughout a 5-year period concomitant with sequential reduction in anti-vascular endothelial growth factor therapy.