Abstract
Purpose:
To report 3-year follow-up of a randomized trial evaluating prompt versus deferred (for ≥24 weeks) focal/grid laser treatment in eyes treated with intravitreal 0.5-mg ranibizumab for diabetic macular edema (DME) causing vision impairment.
Methods:
Data for 361 participants with visual acuity of 20/32 to 20/320 (approximate Snellen equivalent) and DME involving the fovea were reported. The main outcome measures were best-corrected visual acuity and safety at the 156-week (“3-year”) visit.
Results:
The estimated mean change in visual acuity letter score from baseline through the 3-year visit was 2.9 letters greater (95% confidence interval 0.4 to 5.4, P = 0.02) in the deferral group compared with the prompt laser treatment group. In the prompt laser treatment group and deferral group, respectively, the percentage of eyes with a ≥10 letter gain was 42% and 56% (P = 0.02), while the percentage of eyes with a ≥10 letter loss was 10% and 5% (P = 0.12). Up to the 3-year visit, the median numbers of injections were 12 and 15 in the prompt and deferral groups, respectively (P = 0.007), including 1 and 2, respectively, from the 2- up to the 3-year visit. At the 3-year visit, the percentages of eyes with central subfield thickness ≥250 µm on time domain optical coherence tomography were 36% in both groups (P = 0.90). In the deferral group, 54% did not receive laser treatment during the trial. Systemic adverse events appeared similar in the two groups.
Conclusions:
These 3-year results suggest that focal/grid laser treatment at the initiation of intravitreal ranibizumab is no better for vision outcomes, and possibly worse than deferring laser treatment for ≥ 24 weeks in eyes with DME involving the fovea and with vision impairment. Some of the observed difference in visual acuity at three years may be related to fewer cumulative ranibizumab injections during follow-up in the prompt laser treatment group. Follow-up through five years continues. Supported through cooperative agreements from the National Eye Institute and the National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Department of Health and Human Services EY14231, EY14229, EY18817
Keywords: 499 diabetic retinopathy •
585 macula/fovea •
688 retina