Use of Ranibizumab for the Treatment of Edema of the Macula
To assess the benefit of increased follow-up and treatment with ranibizumab between months 24 and 36 in the Ranibizumab for Edema of the Macula in Diabetes (READ-2) Study, investigators conducted this prospective, interventional, multicenter follow-up.
Patients who agreed to participate between months 24 and 36 (ranibizumab, 28 patients; laser, 22; and ranibizumab + laser, 24) returned monthly and received ranibizumab, 0.5 mg, if foveal thickness (FTH, center subfield thickness) was 250 µm or greater. Improvement in best-corrected visual acuity (BCVA) and reduction in FTH between months 24 and 36 were the main outcome measures.
According to the investigators, mean improvement from the baseline BCVA in the ranibizumab group was 10.3 letters at month 36 vs. 7.2 letters at month 24 (ΔBCVA letters = 3.1, p=.009), and FTH at month 36 was 282 µm vs. 352 µm at month 24 (ΔFTH = 70 µm, p=.006). They reported that changes in BCVA and FTH in the laser group (–1.6 letters and –36 µm, respectively) and the ranibizumab + laser group (+2.0 letters and –24 µm) were not statistically significant. They also noted that the mean number of ranibizumab injections was significantly greater in the ranibizumab group compared with the laser group (5.4 vs. 2.3 injections, p=.008), but not compared with the ranibizumab + laser group (3.3, p=.11).
More aggressive treatment with ranibizumab during year three resulted in a reduction in mean FTH and improvement in BCVA in the ranibizumab group, the investigators concluded. More extensive focal/grid laser therapy in the other two groups may have reduced the need for more frequent ranibizumab injections to control edema. Long-term visual outcomes for treatment of diabetic macular edema with ranibizumab are excellent, but many patients require frequent injections to optimally control edema and maximize vision.