A 2-year, randomized trial from the Diabetic Retinopathy Clinical Research Network (DRCR.net) has shown ranibizumab (Lucentis) to be the first major treatment advance for proliferative diabetic retinopathy (PDR) in 40 years. Ranibizumab is as effective as panretinal photocoagulation (PRP) in treating proliferative diabetic retinopathy (PDR), and better than laser in preserving patients’ peripheral and night vision.
“These latest results from the DRCR Network provide crucial evidence for a safe and effective alternative to laser therapy against proliferative diabetic retinopathy,” said Paul A. Sieving, MD, PhD, director of NIH’s National Eye Institute, which funded the trial. These findings were presented at AAO 2015 by Jeffrey G. Gross, MD, of the Carolina Retina Center who chaired the study.
Protocol S included 305 patients (394 eyes) in 55 sites across the United States. For participants who enrolled both eyes in the study, one eye was assigned to the laser group and the other was assigned to the ranibizumab group. About half of the eyes assigned to the laser group required more than 1 round of laser treatment. In the other group, ranibizumab (0.5 mg/0.05 ml) was given via injections into the eye once per month for three consecutive months, and then as needed until the disease resolved or stabilized.
The study permitted ranibizumab injections for diabetic macular edema in the laser group, if necessary. Slightly more than half (53 percent) of eyes in the laser group received ranibizumab injections to treat diabetic macular edema. About 6 percent of eyes in the ranibizumab group received laser therapy, mostly to treat retinal detachment or bleeding.
At 2 years, the mean visual acuity letter improvement was not statistically different between the ranibizumab (+2.8) and PRP (+0.2) groups (P < 0.001 for noninferiority). The mean difference in visual acuity over the 2-year period (as measured using the area under the curve) was +4.2 (P<0.001) favoring ranibizumab. Patients receiving laser treatment also had significantly higher loss of peripheral vision (23 vs.-422dB, P<0.001) and higher rates of vitrectomy (15% vs. 4%, P<0.001) and DME (28% vs. 9%, P<0.001).
The authors observed no difference in adverse events, and ocular inflammation rates were similar between groups. One eye in the ranibizumab group developed endophthalmitis. Investigators will continue to follow patients for 5 years.