Abstract
Purpose :
It is widely believed that pan-retinal photocoagulation (PRP) laser is a one-episode treatment for proliferative diabetic retinopathy (PDR). This analysis serves to test this belief by evaluating the impact of prior PRP laser and ranibizumab (RBZ) treatment on both the need for additional PRP and on new proliferative events in patients with diabetic retinopathy (DR) with diabetic macular edema (DME) in RIDE/RISE.
Methods :
RIDE and RISE were 2 parallel, randomized, phase 3 trials that evaluated intravitreal RBZ in patients with DR and DME (N=759). Prior PRP was permitted if given at least 3 months prior to screening. Patients were randomized to monthly RBZ 0.3 mg (n=250), RBZ 0.5 mg (n=252), or sham injections (n=257) for 24 months. At month 25, sham-treated patients crossed over to monthly RBZ 0.5 mg. Patients could receive PRP during the study when clinically indicated per protocol guidelines and investigator discretion. Outcomes by baseline PRP treatment status were retrospectively analyzed herein.
Results :
At baseline, 61 (24.4%), 64 (25.4%), and 57 (22.2%) patients in the RBZ 0.3 mg, RBZ 0.5 mg, and sham arms, respectively, had received prior PRP. Among all patients over 24 months, fewer patients in the RBZ arms received PRP than those in the sham arm (2 [0.8%], 3 [1.2%] vs 30 [11.7%] patients in the RBZ 0.3 mg, RBZ 0.5 mg vs sham arms, respectively) (all RBZ vs sham comparisons, P<.0001). Sham-treated patients with prior PRP were almost twice as likely to receive additional PRP during the study compared with patients without prior PRP at baseline (19.3% vs 9.5%, P=.0421). In the RBZ arms, patients with prior PRP did not receive any additional PRP and only a few patients without prior PRP received PRP during the study (1.1% and 1.6% of patients in the RBZ 0.3 mg and RBZ 0.5 mg arms, respectively). Among patients with prior PRP, RBZ treatment reduced the risk of a new proliferative event by approximately 4-fold compared with sham treatment.
Conclusions :
During the first 2 years of the study, among patients with prior PRP, almost 20% of patients in the sham arm received additional PRP in contrast to 0% of patients in the RBZ arms. These data suggest that PRP was not a “one and done” procedure for the treatment of PDR in patients in RIDE/RISE and that RBZ significantly reduced the need for additional PRP.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.