This DRCR.net Protocol S trial sought to determine whether ranibizumab was non-inferior (<5 ETDRS letters) to PRP for visual acuity outcomes in patients with proliferative diabetic retinopathy. Patients were excluded if previous PRP, neovascularisation of the angle, end-stage renal failure, or systemic vascular event within 4 months of randomization. 89 patients had both eyes enrolled; one to each study group. PRP was applied over 1–3 visits, with additional PRP for increased neovascularisation. In the other treatment group, Ranibizumab was given at baseline, and as often as every 4 weeks based on pre-defined criteria and until all neovascularisation had resolved. Both groups could receive ranibizumab for DME (vision <20/32 with central retinal thickening on optical coherence tomography imaging). One eye in the ranibizumab group developed endophthalmitis.

PDR – proliferative diabetic retinopathy; DRCR – Diabetic Retinopathy Clinical Research Network; DM – diabetes mellitus; ETDRS – Early Treatment Diabetic Retinopathy Study; DME – diabetic macular oedema; CI – confidence interval; dB – decibels.

Reference: Writing Committee for the Diabetic Retinopathy Clinical Research Network. “Panretinal Photocoagulation vs Intravitreous Ranibizumab for Proliferative Diabetic Retinopathy: a Randomized Clinical Trial” JAMA, 2015. 2015;314:2137–2146.