Prompt Panretinal Photocoagulation Versus Ranibizumab+Deferred Panretinal Photocoagulation for Proliferative Diabetic Retinopathy

The primary objective of the protocol is to determine if visual acuity outcomes at 2 years in eyes with proliferative diabetic retinopathy (PDR) that receive anti-vascular endothelial growth factor (anti-VEGF) therapy with deferred panretinal photocoagulation (PRP) are non-inferior to those in eyes that receive standard prompt PRP therapy. Secondary objectives include: * Comparing other visual function outcomes (including Humphrey visual field testing and study participant self-reports of visual function) in eyes receiving anti-VEGF with deferred PRP with those in eyes receiving prompt PRP. * Determining percent of eyes not requiring PRP when anti-VEGF is given in the absence of prompt PRP. * Comparing safety outcomes between treatment groups. * Comparing associated treatment and follow-up exam costs between treatment groups.