Abstract
For decades, panretinal photocoagulation (PRP) has been the standard of care for the treatment of proliferative diabetic retinopathy (PDR). The relatively recent advent of anti-vascular endothelial growth factor (VEGF) formulations for intravitreal injection has provided a fresh perspective on PDR treatment, especially in eyes with concurrent diabetic macular edema (DME). The anti-VEGF agent ranibizumab has demonstrated a potentially protective effect on eyes with DME in terms of progression to PDR in the RIDE/RISE trials, as has aflibercept in the VIVID/VISTA trials. In 2015, these 2 agents were approved by the Food and Drug Administration for the treatment of PDR with DME, though PRP still remains the standard of care for eyes without baseline DME. Published results from Protocol S illustrate the non-inferiority of ranibizumab versus PRP in the treatment of PDR, the first prospective study to do so in eyes with and without baseline DME. These results also reveal that treatment with ranibizumab, when compared to standard treatment with PRP, may also lead to less peripheral visual field loss, reduced need for vitrectomy, and reduced chance for developing DME. Both PRP and intravitreal ranibizumab have very low rates of adverse events. However, treatment with anti-VEGF agents generally is associated with higher costs, increased need for follow-up, and the risk of potentially catastrophic ocular complications (e.g., endophthalmitis) and systemic side effects. Anti-VEGF agents should be considered in cases of media opacity preventing completion of PRP in compliant patients without recent cerebrovascular accident or myocardial infarction, though the long-term efficacy of these agents remains to be studied, especially after the discontinuation of injections.