Ocular Findings at Initial Pan Retinal Photocoagulation for Proliferative Diabetic Retinopathy Predict the Need for Future Pars Plana Vitrectomy

In Brief Purpose: To determine the 1-year and 2-year likelihood of vitrectomy in diabetic patients undergoing initial pan retinal photocoagulation (PRP). Methods: Diabetic eyes receiving initial PRP for proliferative diabetic retinopathy (PDR) were analyzed to determine their risk for vitrectomy based on clinical findings. Results: In total, 374 eyes of 272 patients were analyzed. The percentage of eyes undergoing vitrectomy 1 year and 2 years following initial PRP was 19.1% and 26.2%, respectively. Of the eyes in Group 1 (PDR alone), Group 2 (PDR and vitreous hemorrhage), and Group 3 (PDR and iris neovascularization, vitreous hemorrhage with traction or fibrosis, or fibrosis alone), the percentage receiving pars plana vitrectomy at 1 year and 2 years was 9.73% (18/185) and 15.7% (29/185), 26.9% (43/160) and 34.4% (55/160), and 37.9% (11/29) and 48.3% (14/29), respectively. Eyes in Group 2 had 2.78 times greater likelihood (P < 0.0001) and eyes in Group 3 had 3.54 times higher likelihood (P < 0.0001) of requiring pars plana vitrectomy within 2 years than those with PDR alone. Conclusion: Eyes receiving PRP for PDR with associated hemorrhage or traction were more likely to undergo pars plana vitrectomy within 1 year and 2 years following initial PRP compared with eyes with only PDR, providing important prognostic information for PRP-naive patients. Following initial PRP, 19.1% and 26.2% of patients with proliferative diabetic retinopathy underwent vitrectomy at 1 year and 2 years, respectively. Clinical findings such as vitreous hemorrhage and fibrovascular traction led to an increased likelihood of vitrectomy.