Purpose: To evaluate the effectiveness of selective photocoagulation (S-PC) for nonperfusion areas (NPA) in preproliferative diabetic retinopathy (PPDR).
Subjects and methods: A multicenter randomized controlled clinical trial of 69 patients with PPDR showing NPA comparable to or larger than those on reference photographs. The patients were assigned to 2 groups; one was treated with S-PC (PC group: 32 patients), while the other did not receive S-PS (non-PC group: 37 patients). In the non-PC group, panretinal photocoagulation (PRP) was performed whenever proliferative diabetic retinopathy (PDR) developed. In the PC group, S-PC of the NPA was performed followed by additional coagulation whenever the NPA extended, and PRP was performed whenever PDR developed. The primary outcome was the development of PDR.
Results: During the entire course, PDR developed in 18 (26%) of the 69 patients. The incidence was significantly higher in the non-PC group than in the PC group. Comparison of the visual acuity at the time of registration and after 36 months showed no significant differences between the two groups.
Conclusions: S-PC for NPA in PPDR is effective at preventing PDR development.