To evaluate the changes of latency and amplitudes of pattern-reversal visual evoked potentials (PRVEP) in patients with proliferative diabetic retinopathy after panretinal photocoagulation (PRP).

PRVEP was recorded in 21 eyes of 21 patients with proliferative diabetic retinopathy prior to, 1 week after every sessions of laser therapy and 1.5 months after the final treatment. Results were compared between pre and post laser treatment sessions in the study group and paired t-test was used for statistical analysis.

The P100 amplitude showed a significant difference among all treatment sessions with a decreasing trend in the study group after PRP (P<0.001). Also, P100 latency evaluation showed a significant increase after PRP in the study group in all post-PRP sessions (P<0.05). However, 1.5 months after laser treatment, an increase in amplitudes (P<0.001) and a decrease in latencies (P<0.001) of PRVEP were observed and the magnitudes of the parameters approximately returned to their baseline values.

Although decreasing changes in the amplitude and increasing changes in the latency of PRVEP were observed after laser treatment in proliferative diabetic retinopathy patients, one and a half months after the completion of laser therapy, partial recovery of these parameters values was observed.