Visual evoked potentials after panretinal photocoagulation in patients with proliferative diabetic retinopathy

PURPOSE: 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). METHODS: 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. RESULTS: 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. CONCLUSION: 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.