This study comprises 53 eyes, divided into two groups A and B, with proliferative diabetic retinopathy which were treated with panretinal photocoagulation (PRP). Its purpose is to investigate the alterations in the central 15° and 30° of the visual field and in each quadrant separately. In both groups A and B, PRP covered the periphery and midperiphery. In group A, it stopped 2 disc diameters (DD) from the upper temporal and lower margin of the fovea including the papillomacular bundle, while in group B, PRP stopped 3 DD from the upper temporal and lower margin of the fovea and 1 DD of the nasal margin of the optic disc. The investigation revealed, in group B after PRP, an improvement of the retinal sensitivity in the central 15° of the visual field (p < 0.01). In the 30° of the visual field a deterioration after PRP was noted in both groups A and B, the deterioration being however much more prominent in group A. Comparing the results between groups B and A after PRP, a difference in the retinal sensitivity in favour of group B at 15° and 30° of the visual field was found. As regards regression of neovascularization and visual acuity, no statistically significant difference has been observed between the two groups.