Electrophysiological studies before and after argon-laser photocoagulation in diabetic retinopathy.

50 eyes with diabetic retinopathy were studied before and after treatment with argon-laser coagulation. After treatment, decreases of the L/D ratios of the EOGs and of the amplitudes of all ERG components were found. The scotopic b waves were more involved than the photopic b waves. The peak times were hardly modified. The dark-adaptation curves were not modified. Interesting was the fact that in the pretreatment findings the EOGs were involved before the ERGs. The decreases of the L/D ratios started when avascular and ischemic zones were seen on fluorescein angiography.