[The effects of photocoagulation on the electrical activity of the diabetic retina]

The aim of photocoagulation in diabetic retinopathy is to destroy ischaemic retina because this produces a vasogenic factor, responsible of neovascularization. Retinal burn reduces the number of photoreceptors and effects the transmission of nervous impulse in areas close to those coagulated. It is presumable therefore that electroretinographic parameters will be significantly modified after treatment. 23 diabetic patients where investigated, resulting 43 scotopic electroretinograms, 41 photopic electroretinograms and 46 flicker electroretinograms, each eye being considered separately. The statistic analysis showed significant alterations with laser treatment of the amplitudes of a and b waves in both scotopic and photopic conditions as well as diminished amplitude of the flicker test.