Panretinal photocoagulation and retinal oxygenation.

Panretinal photocoagulation destroys some of the photoreceptors and thereby reduces the oxygen consumption in the outer retina and allows more O2 to flow from the choroid to the inner retina. Measurements of the preretinal oxygen tension were made in rhesus monkeys that had portions of their retinas photocoagulated. With the animal breathing one atmosphere O2, the oxygen tension over photocoagulated areas of retina was significantly higher than the PO2 over normal, untreated areas of retina. It is proposed that the therapeutic effect of panretinal photocoagulation in diabetic retinopathy lies in the oxygenation of the inner retina from the choroid.