[Experimental venous thrombosis: preretinal PO2 before and after photocoagulation].

Experimental occlusion of a retinal vein leads to retinopathy in the affected drainage area. In some cases the formation of ischemic regions, where the retina is completely destroyed, is typical for the development of this retinopathy. Laser photocoagulation restores the physiological preretinal oxygen pressure in these hypoxic regions. It is possible that the rise in O2 pressure which has been observed is caused by destruction of pigment epithelium and the photoreceptor layer, as oxygen diffuses freely from the choroid to the inner retina without being consumed by the outer layers.