Arteriolar occlusive diseases of the macula.

Occlusion of retinal precapillary arterioles may be related to vascular endothelial damage, embolization, vasculitis, and other factors. Following acute retinal precapillary arteriolar occlusion in the macular area, inhibition of axoplasmic transport results in the formation of cotton-wool patches. A variable loss of retinal function occurs. During the subacute phase, reperfusion of the vascular bed is usually seen with a gradual fading of the cotton-wool patch. In the chronic phase, the only sign of the infarction may be a loss of inner retinal substance with an irregularity of the light reflex from the internal limiting membrane, the retinal depression sign. The characteristics of retinal precapillary arteriolar occlusions are reviewed and specific features of hypertensive retinopathy, talc retinopathy, and sickle cell retinopathy are discussed.