Ischemia of ciliary arterial circulation from ocular compression.

Two patients developed unilateral central retinal artery and posterior ciliary artery occlusions related to ocular compression during general anesthesia. One patient had evidence of extensive choroidal ischemia with diffuse hypopigmentation, pigmentary mottling of the posterior pole, and disc edema. Electroretinography showed diminution of the A and B waves. The other patient showed patchy choroidal ischemia with subsequent development of wedge-shaped areas of pigmentary atrophy and mottling in the midperiphery. Iridocyclitis and prolonged hypotony were also present. Retinal and posterior ciliary artery occlusion (perhaps at the level of the ophthalmic artery) can occur as a result of ocular compression by a face mask or an improperly positioned headrest. Systemic hypotension is a factor in many cases. Proper positioning of the head on an adequate headrest and avoidance of ocular compression will prevent the occurrence of retinal and choroidal occlusion during general anesthesia.