Contributor: Gordon K. Klintworth
Atherosclerosis is an extremely common disorder of the cardiovascular system characterized by the deposition of lipid within the endothelial lining. It may involve almost any artery and especially the coronary arteries [atherosclerosis - coronary artery], carotid artery, and aorta. Risk factors for atherosclerosis include age, gender, hypercholesterolemia (especially LDL cholesterol), cigarette smoking, diabetes mellitus, physical inactivity, and genetic influences. Persons with certain disorders of lipid metabolism (familial hypercholesterolemia, cerebrotendinous xanthomatosis, apolipoprotein E deficiency) are prone to premature atherosclerosis, but there is no increased risk of atherosclerosis in patients with Fish-eye disease or Norum disease. Coronary heart disease is associated more with the total cholesterol: HDL cholesterol ratio than with the HDL level alone. Complications of atherosclerosis include myocardial infarction, stroke, and embolism. Ophthalmic manifestations of atherosclerosis include central retinal artery occlusion and the effects of occlusovascular disease. These may result from carotid artery insufficiency as well from retinal embolism [embolization - retina] derived from a thrombus over an atherosclerotic plaque or a infacted cardiac muscle [cardiac mural thrombus]. The lumen of the central retinal artery may become totally or partially occluded by an atherosclerotic plaque usually at the lamina cribrosa. Atherosclerosis within the central retinal artery may extend into the main branches of the central retinal artery near the optic nerve head, and even into more distant branches. An acute central retinal artery occlusion may be preciptipated by hemorrhage beneath an atheromatous plaque. Atherosclerosis within the central retinal artery may extend into the main branches of the central retinal artery near the optic nerve head, and even into more distant branches. An acute central retinal artery occlusion may be preciptipated by hemorrhage beneath an atheromatous plaque. When the central retinal artery becomes occluded the inner retina becomes ischemic and pale and the resultant retinal ischemia eventually causes atrophy of the inner retinal layers. With the loss of retinal ganglion cells the axons of the retinal ganglion cells degenerate, the nerve fiber layer of the retina becomes atrophic and the optic nerve undergoes degenerative changes leading to optic atrophy.