The surgical removal of a subfoveal choroidal neovascular membrane: an alternative treatment to laser photocoagulation.

Whenever hypoxia occurs as the result of a pathologic condition in or near the highly metabolic retinal tissue, there often is an attempt by the vascular tissue in the area to offset this loss through the development of a neovascular membrane. If the affected tissue is the choroid/retinal pigment epithelium/Bruch's membrane complex, or outer 1/3 of the sensory retina, the source of these new vessels is the choriocapillaris. The vessels in the neovascular membrane are fragile, leak serum profusely and tend to hemorrhage. The natural history of these choroidal neovascular membranes (CNVMs), when they are located in the center of the macula, is the formation of a disciform scar resulting in the severe loss of central vision (20/200 or worse). Laser photocoagulation has been successful in treating neovascular membranes and limiting visual loss when they have been either extrafoveal, i.e., no closer than 200 mu o to the center of the foveal avascular zone (FAZ), or juxtafoveal, i.e., no closer than 1 mu o to the center of the FAZ. Until recently, laser treatment of subfoveal CNVMs was not considered an acceptable option due to its destructive effects on foveal vision. The surgical removal of subfoveal neovascular membranes has been recently described as an attempt to spare more vision.