Spontaneous dural carotid-cavernous fistula with central retinal vein occlusion and iris neovascularization. Spontaneous dural carotid-cavernous fistulas are dural vascular malformations that usually run a benign course. We present a case of a spontaneously occurring dural carotid-cavernous fistula complicated by central retinal vein occlusion and iris neovascularization that led to progressive visual failure. 