Ophthalmic Ischemia Secondary to Moyamoya Syndrome in Neurofibromatosis Type 1

Moyamoya is a syndrome described of stenosis of the large intracerebral arteries and resultant formation of fine vascular collateral vessels at the base of the brain. Ischemia results from hyperplasia of smooth muscle cells and luminal thrombosis of the proximal internal carotid arteries thereby affecting the middle and anterior cerebral and ophthalmic arteries. Moyamoya exists as a primary or secondary disorder from a variety of etiologies including Neurofibromatosis type I (NF1), as illustrated in the following case. Ophthalmologic manifestations of Moyamoya include morning glory disc anomaly, optic nerve hypoplasia, chorioretinal coloboma, sphenopharyngeal meningocele, ocular ischemic syndrome, anterior ischemic optic neuropathy, and central retinal vein and artery occlusions.