Wyburn-Mason syndrome, or racemose angioma, is a nonhereditary arteriovenous malformation of the eye and brain, typically involving the optic disc or retina and the midbrain. Skin lesions are present in a minority of cases. The complete syndrome is considerably less common than an isolated occurrence of similar ocular or intracranial disease.
Seizures, mental changes, hemiparesis, and papilledema may result from the CNS lesions, which are frequently a source of hemorrhage, unlike the hemangioma of SWS.
Ocular manifestations are unilateral and congenital but may progress somewhat during childhood. The typical lesion consists of markedly dilated and tortuous vessels that shunt blood flow directly from arteries to veins; these vessels do not leak fluid (Fig 27-14). Vision ranges from normal to markedly reduced in the involved eye, and intraocular hemorrhage and secondary neovascular glaucoma are possible complications. No treatment is indicated for primary lesions.