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Pediatric Neurovascular Disorders

Both the afferent and efferent visual systems may be affected by vascular disorders arising in the orbital or intracranial compartments. Children may have congenital lesions of the anterior orbit or eyelid that cause ptosis and amblyopia, whereas deeper lesions may become symptomatic only with illness or effort that results in lesion expansion. Typical entities include arteriovenous malformations (AVMs), cavernous angiomas, venous malformations, and lymphangioma. Cerebrovascular abnormalities may affect the visual pathways and indeed may be discovered because of the visual problems they create; as in the orbit, both high-flow (AVM) and no-flow or low-flow (venous malformation) anomalies may be found. Many of these vascular malformations are difficult to treat definitively despite recent advances in both percutaneous intervention and minimally invasive surgical techniques. In contrast, acquired vascular disorders often will have a defined precipitating event that will help the ophthalmologist and other physicians devise a suitable treatment strategy. Radiation therapy for malignancy in particular is associated with aneurysm formation and vasoocclusive disease with spontaneous collateralization (moyamoya disease). This chapter covers both congenital and acquired lesions of the orbital and intracranial circulation and their defining features.