Clinical and Genetic Studies of Familial Exudative Vitreoretinopathy

This study will examine the extent of the vision problem in familial exudative vitreoretinopathy (FEVR) and try to identify the genes responsible for this hereditary eye disorder. Patients with FEVR have incomplete formation of blood vessels in the periphery of the retina (the inner part of the eye that is responsible for vision). As a result, abnormal vessels can form and retinal detachment and vitreous bleeding can occur, causing significant vision loss. Vision loss usually begins in childhood, gradually worsening over time. Some patients eventually become blind. Patients of all ages with FEVR and their family members may be eligible for this study. Participants undergo the following tests and procedures: * Family history, especially regarding eye disease. A family tree is drawn. * Blood draw for genetic testing related to FEVR. * Eye examination to assess visual acuity (eye chart test) and eye pressure, and to examine pupils, lens, retina and eye movements. The pupils are dilated with drops for this examination. * Fluorescein angiography to evaluate the eye's blood vessels. A yellow dye is injected into an arm vein and travels to the blood vessels in the eyes. Pictures of the retina are taken using a camera that flashes a blue light into the eye. The pictures show if any dye has leaked from the vessels into the retina, indicating possible blood vessel abnormality. * Patients affected with FEVR will also undergo DEXA scan to look for osteoporosis. X-rays are used to scan the hip, forearm and spine for bone density measurements.