Familial Exudative Vitreoretinopathy (FEVR)
FEVR is a hereditary condition where the retinal blood vessels do not develop normally. As a result, scar tissue may develop which—as it contracts—can detach the retina and result in visual loss.
Vision loss may also occur as a result of abnormal leaking blood vessels (exudation), and a progressive shutdown of the finest blood vessels in the eye (capillary dropout) critical for the delivery of oxygen to the retinal cells.
FEVR does not always result in vision loss, and carriers of the disease may have no visual symptoms—only to be diagnosed when there is an affected family member. Wide-field fluorescein angiography (a photographic test using an intravenous dye to provide detailed information about the structure and function of retinal blood vessels) is critical for the diagnosis and management of FEVR.
Vision loss is the most common FEVR-related symptom. In mildly to moderately affected individuals, crossed eyes (strabismus) and “lazy eye” (amblyopia) are often encountered.
