Leber's congenital amaurosis (LCA) refers to a group of rare inherited retinal dystrophy characterized by vision loss, often from birth. LCA is the most severe form of all inherited retinal dystrophies. It accounts for at least 5% of all such retinal dystrophies, and is also one of the main causes of blindness in children. The estimated birth prevalence of LCA is two to three per 100,000 births. There are at least 13 types of Leber congenital amaurosis. These types are distinguished by their genetic cause, patterns of vision loss, and related eye abnormalities.
Clinical diagnosis is based on clinical history of failure to develop reactions to visual stimuli, roving eye movements or nystagmus, sluggish pupillary responses and a normal, or less frequently an abnormal fundus on dilated fundoscopy. To date, no definitive treatment or cure for LCA exists.
Stockton et al. (1998) reported a large consanguineous Saudi Arabian kindred segregating Leber congenital amaurosis. In addition to poor visual acuity (typically less than 5/200), affected individuals manifested moderate midfacial hypoplasia with enophthalmos, complex vertical, horizontal, and rotatory nystagmus present from early life, moderate hypermetropic refractive errors with astigmatism, and various presentations of esotropia and exotropia. At least four individuals had hospital-based electroretinograms, which were nonrecordable in both photopic and scotopic components in the first two years of life.