Leber's congenital amaurosis

Leber's congenital amaurosis

[lā′bərz]

Etymology: Theodor von Leber, German ophthalmologist, 1840-1917; L, congenitus, born with; Gk, amauroein, to darken

a rare kind of blindness or severely impaired vision caused by a defect transmitted as an autosomal-recessive trait and occurring at birth or shortly thereafter. The eyes appear normal externally, but pupillary constriction to light is sluggish or absent, and electroretinographic responses are decreased or absent. Pendular nystagmus, photophobia, cataract, and keratoconus may be present; the ophthalmic disorder may be associated with mental retardation and epilepsy. One type of Leber's amaurosis results in complete blindness. In a second kind the pathology does not progress, and the patient has very mild vision loss.

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amaurosis [am″aw-ro´sis]

loss of sight without apparent lesion of the eye, as from disease of the optic nerve, spine, or brain.

amaurosis conge´nita (amaurosis congenita of Leber) (congenital amaurosis) hereditary blindness occurring at or shortly after birth, associated with an atypical form of diffuse pigmentation and commonly with optic atrophy and attenuation of the retinal vessels.

amaurosis fu´gax sudden temporary or fleeting blindness.

Leber's congenital amaurosis amaurosis congenita.

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Leber's congenital amaurosis

A hereditary, bilateral blindness present at birth or in early childhood. It is caused by mutations in the gene encoding the retinal guanylate cyclase (GUCY2D) on chromosome 17. Initially, the ocular fundus appears normal, although the ERG is markedly reduced. A salt and pepper fundus and optic atrophy appear later. The condition is often accompanied by nystagmus and photophobia.