[Leber congenital amaurosis: diagnosis, follow-up and differential diagnosis]

Leber's congenital amaurosis (LCA) had been diagnosed on/in 42 children between 1968 and 1996 at the Deptm. of Ophthalmology, University Hospital Zurich. We reexamined critically this rare diagnosis in retrospect and with new examinations where possible.

Clinical and electroretinographic (ERG) results, often obtained in general anesthesia, were re-evaluated and when possible repeated in new examinations.

Thirty-three of the total 42 patients presented with an extinguished, 35 with markedly reduced, and 6 with minimal ERGs. A profound visual loss (from no light perception to 20/200), nystagmus and strabismus were the principal symptoms. The heterogeneity of retinal findings ranged from normal to salt and pepper or bone spicules pigmentation and pronounced chorioretinal atrophy. Vascular attenuation and rarification were frequent. Patients with nonocular findings such as mental retardation (n = 12), renal (n = 3) and skeletal (n = 4) abnormalities revealed no differing ERG- or retinal findings. The oculodigital sign (eye-poking) was found in 25%, and parental consanguinity was evident in 10% of the cases. In 16 patients that were reexamined, the progression of the disease was characterized by an increase in retinal pigmentary changes, attenuation of retinal vessel, and further diminuation of the visual acuity (n = 6).

Upon review, the diagnosis had to be revised in 8 patients as juvenile retinitis pigmentosa and in one as infantile Refsum syndrome. Bilateral visual impairement in infants should be assessed clinically and electroretinographically within the first year. Neuropediatric and metabolic examinations meaningfully complement the diagnostic procedures.