Leber congenital amaurosis--differential diagnosis, ophthalmological and neuroradiological report of 18 patients.

Between 1985 and 1995 eighteen babies, presenting to our department with absent visual contact and roving eye movements, showed a non-recordable flash electroretinogram (fERG). This was confirmed when repeated after a one-year interval. In four patients with developmental delay an underlying systemic disorder was diagnosed after a thorough pediatric neurological evaluation: Senior Loken syndrome, neuroaxonal dystrophy, ceroid lipofuscinosis and a yet unclear metabolic disorder were the revised diagnoses. The fourteen remaining patients were diagnosed as having primary idiopathic Leber Congenital Amaurosis (LCA). Three of them showed developmental delay. In all three cerebellar abnormalities were visualized on brain computed tomography (CT) and/or magnetic resonance imaging (MRI). Brain CT of the other eleven patients with age appropriate development was normal. We conclude that LCA is a diagnosis of exclusion and a cautious approach with a thorough history and pediatric neurological examination is necessary to exclude a more global pediatric neurological disorder.