Diagnostic Criteria for Leber's Congenital Amaurosis

To the Editor. —I am concerned by the lack of specific diagnostic criteria in a recent article by Schroeder et al, 1 which retrospectively reveiwed the cases of 43 patients with Leber's congenital amaurosis. For example, the authors stated that all patients "presented with poor vision since birth or before 6 months of age" but did not specify what they considered to be "poor" vision. The authors also did not state the age at which the patients were first examined. The fact that many of the patients had cataracts, keratoconus, and strabismus suggests that they were not examined at an early age. Although a "family history" was obtained, no data concerning the family history of these patients were presented. The diagnosis of Leber's congenital amaurosis is based on the findings of an extinguished electroretinographic response to light and congenital blindness. Six of the patients in the study by Schroeder et