Congenital corneal anesthesia: problems in diagnosis.

Congenital corneal anesthesia (CCA) is a rare clinical entity that presents a whole gamut of problems before lending itself to a diagnosis by the clinician. Not recognizing the history of self-inflicted corneal injuries, not evaluating the corneal sensations in a child with recurrent corneal ulceration, misdiagnosis of such cases as viral keratitis, and not ruling out all the secondary causes of corneal anesthesia, as well as the other causes of self-inflicted injuries, are some of the pitfalls in the diagnosis of congenital corneal anesthesia. Four cases representative of different aspects of CCA are presented. The problems in the diagnosis of these cases are discussed. A clinical classification of congenital corneal anesthesia is suggested and the systemic anomalies associated with this disorder are enumerated.