Factors influencing corneal involvement in leprosy.

Corneal involvement in leprosy is known to be influenced by factors such as lagophthalmos, ectropion, and corneal anesthesia. In the present study conducted on 400 eyes of leprosy patients, observations were made on tear film abnormalities, and their relation to the above-mentioned factors was analyzed. The abnormality of tear film breakup time (BKUT) was found to be clinically more significant (47.2%) than a Schirmer's test alone (24.5%), and this finding was of greater significance in the lepromatous form of leprosy. An abnormal BKUT reflects a decreased mucin secretion by the conjunctival goblet cells. Tear film abnormalities in association with lagophthalmos, corneal anesthesia, concomitant ocular diseases, and environmental factors such as high relative humidity have been identified as factors contributing to corneal involvement in leprosy in India. It is not surprising that with so many mechanisms of corneal involvement the clinical manifestations are diverse, and all forms of pathological changes may contribute to corneal morbidity.