Pathogenesis of dry eye in leprosy and tear functions.

Seventy-five leprosy patients and an equal number of age- and sex-matched controls were examined for tear functions, using Schirmer's test and tear break up time (BUT). There was no statistically significant difference in the Schirmer's test, but the tear BUT showed a statistically significant lower value of < 10 seconds in multibacillary patients compared to paucibacillary patients. Leprosy patients with lagophthalmos and decreased corneal sensation showed a lower value of tear BUT which was also statistically significant. This study shows that even though the quantity of tears is not affected, proper and prolonged wetting of the cornea is deficient in many leprosy patients.