Quantitative assessment of the visibility of unmyelinated corneal nerves in leprosy.

Unmyelinated corneal nerves were counted in 383 leprosy patients whose eyes looked normal on clinical examination and in an equal number of healthy controls. Visibility of these nerves was decreased significantly (p < 0.01) in the nasal half of the cornea in both patients and controls. There was a significant (p < 0.01) inverse correlation between age and the visibility of these nerves in patients and controls. There was a significant (p < 0.05) reduction in the visibility of these nerves as the spectrum of the disease moved from the tuberculoid to the lepromatous pole. There was no significant correlation between visibility of these nerves and the smear positivity of the patient. Neither did duration of the disease nor the duration of antileprosy treatment alter the visibility of these nerves significantly. Overall, there was a reduction in the visibility of these nerves in patients who had had leprosy reactions.