Effect of myopic LASIK on human corneal sensitivity.

Objective: To evaluate the changes in corneal sensitivity after LASIK for the correction of different degrees of myopia.

Design: Prospective, nonrandomized, comparative self-controlled trial.

Participants: One hundred two myopic eyes of 58 patients were included in this study.

Methods: The eyes were divided into four groups: group 1, from -0.75 to -3.75 diopters (D); group 2, from -4.00 to -7.75 D; group 3, from -8.00 to -11.75 D; group 4, from -12.00 to -16.00 D. Corneal sensitivity was measured before and 1, 7, 30, 90, 180, 270, and 365 days after surgery or until full recovery.

Main Outcome Measures: The recovery of corneal sensation after LASIK.

Results: Immediately after surgery, the lenticule was found to be completely anesthetic, and the full recovery varied according to the depth of the ablation. Normal levels of corneal sensitivity, but not full recovery, were found after 90 days in groups 1 and 2 and after 180 days in groups 3 and 4. Full recovery of corneal sensitivity was found after 180 days in groups 1 and 2 and after 270 days in groups 3 and 4.

Conclusions: After LASIK, corneal sensitivity is decreased at the central and paracentral areas for as long as 9 months. The depth of the ablation seems to be an important factor in the temporary decrease of corneal sensitivity and its recovery.