Corneal sensitivity after photorefractive keratectomy and laser in situ keratomileusis for low myopia

PURPOSE: To evaluate and compare the recovery of postoperative corneal sens itivity after laser in situ kerato-mileusis and photorefractive keratectomy for the correction of low myopia. METHODS: In a prospective study, 17 consecutive eyes (17 patients) underwen t laser in situ keratomileusis to correct myopia ranging from -3.25 to -6.7 5 diopters, and another 18 consecutive eyes (18 patients) underwent photore fractive keratectomy to correct myopia from -3.12 to -7.00 diopters, Cornea l sensitivity was tested preoperatively and I week and 1, 3, and 6 months p ostoperatively using the Cochet-Bonnet esthesiometer. Corneal sensitivity w as tested at the center of the cornea, and in four additional central point s 2 mm from the corneal center (nasal, inferior, temporal, and superior). RESULTS: Corneal sensitivity after laser in situ keratomileusis was reduced at the ablated zone during the first 3 months after surgery (Wilcoxon rank sum test, P < .05), and only after 6 months it returned to its preoperativ e values. However, corneal sensitivity recovered its preoperative values 1 month after photorefractive keratectomy (Wilcoxon rank sum test, P > .05), except for the central corneal point, where 3 months were required. Compari ng both groups, corneal sensitivity was more depressed after laser in situ keratomileusis than after photorefractive keratectomy during the first 3 mo nths (Mann-Whitney test, P < .05), except fur the nasal central point, alth ough no differences were found between both groups at 6 months (P > .05). CONCLUSIONS: In the correction of low myopia, cor neal sensitivity at the a blated zone was more depressed after laser in situ keratomileusis than afte r photorefractive keratectomy during the first 3 months after surgery. Only after 6 months were corneal sensitivity values similar in both groups. (C) 1999 by Elsevier Science Inc. All rights reserved.