Corneal sensitivity and ocular surface health in patients undergoing femtosecond LASIK retreatment for residual refraction.

Abstract

To assess corneal sensitivity and the ocular surface in patients undergoing primary femtosecond laser in situ keratomileusis (FS-LASIK) and those undergoing FS-LASIK retreatment under the same flap due to residual refractive error. Ekol Eye Hospital, Izmir, Turkey. Prospective case series. 19 patients with previous FS-LASIK who had myopic and astigmatic refractive error were included in the study group, and 19 age-matched and sex-matched patients undergoing FS-LASIK for the first time as the control group. Corneal sensitivity, Schirmer test, tear film break-up time (TBUT), Oxford grading scheme for ocular surface staining, and Ocular Surface Disease Index (OSDI) were measured preoperatively and at postoperative 1 week and 1, 3, and 6 months. The mean refractive correction in the study and control groups, respectively, was 2.18 ± 0.78 diopters (D) (range: 1.00 to 3.50) and 2.76 ± 1.20 D (range: 1.00 to 4.50; P = .07). Corneal esthesiometry results in the study and control groups, respectively, were 6.10 ± 12.55 vs 9.90 ± 11.50 mm at 1 week ( P = .001), 41.95 ± 6.98 vs 45.09 ± 5.88 mm at 1 month ( P = .004), 56.09 ± 3.37 vs 56.19 ± 2.52 mm at 3 months ( P = .8), and 58.60 ± 2.01 vs 58.80 ± 1.39 mm at 6 months ( P = .5). Significant difference between the 2 groups in Schirmer test score that disappeared at postoperative 3 months and in TBUT and ocular surface staining that disappeared at 6 months, whereas the statistically significant difference in OSDI score persisted at 6 months ( P = .03) was detected. Corneal surface sensitivity and ocular surface health are more impaired in patients undergoing FS-LASIK retreatment due to residual refractive error.