Time course of refractive and corneal astigmatism after laser in situ keratomileusis for moderate to high astigmatism.

PURPOSE: To assess the time course of refractive and corneal astigmatism after laser in situ keratomileusis (LASIK) in eyes with moderate to high astigmatism.

SETTING

Department of Ophthalmology, Kitasato University, Kanagawa, Japan.

DESIGN

Retrospective case series.

METHODS

Keratometric readings and corneal astigmatism were determined with an autokeratometer in consecutive patients who had LASIK for moderate to high astigmatism (≥2.00 diopters [D]).

RESULTS

The study enrolled 48 eyes of 35 patients with a mean age of 34.0 years ± 8.1 (SD), a mean spherical error of -5.10 ± 2.11 D, and a mean cylindrical error of -2.74 ± 0.99 D. Postoperatively, the mean spherical refraction changed significantly from 0.38 ± 0.80 D at 1 week to -0.13 ± 0.90 D at 1 year (P<.001, Wilcoxon signed-rank test). The mean cylindrical refraction showed no significant change (-0.67 ± 0.54 D at 1 week to -0.63 ± 0.63 D at 1 year) (P=.54). There were significant increases in the flattest and steepest keratometry readings at 1 week and at 1 year. However, no significant change in corneal astigmatism was found at either time point (P=.10).

CONCLUSIONS

After LASIK, there was significant refractive regression in the spherical component but not in the cylindrical component. This suggests that refractive regression occurs by corneal steepening in the spherical component and that astigmatic regression does not occur, even in moderately to highly astigmatic eyes.

FINANCIAL DISCLOSURE: No author has a financial or proprietary interest in any material or method mentioned.