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


METHODS
Department of Ophthalmology, Kitasato University, Kanagawa, Japan.


METHODS
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.


BACKGROUND
No author has a financial or proprietary interest in any material or method mentioned.
Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan. iki0478@yahoo.co.jp
Akihito
A
Igarashi
Kazutaka
K
Kamiya
Kimiya
K
Shimizu
Mari
M
Komatsu
D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D003315:Cornea / Q000503:physiopathology*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011184:Postoperative Period; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D013997:Time Factors; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult