Corneal irregular astigmatism after hyperopic laser in situ keratomileusis.
OBJECTIVE
To evaluate the changes in irregular astigmatism after hyperopic laser in situ keratomileusis (LASIK).


METHODS
In a prospective case series, 15 eyes of 12 patients who had hyperopic LASIK were evaluated. Corneal topography was obtained before and after hyperopic LASIK. Corneal irregular astigmatism (asymmetry and higher-order irregularity) was calculated using Fourier harmonic analysis of the topography data.


RESULTS
Hyperopic LASIK significantly increased the asymmetry component at 3 (P = 0.0085) and 6 months (P = 0.0307) postoperatively. The mean higher-order irregularity was not significantly changed at any postoperative time-point (P = 0.222). The achieved change in the spherical equivalent was significantly correlated with the post/preoperative ratio of asymmetry (R = 0.695, P = 0.0030).


CONCLUSIONS
Hyperopic LASIK significantly increases the asymmetry component of the cornea, which is correlated with the achieved change in the spherical equivalent.
Amano
Shiro
S
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan. amanos-tky@umin.ac.jp
Nanba
Atsuko
A
Hamada
Naoki
N
Oshika
Tetsuro
T
Uno
Toshihiko
T
Toshino
Atsuko
A
Ohashi
Yuichi
Y
D000328:Adult; D001251:Astigmatism / Q000175:diagnosis / Q000209:etiology*; D003315:Cornea / Q000473:pathology / Q000601:surgery; D003316:Corneal Diseases / Q000175:diagnosis / Q000209:etiology*; D019781:Corneal Topography; D005260:Female; D005583:Fourier Analysis; D006801:Humans; D006956:Hyperopia / Q000601:surgery*; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies