Effects of reference axes used during measurements of ocular and corneal higher-order aberrations in patients following LASIK.
OBJECTIVE
To determine the effects of the reference axes used during the measurements of ocular and corneal higher-order aberrations (HOAs) in patients before and after laser in situ keratomileusis (LASIK).


METHODS
Wavefront sensing and corneal topography were determined for 29 eyes of 15 patients before and after LASIK. Ocular and corneal HOAs were calculated for 4-mm- and 6-mm-diameter pupils with the instrument aligned with the line of sight (LOS) or with the vertex normal (VN).


RESULTS
For ocular HOAs after surgery, the spherical-like aberration was significantly larger when the VN axis rather than the LOS axis was used for pupils of both diameters. For corneal HOAs before surgery, in addition to the larger spherical-like aberration for VN, coma-like aberrations were significantly larger with LOS than with VN for both pupil diameters. For corneal HOAs after surgery, the spherical-like aberrations and total HOAs for 4-mm-diameter pupils with VN were significantly larger than those with LOS.


CONCLUSIONS
The HOAs were significantly different depending on the axes used and should be described on the basis of a common axis. These results suggest that the anterior surface of the normal or post-LASIK cornea is more rotationally symmetrical along the VN than along the LOS.
Takehara
Atsuko
A
Department of Ophthalmology, Osaka University Medical School, Suita, Osaka, Japan.
Maeda
Naoyuki
N
Department of Ophthalmology, Osaka University Medical School, Suita, Osaka, Japan. nmaeda@ophthal.med.osaka-u.ac.jp.
Ninomiya
Sayuri
S
Department of Applied Visual Science, Osaka University Medical School, Suita, Osaka, Japan.
Fujikado
Takashi
T
Department of Applied Visual Science, Osaka University Medical School, Suita, Osaka, Japan.
Hiroha
Yoko
Y
Topcon Corporation, Tokyo, Japan.
Mihashi
Toshifumi
T
Topcon Corporation, Tokyo, Japan.
D000328:Adult; D001251:Astigmatism / Q000209:etiology / Q000473:pathology*; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D019781:Corneal Topography / Q000379:methods*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery