Effect of laser in situ keratomileusis correction on contrast visual acuity.
OBJECTIVE
To evaluate the changes in contrast visual acuity (CVA) based on the amount of myopic correction with laser in situ keratomileusis (LASIK).


METHODS
In this prospective study, patients with myopia ranging from -2.0 to -14.0 diopters (D) were divided into 2 groups: those with myopia less than -6.0 D (n = 20) and those with myopia greater than -6.0 D (n = 13). The CVA was measured preoperatively and 1 week and 1 and 3 months postoperatively using Variable Contrast Visual Acuity Charts.


RESULTS
The patients with less than -6.0 D of myopia had a CVA decrease of 15% 1 week postoperatively, which recovered by 1 month, and a decrease of 2.5% 1 week and 1 month postoperatively, which recovered by 3 months. The patients with more than -6.0 D of myopia had a decrease of 15% and 2.5% at all postoperative times.


CONCLUSIONS
After LASIK to correct myopia of greater than -6.0 D, there may be a persistent decrease in intermediate and low CVA. Patients should be informed preoperatively of this possible decrease in CVA.
Department of Ophthalmology, Tokyo Dental College, Chiba, Japan. up4k-nkmr@asahi-net.or.jp
K
K
Nakamura
H
H
Bissen-Miyajima
I
I
Toda
Y
Y
Hori
K
K
Tsubota
D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D003319:Corneal Stroma / Q000601:surgery*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D011446:Prospective Studies; D014792:Visual Acuity / Q000502:physiology*