Effect of photorefractive keratectomy and laser in situ keratomileusis in high myopia on logMAR visual acuity and contrast sensitivity.
OBJECTIVE
To compare effect of photorefractive keratectomy (PRK) and laser in situ keratomileusis (LASIK) on contrast sensitivity (CS) and best corrected visual acuity (BCVA) in high myopia.


METHODS
38 myopes (PRK) and 31 patients (LASIK) were examined before and 1, 3, 6, and 12 months postoperatively. Mean preoperative spherical equivalent was -8.0 +/- 1.7D (PRK) and -9.2 +/- 2.1D (LASIK). CS was tested on a computerized system of the Contrast Sensitivity 8010 Type at 6 spatial frequencies (0.74 and 29.55 c/deg), BCVA was measured on logMAR charts.


RESULTS
At 12 months postoperatively, mean spherical equivalent was -0.6 +/- 1.0D (PRK) and -1.0 +/- 0.8D (LASIK). Postoperative values of CS were significantly higher in the PRK group, except for spatial frequencies of 3.69 and 7.39 c/deg up to 3 months postoperatively. The initial significant decrease of BCVA lasted up to 6 months after PRK. In the LASIK group BCVA was not significantly different from its preoperative level at the 3-months follow-up.


CONCLUSIONS
The significant improvement of CS after PRK suggest that PRK can improve quality of vision in eyes with high myopia. Although recovery of BCVA after LASIK was faster than after PRK, there may be a persistent decrease in CS.
University Hospital in Hradec Králové, Department of Ophthalmology, Czech Republic. langrovah@lfhk.cuni.cz
Hana
H
Langrová
Matthias
M
Derse
Dagmar
D
Hejcmanová
Alena
A
Feuermannová
Pavel
P
Rozsíval
Markéta
M
Hejcmanová
D015350:Contrast Sensitivity; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy; D012029:Refraction, Ocular; D014792:Visual Acuity