Surgical results of photorefractive keratectomy with different operative modes

Abstract

Purpose To compare the predictability, efficacy, and safety of photorefractive keratectomy (PRK) using different operative modes. Setting National Taiwan University Hospital, Taipei, Taiwan. Methods One hundred fifty-three eyes of 80 patients who had PRK for myopia with a follow-up of at least 6 months were studied. All patients were sequentially assigned to 1 of the following surgical modes: mode 1: PRK with the Summit OmniMed excimer laser; mode 2: PRK with the Summit Apex Plus laser; mode 3: PRK with the Summit Apex Plus laser with anti-central-island pretreatment. Results Six months after treatment, a homogeneous topographic pattern was seen in 76% of mode 1 eyes, 70% of mode 2 eyes, and 88% of mode 3 eyes. In the low myopia group (≤−6.0 diopters [D]), the mean residual refractive error was −0.79 D ± 0.59 (SD) in mode 1, −0.94 ± 1.02 D in mode 2, and −0.31 ± 0.42 D in mode 3. In the high myopia group (>−6.0 D), it was −1.93 ± 1.51 D, −1.54 ± 0.88 D, and −0.70 ± 0.81 D, respectively. Uncorrected visual acuity of 20/25 or better was achieved in 81% of mode 1 eyes, 56% of mode 2 eyes, and 89% of mode 3 eyes in the low myopia group, and in 48%, 28%, and 72%, respectively, in the high myopia group. Conclusions Photorefractive keratectomy appears to be a predictable and effective procedure. The best results were achieved with the Summit Apex Plus laser with anti-central-island pretreatment, followed by the Summit OmniMed laser. The Summit Apex Plus laser without anti-central-island pretreatment produced less satisfactory results.