Photorefractive keratectomy in the correction of astigmatism using Schwind Amaris 750s laser

AIM: To evaluate the results of three photorefractive keratectomy (PRK) procedures in the treatment of astigmatism. METHODS: In this retrospective comparative case series, 89 eyes of 50 patients who underwent PRK treatment for astigmatism were enrolled. The patients were divided into 3 groups based on the PRK procedure: Group 1: PRK without mitomycin-C (MMC) application, Group 2: PRK with MMC application, and Group 3: Trans-Photorefractive Keratectomy (T-PRK). The efficacy, safety, predictability, and complications of treatment were assessed at 1, 3 and 6 months after the treatment. RESULTS: At postoperative 6 months, the percentage of postoperative uncorrected visual acuity (UCVA) of 20/20 or better was 55.6% (20 eyes) in group 1, 75% (15 eyes) in group 2, and 75.8% (25 eyes) in group 3 (P=0.144). The percentage of postoperative best corrected visual acuity (BCVA) of unchanged or gained >= 1 lines was 80.6% (29 eyes) in group 1, 70% (14 eyes) in group 2, and 90.9% (30 eyes) in group 3 (P=0.151). The percentage of postoperative BCVA of lost >= 2 lines was 11.1% (4 eyes) in group 1, 20% (4 eyes) in group 2, and 6.1% (2 eyes) in group 3. The mean manifest refractive spherical equivalent (MRSE) and mean cylindrical refraction were not significantly different among the each groups (P>0.05). At postoperative 6 months, the percentage of MRSE of within +/- 0.50 D was 100% (36 eyes) in Group 1, 100% (20 eyes) in Group 2, and 93.9% (31 eyes) in Group 3. At the each follow-up period, there was no significant difference in number of eyes with haze and mean haze score(P>0.05). CONCLUSION: The study showed that PRK without MMC, PRK with MMC and T-PRK appears to have similar effectiveness, safety and predictability in the treatment of astigmatism. The incidence of haze was also similar between the three groups.