title: Photorefractive keratectomy in the correction of astigmatism using Schwind Amaris 750s laser.
abstract: OBJECTIVE
  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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Department of Ophthalmology, Beyoglu Eye Research and Education Hospital, Istanbul, Turkey.
authors.forename: Okkes
authors.initials: O
authors.lastname: Baz
authors.forename: Necip
authors.initials: N
authors.lastname: Kara
authors.forename: Ercument
authors.initials: E
authors.lastname: Bozkurt
authors.forename: Engin Bilge
authors.initials: EB
authors.lastname: Ozgurhan
authors.forename: Alper
authors.initials: A
authors.lastname: Agca
authors.forename: Kemal
authors.initials: K
authors.lastname: Yuksel
authors.forename: Yavuz
authors.initials: Y
authors.lastname: Ozpinar
authors.forename: Ahmet
authors.initials: A
authors.lastname: Demirok
keywords: astigmatism; mitomycin-C; photorefractive keratectomy; trans-photorefractive keratectomy