[Outcomes of photorefractive keratectomy for post penetrating keratoplasty myopia and astigmatism]

To report the results of photorefractive keratectomy [PRK] with mitomycin-C [MMC] to correct myopia and astigmatism in patients who had previously undergone penetrating keratoplasty [PKP]. Thirty-eight eyes of 32 patients underwent PRK with MMC to correct astigmatism and myopia following PKP. Mean spherical equivalent [SE] was -5.2 +/- 4.7 D [diopter] and mean astigmatism was -2.4 +/- 3 D preoperatively which reached -3.1 +/- 3.1 D and -1.2 +/- 2.8 D 3 months after the operation respectively. The cornea was clear in 55.3%, had trace haze in 21.1%, moderate haze in 15.8% and severe haze in 7.9% of cases. PRK with MMC after PKP is a relatively safe and effective procedure. It reduces both the spherical error and the cylindrical component of the ametropia. Corneal haze is the major complication

[Comparison of aberrations after photorefractive keratectomy using tissue saving and personalized techniques]

To compare the effects of standard tissue saving method and personalized techniques of photorefractive keratectomy [PRK] on aberration changes in fellow eyes. This randomized controlled trial was performed on patients who were referred to Isfahan Parsian Clinic during 2007. After a comprehensive ophthalmologic examination, PRK was randomly performed using tissue saving [TS] technique in one eye and personalized [P] technique in the fellow eye. Aberrometry was performed pre- and 6 months postoperatively. This study included 296 eyes of 148 [67 male and 81 female] patients with mean age of 29.1 +/- 7.0 years. The two groups had no significant difference in terms of laterality, pupil size and level of myopia preoperatively [P=0.65]. Uncorrected visual acuity was 20/25 or more in 88.9% of the TS group and 92.6% of the P group [P=0.83]. Mean refractive error 6 months postoperatively was -0.50 +/- 0.36 diopter [D] in the TS group and 0.31 +/- 0.43 D in the P group [P=0.95]. Mean root-mean-square [RMS] value was -0.41 +/- 0.17 preoperatively and 0.86 +/- 0.43 postoperatively in the group TS [P<0.01]. Corresponding figures were 0.47 +/- 0.39 and 0.77 +/- 0.43 in the P group [P<0.01]. The two groups did not differ regarding pre- and postoperative RMS. Postoperative aberrations may be increased with both tissues saving and personalized techniques of PRK with no significant difference between them in this regard