outcomes of photorefractive keratectomy for post penetrating keratoplasty myopia and astigmatism

purpose: 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). methods: thirty-eight eyes of 32 patients underwent prk with mmc to correct astigmatism and myopia following pkp. result: mean spherical equivalent (se) was -5.2±4.7 d (diopter) and mean astigmatism was -2.4±3 d pre-operatively 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. conclusion: 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.