Excimer laser intrastromal keratomileusis

We studied 30 eyes in 22 patients with severe myopia who underwent myopic keratomileusis combined with excimer laser refractive correction. The goals of the study were to evaluate the efficacy of the procedure in decreasing myopia, to assess the response of the cornea to intrastromal photoablation, and to examine the relationship between the number of laser pulses and the refractive correction achieved. The patients were observed for six months. The technique demonstrated a marked refractive reduction (from 171.875 +/- 3.32 diopters to -2.125 +/- 1.40 diopters) and an excellent corneal response to photoablation. An average decrease of 7.63 diopters was observed in keratometry readings. No marked change in the degree of astigmatism was observed after the procedure. Intrastromal haze was observed biomicroscopically in three of 30 eyes (10%). Postoperative best-corrected visual acuity remained at the preoperative level in 22 eyes (74%), improved in five eyes (16%), and declined in three eyes (10%). At the end of the follow-up period, uncorrected visual acuity was 20/50 or better in three of 30 treated eyes (10%) and 20/100 or better in 25 of 30 treated eyes (83.3%). No intraoperative complications were observed, but the following postoperative complications were seen in seven of 30 (23.2%) eyes: four eyes (13.3%) developed irregular astigmatism, one eye (3.3%) had poor night vision, and two eyes (6.6%) had irregularities in Bowman's membrane. The operation was repeated with homoplastic material in one of the two eyes with Bowman's membrane irregularities after six months, because of central alterations in Bowman's membrane.