Topography-driven photorefractive keratectomy: results of corneal interactive programmed topographic ablation software.

Abstract

This study evaluated the efficacy, predictability, stability, and safety of a software program (Corneal Interactive Programmed Topographic Ablation (CIPTA) LIGI, Taranto, Italy) which, by transferring programmed ablation from the corneal topography to a flying-spot excimer laser, provides customized laser ablation. Noncomparative consecutive case series. Forty-two eyes of 34 subjects with a mean age of 33.9 (range, 20-54) had CIPTA at the Cattedra di Ottica Fisiopatologica of Bari (Italy). Twenty-eight eyes were treated for hyperopic astigmatism and 14 for myopic astigmatism. All the subjects had irregular astigmatism. OPERATION: Topography was acquired by a corneal topography mapping system (Orbscan, Orbtek, Inc., Salt Lake City, UT). These data were processed to obtain a customized altimetric ablation profile, which was transferred to a flying-spot laser (Laserscan 2000, Lasersight, Orlando, FL). Data on uncorrected (UCVA) and best-corrected visual acuity (BCVA), predictability, and stability of refraction and any complications were analyzed. Mean follow-up was 13.2 months. At the last postoperative examination, 26 eyes (92.8%) in the hyperopic group and 12 eyes (85.7%) in the myopic group had an UCVA superior to 20/40. Twelve hyperopic eyes (42.8%) and five myopic eyes (35.7%) had a UCVA of 20/20. All patients fell between 1 diopter of attempted correction in the spherical equivalent. Only 1 (2.4%) of the 42 eyes, belonging to the hyperopic group, lost 1 Snellen line of BCVA. We did not observe any decentration and/or haze after photorefractive keratectomy treatment or any irregularity in the flap-stroma interface in the three laser in situ keratomileusis operations performed in this study. The combination of topographic data with computer-controlled flying-spot excimer laser ablation is a suitable solution for correcting irregular astigmatism due to different causes.