Early clinical experience using custom excimer laser ablations to treat irregular astigmatism

Purpose: To assess the viability of custom excimer laser ablations for trea ting irregular astigmatism. Setting: Single-center prospective study of a new custom-ablation technique . Methods: Twelve patients received 15 custom ablations for irregular astigma tism resulting from keratoconus, penetrating keratoplasty for keratoconus, prior decentered laser in situ keratomileusis, or incisional refractive sur gery. Follow-up ranged from 6 weeks to 14 months. initially, the laser beam was manually decentered; later, the Contoured Ablation Patterns (CAP) meth od (VISX, Inc.) was used to automatically decenter the ablation over the co rneal elevation. Results: Results are presented in a case-by-case fashion. In the manual dec entration group, the uncorrected visual acuity (UCVA) was 20/50 or better i n 9 of 11 eyes (81.8%) and 20/40 or better in 7 eyes (63.6%). Surgery resol ved or decreased visual symptoms when present. The best corrected visual ac uity (BCVA) was maintained or improved in all eyes. Persistent less than or equal to grade 1 haze developed in the 2 patients (n = 3 eyes) treated for keratoconus. In the CAP group, the UCVA was between 20/40 and 20/80; the B CVA improved in 3 of 4 eyes (75.0%) and declined from 20/20 to 20/25 at 3 m onths in the remaining eye due to haze. The ablation produced some spherica l flattening in both groups, resulting in induced hyperopia that was genera lly clinically insignificant. Conclusion: Early results of this experimental custom-ablation technique ar e promising. J Cataract Refract Surg 2000; 26:1442-1450 (C) 2000 ASCRS and ESCRS.