Optical ray tracing-guided laser in situ keratomileusis for moderate to high myopic astigmatism

To assess the efficacy, safety, and predictability of an individualized laser in situ keratomileusis (LASIK) ablation profile based on an optical ray-tracing algorithm to treat moderate to high myopic astigmatism.

Ophthalmology centers in Zurich, Switzerland; Dublin, Ireland; and, Cologne, Germany.

Multicenter clinical trail.

This 3-center study enrolled eyes with a manifest refraction sphere ranging from 0.50 to -10.25 diopters (D) and/or astigmatism ranging from 0.00 to -4.50 D. The intended outcome was plano in most eyes, undercorrection of 0.50 D in 1 eye, and undercorrection of 0.25 D in 2 eyes. Refractive outcomes were analyzed preoperatively and postoperatively at 1 day and 1 and 3 months.

The study enrolled 127 eyes (71 patients). The mean manifest refraction was -5.92 D ± 1.72 (SD). By 3 months postoperatively, 15 eyes had been lost to follow-up and 1 eye was excluded from analysis because of early retreatment. Of the remaining 111 eyes, 93 (83.8%) had an uncorrected distance visual acuity (UDVA) of 20/20 or better. The mean manifest refraction spherical equivalent (MRSE) in all eyes was 0.03 ± 0.30 D. In 97 (87.4%), the MRSE was within ±0.50 D and in 107 (96.4%), within ±1.00 D. No eye lost 2 or more lines of corrected distance visual acuity.

The new optical ray-tracing algorithm for individualized LASIK ablation profiles to treat moderate to high myopic astigmatism was efficacious, safe, and predictable. The UDVA in eyes with high myopic astigmatism was better than in those treated with wavefront-guided LASIK.