Control of Induced Spherical Aberration in Moderate Hyperopic LASIK by Customizing Corneal Asphericity

Abstract

Purpose: To compare differences in induced aberrations and visual acuity after wavefront-optimized LASIK and aspheric-customized LASIK for the treatment of hyperopia.

Methods: Forty consecutive eyes underwent uneventful LASIK for treatment of moderate hyperopia (+3.82 ± 0.63 diopters [D] [+2.75; +5.125]). A standard procedure was performed in the wavefront-optimized LASIK group (n = 24), whereas a postoperative Q-factor equal to zero was scheduled in the aspheric-customized LASIK group (n = 16).

Results: At 6 months, mean spherical aberration for a 6-mm pupil diameter was -0.39 ± 0.23 µm (range: -0.76 to 0.01 µm) and Q-factor was -0.52 ± 0.22 (range: -1.00 to -0.12 µm) in the wavefront-optimized group and 0.04 ± 0.18 µm (range: -0.34 to 0.29 µm) and -0.04 ± 0.25 (range: -0.64 to 0.40 µm) in the aspheric-customized LASIK group (P ≤ .05). All remaining outcomes showed no significant differences between groups. UDVA was 20/18.69 ± 0.15 (range: 0.80 to 1.20) in the wavefront-optimized LASIK group and 20/20 ± 0.17 (range: 0.50 to 1.20) in the aspheric-customized LASIK group. One patient in the wavefront-optimized LASIK group lost two or more lines of CDVA and no lines were lost in the aspheric-customized LASIK group.

Conclusions: The results in this small cases series suggest that using an aspheric-customized ablation profile with a target Q-factor equal to 0 in moderate hyperopic LASIK is statistically compatible with a diminishing induced spherical aberration without altering procedural safety when the WaveLight Allegretto 400-Hz excimer laser platform (Alcon Laboratories, Inc., Fort Worth, TX) is used.