Higher‐Order Wavefront Aberrations in Corneal Refractive Therapy

Purpose. To assess the changes in higher‐order (third through sixth) ocular wavefront aberrations produced by Corneal Refractive Therapy (CRT; Paragon Vision Sciences, Mesa, AZ). Methods. Eighteen eyes of nine myopic subjects were fit with CRT contact lenses. Baseline subjective spherical refraction ranged from −2.25 to −6.00 D (mean ± SD, −3.33 ± 1.26 D), and baseline logarithm of the minimum angle of resolution (logMAR) best‐corrected visual acuity was −0.13 ± 0.06 (20/15 Snellen equivalent). Whole‐eye ocular wavefront aberrations were measured using a previously validated Shack‐Hartmann aberrometer. Measurements were taken at baseline and 1 month after treatment initiation. Nine measurements per dilated subject were taken and averaged. Zernike coefficients were used to calculate the third‐, fourth‐, fifth‐, and sixth‐order root‐mean‐square values for each eye for both 3‐ and 6‐mm pupil sizes, and aberrations were averaged and compared with prior baseline readings. Results. The mean (±SD) myopia reduction was 3.08 ± 0.93 D, resulting in a subjective refraction of −0.22 ± 0.38 D after 1 month of lens wear. Both logMAR uncorrected visual acuity (−0.07 ± 0.18; 20/15 − Snellen equivalent) and best‐corrected visual acuity (−0.14 ± 0.09) after CRT wear were not significantly different from baseline logMAR best‐corrected visual acuity (paired two‐tailed t‐test; p = 0.41 and 0.65, respectively). Whole‐eye aberrations showed a statistically significant increase in higher‐order aberrations for both 3‐mm (factor of 2.66; p = 0.01) and 6‐mm pupils (factor of 2.50; p = 0.005). Each individual higher‐order aberration also increased, ranging from a factor of 2.01 to 3.20 for 3‐mm pupil sizes and 2.52 to 2.98 for 6‐mm pupil sizes. Spherical‐like aberrations (S4 and S6) increased by a factor of 1.79 for 3‐mm pupil sizes and 2.42 for 6‐mm pupil sizes. The Zernike coefficient most affected by CRT was spherical aberration (Z 4 0 ), which increased from 0.084 ± 0.16 to 0.39 ± 0.16 μm (p = 0.0002) for 6‐mm pupils. Conclusions. Use of current CRT lenses for the reduction of myopia increased higher‐order wavefront aberrations and spherical aberration (Z 4 0 ) in particular.