Correlation among Myopic Correction, Axial Length and Aberration after Orthokeratology Lens Treatment in Myopic Patients

ABSTRACT

PURPOSE: To report the correlation among the amount of myopic correction, axial length elongation, and higher order aberrations after treatment with orthokeratology lenses in myopic patients. METHODS: Eighteen patients (36 eyes) treated with orthokeratology lenses for more than 12 months were recruited for this study. Visual acuity, spherical equivalent, axial length, and higher order aberrations were measured at baseline and 1, 6, and 12 months after wearing lenses. Correlations among them were analyzed. RESULTS: Total higher order, spherical, vertical and horizontal coma aberrations were significantly increased from 0.85 ± 1.47, −0.22 ± 0.40, 0.40 ± 0.47, 0.22 ± 0.31 to 1.11 ± 0.72, 0.10 ± 0.38, 0.79 ± 0.63, 0.66 ± 1.29 after 1 month repectively (p 0.05), remaining up to 12 months.Total and corneal spherical aberrations were positively correlated to the amount of myopic correction (p = 0.001 and p = 0.028, repectively) and negatively to the amount of axial length elongation (p = 0.036 and p = 0.079, repectively). Uncorrected visual acuity and spherical equivalent were significantly improved from 0.52 ± 0.08 and −2.41 ± 0.36 to 0.07 ± 0.07 and −0.84 ± 0.32 after 1 month respectively. This improvement was maintained up to 12 months (p = 0.002 and p = 0.001, respectively). Axial length was continuously increased from 24.31 ± 0.53 mm to 24.91 ± 0.60 mm after 12 months, but showed no significant changes (p = 0.721). CONCLUSIONS: Although orthokeratology lenses were effective for the correction of myopia, they increased higher order aberrations depending on the amount of myopic correction. Physicians should consider higher order aberrations. Further studies regarding the relationship between axial length elongation and higher order aberrations to retard myopic progression should be conducted.