Takahiro Hiraoka1, Tetsuhiko Kakita2, Fumiki Okamoto3, Tetsuro Oshika3. 1. Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan. Electronic address: thiraoka@md.tsukuba.ac.jp. 2. Kakita Eye Clinic, Chiba, Japan. 3. Department of Ophthalmology, Faculty of Medicine, University of Tsukuba, Ibaraki, Japan.
Abstract
PURPOSE: To determine ocular optical parameters that affect axial length elongation in myopic children undergoing overnight orthokeratology. DESIGN: Prospective, noncomparative study. PARTICIPANTS: Fifty-nine subjects who met the inclusion criteria were enrolled in this study. METHODS: Axial length and ocular wavefront aberration were assessed before and 1 year after the start of orthokeratology. Corneal topography was performed, and then corneal multifocality was calculated for a 4-mm pupil. After evaluating simple correlations between axial elongation and optical parameters, multiple linear regression analysis was performed to identify explanatory variables with a statistically significant contribution to axial elongation. MAIN OUTCOME MEASURES: Axial length and ocular wavefront aberration before and 1 year after the start of orthokeratology. RESULTS: Fifty-five subjects completed the 1-year follow-up examinations. At baseline, their age ranged from 7.2 to 12.0 years. The manifest spherical equivalent refractive error ranged from -3.50 to -0.75 diopters. The mean axial length significantly increased from 24.20 mm at baseline to 24.43 mm 1 year after treatment. The axial elongation showed significant simple correlations with the change in C2(0), change in second-order aberration, change in coma-like aberration, change in spherical-like aberration, change in total higher-order aberrations, change in corneal multifocality, baseline age, and baseline spherical equivalent refractive error, but not C4(0). Multiple linear regression analysis showed that the change in coma-like aberration was the most relevant variable. CONCLUSIONS: Asymmetric corneal shapes, rather than concentric and radially symmetric shapes, have a considerable effect on retardation of axial elongation, suggesting that the inhibitory effect of orthokeratology on myopia progression is caused by mechanisms other than the reduction in peripheral hyperopic defocus.
PURPOSE: To determine ocular optical parameters that affect axial length elongation in myopic children undergoing overnight orthokeratology. DESIGN: Prospective, noncomparative study. PARTICIPANTS: Fifty-nine subjects who met the inclusion criteria were enrolled in this study. METHODS: Axial length and ocular wavefront aberration were assessed before and 1 year after the start of orthokeratology. Corneal topography was performed, and then corneal multifocality was calculated for a 4-mm pupil. After evaluating simple correlations between axial elongation and optical parameters, multiple linear regression analysis was performed to identify explanatory variables with a statistically significant contribution to axial elongation. MAIN OUTCOME MEASURES: Axial length and ocular wavefront aberration before and 1 year after the start of orthokeratology. RESULTS: Fifty-five subjects completed the 1-year follow-up examinations. At baseline, their age ranged from 7.2 to 12.0 years. The manifest spherical equivalent refractive error ranged from -3.50 to -0.75 diopters. The mean axial length significantly increased from 24.20 mm at baseline to 24.43 mm 1 year after treatment. The axial elongation showed significant simple correlations with the change in C2(0), change in second-order aberration, change in coma-like aberration, change in spherical-like aberration, change in total higher-order aberrations, change in corneal multifocality, baseline age, and baseline spherical equivalent refractive error, but not C4(0). Multiple linear regression analysis showed that the change in coma-like aberration was the most relevant variable. CONCLUSIONS: Asymmetric corneal shapes, rather than concentric and radially symmetric shapes, have a considerable effect on retardation of axial elongation, suggesting that the inhibitory effect of orthokeratology on myopia progression is caused by mechanisms other than the reduction in peripheral hyperopic defocus.
Authors: Meng-Jun Zhu; Li Ding; Lin-Lin Du; Jun Chen; Xian-Gui He; Shan-Shan Li; Hai-Dong Zou Journal: Int J Ophthalmol Date: 2022-08-18 Impact factor: 1.645