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First Author: J.Liang TAIWAN
Co Author(s): J. Chen Y. Chen
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The aim of this study was to investigate the effect of orthokeratology on optical performance of the eye by measuring wavefront aberrations after overnight fitting with programmed reverse geometric hard contact lenses.
Department of Ophthalmology, Tri-service General hospital, Taipei, Taiwan
Ten patients received overnight orthokeratology for at least 6 months. Hartman-Shack aerometer (Visx) was used to assess wavefront aberrations, and Zernike aberrations were calculated. The Orbscan Slit Scan Corneal Topography System Analyzer (Orbtek, Salt Lake City, UT) was used to check the corneal topography.
When the contact lens is well centered, the central flattening - just as the laser refractive procedure - induced spherical aberration. If the contact lens has lateral or vertical displacement, it will induce horizontal or vertical coma just as with decentration of laser ablation. The spherical aberration and coma are the main high-order aberrations for patients following orthokeratology. The measure of optical quality with modulation transfer function shows the retinal image quality get worse after orthokeratology as compared to only high-order aberrations.
The wavefront change after orthokeratology is similar to laser refractive surgery. Spherical aberration and coma are the most frequent high-order aberrations