What question did this study set out to answer?

This study aims to evaluate the impacts of overnight orthokeratology on visual, refractive, and corneal parameters.

April 1, 2026

Overnight Orthokeratology

Key Points

This study aims to evaluate the impacts of overnight orthokeratology on visual, refractive, and corneal parameters.
Ten myopic subjects underwent a 60-day trial of overnight orthokeratology using rigid contact lenses.
Participants were examined at multiple time points: days 1, 7, 14, 30, and 60.
Various assessments included visual acuity (logMAR), subjective refraction, autorefraction, autokeratometry, and corneal topography.
Significant improvement in both high and low-contrast visual acuity by day 7.
At day 60, mean change in high-contrast visual acuity was −0.55 logMAR and low-contrast was −0.48 logMAR.
Subjective refraction and autorefraction significantly reduced by day 60.
Significant central corneal flattening observed with an increase in apical radius and decrease in shape factor.
Central cornea thinning measured at −12 μm by day 60.

Abstract

ABSTRACT: Purpose Orthokeratology is defined as the temporary reduction in myopia by the programmed application of rigid gas‐permeable contact lenses. New reverse geometry contact lens designs and materials have led to a renewed interest in this field. The purpose of this study is to assess visual, refractive, topographic, and corneal thickness changes in subjects undergoing overnight orthokeratology. Methods Ten myopic subjects (mean age, 25.9 ± 3.9 years) were recruited for a 60‐day trial of overnight orthokeratology using reverse geometry rigid contact lenses. After commencing lens wear, subjects were examined on days 1, 7, 14, 30, and 60 at several times throughout the day. High‐ and low‐contrast logarithm of the minimum angle of resolution (logMAR) visual acuity, monocular subjective refraction, autorefraction, autokeratometry, corneal topography, corneal thickness, and slit lamp examinations were performed at each session. Results Eight subjects completed the study. Both high‐ and low‐contrast uncorrected visual acuity improved significantly by day 7. The mean change in uncorrected high contrast visual acuity at day 60 was −0.55 ± 0.20 logMAR (mean at day 60, −0.03 ± 0.16; Snellen equivalent, 20/19). The mean change in uncorrected low‐contrast visual acuity at day 60 was −0.48 ± 0.26 logMAR (mean at day 60, +0.22 ± 0.23; Snellen equivalent, 20/33). The mean subjective refraction and autorefraction were significantly reduced from baseline at day 60 (mean change in subjective refraction, +1.83 ± 1.23 D; mean change in autorefraction, +0.64 ± 0.52 D). Corneal topography showed significant central flattening (mean change in apical radius, +0.20 ± 0.9 mm; mean change in shape factor, −0.11 ± 0.18 at day 60). The central cornea also showed significant thinning (mean change, −12 ± 11 μm at day 60). All visual, refractive, and topographic outcomes were sustained over the course of an 8‐h day. Conclusions Overnight orthokeratology is an effective means of temporarily reducing myopia. The possible mechanism of corneal remodeling through central corneal thinning is discussed.

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Overnight Orthokeratology

Key Points

Abstract

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