Purpose: To investigate changes of corneal thickness at the vertical and horizontal meridians and of wavefront aberrations (WA) over a 30-day period of overnight myopia orthokeratology (OK) lens wear.
Methods: Sixteen subjects (11 women, 5 men, 26.3±3.2 years) were enrolled and fitted for OK lenses. Long scan depth optical coherence tomography was used to measure corneal thickness profiles at both horizontal and vertical meridians at baseline and on days 1, 7, and 30 days. Corneal and ocular WA of a 6-mm pupil were measured and the root-mean-square (RMS) of the astigmatism, coma, spherical aberration (SA), and total higher-order aberrations (HOAs) were determined.
Results: During the 30-day period, the central cornea thinned in the horizontal and vertical meridians, whereas corneal thickening occurred in the temporal, nasal, and inferior mid-peripheries. In contrast, the cornea thinned in the mid-peripheral superior. There were significant increases in RMS for astigmatism, SA, coma, and positive horizontal coma during the study period. After OK, there were significant positive correlations between the midperipheral-central thickness change difference and the changes in corneal and ocular RMS of total HOAs and SA (r range: 0.281 to 0.492, P<0.05). Only the change of corneal coma RMS was correlated with midperipheral-central thickness change difference (r=0.270, P<0.05). The change in corneal horizontal coma was correlated with the temporal-nasal thickness change difference (r=−0.289, P<0.05).
Conclusions: Overnight OK caused unique changes in corneal thickness profiles at the vertical and horizontal meridians and increased corneal and ocular HOAs related to corneal reshaping.
School of Ophthalmology and Optometry (Y.L., M.S., S.H., Y.Y., Y.W., D.Z., J.J., X.M., and F.L.), Wenzhou Medical University, Wenzhou, Zhejiang, China; and Department of Ophthalmology (J.W.), Bascom Palmer Eye Institute, University of Miami, Miami, FL.
Address correspondence to Fan Lu, M.D., O.D., School of Ophthalmology and Optometry, Wenzhou Medical University, 270 Xueyuan Road, Wenzhou, Zhejiang 325027, China; e-mail: email@example.com
Y. Lian and M. Shen contributed equally to the study.
Supported by Zhejiang Provincial Natural Science Foundation of China (Y13H180030 to M.S.), Zhejiang Medical Technology & Education of China (2013KYA132 to M.S.), National Natural Science Foundation of China (81170869 to F.L., 81101081 to D.Z.), and Zhejiang Provincial College Students Science and Technology Innovation Activity Plan Foundation of China (2012R413036 to Y.L.).
The research review board of Wenzhou Medical University approved this study.
Accepted February 04, 2014