title: Corneal reshaping and wavefront aberrations during overnight orthokeratology.
abstract: OBJECTIVE
  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.
authors.affiliation: 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.
authors.forename: Yan
authors.initials: Y
authors.lastname: Lian
authors.forename: Meixiao
authors.initials: M
authors.lastname: Shen
authors.forename: Shenghai
authors.initials: S
authors.lastname: Huang
authors.forename: Yimin
authors.initials: Y
authors.lastname: Yuan
authors.forename: Yaozeng
authors.initials: Y
authors.lastname: Wang
authors.forename: Dexi
authors.initials: D
authors.lastname: Zhu
authors.forename: Jun
authors.initials: J
authors.lastname: Jiang
authors.forename: Xinjie
authors.initials: X
authors.lastname: Mao
authors.forename: Jianhua
authors.initials: J
authors.lastname: Wang
authors.forename: Fan
authors.initials: F
authors.lastname: Lu
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D057108:Corneal Wavefront Aberration / Q000473:pathology / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D009216:Myopia / Q000473:pathology / Q000628:therapy*; D054158:Orthokeratologic Procedures; D041623:Tomography, Optical Coherence; D055815:Young Adult