Time course of changes in ocular higher-order aberrations and contrast sensitivity after overnight orthokeratology
Takahiro Hiraoka 1*,
Chikako Okamoto 2,
Yuko Ishii 2,
Tetsuhiko Kakita 3,
Fumiki Okamoto 2,
and
Tetsuro Oshika 2
1 Department of Ophthalmology, University of Tsukuba, 1-1-1Tennoudai, Tsukuba, 305-8575, Japan
2 Department of Ophthalmology, University of Tsukuba, Tsukuba, Ibaraki, Japan
3 Kakita Eye Clinic, Nagareyama, Japan
* To whom correspondence should be addressed. E-mail: thiraoka{at}md.tsukuba.ac.jp.
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Abstract |
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Purpose: To prospectively investigate the time course of changes in ocular higher-order aberration and contrast sensitivity after overnight orthokeratology.
Methods: Data from 34 eyes of 17 patients who completed 1-year follow-up examinations were analyzed. The manifest refraction was -2.17 ± 0.86 diopters at baseline. Ocular higher-order aberrations for a 4-mm pupil were measured, and the root-mean-square (RMS) of the third-, and fourth-, and total higher-order aberrations were determined. Contrast sensitivity was assessed at four spatial frequencies, and the area under the log contrast sensitivity function (AULCSF) was calculated. These examinations were performed before and 1,2,3,6, and 12 months after commencement of the procedure.
Results: The treatment significantly increased third-order, fourth-order, and total higher-order RMS (all P < 0.0001, paired t-test). Log contrast sensitivity significantly decreased at all four spatial frequencies, and AULCSF was also significantly reduced after the treatment (P < 0.0001). To assess the time course of changes in these parameters, post-treatment data were analyzed using repeated-measures analysis of variance. There were no significant fluctuations in manifest refraction, uncorrected visual acuity, third-order RMS, fourth-order RMS, total higher-order RMS, and AULCSF (all P > 0.05). In addition, there was no significant variance in log contrast sensitivity at each spatial frequency during the 1-year follow-up period (all P > 0.05).
Conclusions: The initially reduction in optical quality of the eye and quality of vision after the procedure is stable during the treatment period of at least 1 year, and the reduction does not further worsen after one month. Orthokeratology candidates should be fully informed of these changes.
Key Words:
contrast sensitivity, optics, contact lenses, overnight orthokeratology, higher-order aberrations, quality of vision
