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Lee, Park, Park, Lee, Choi, Jung, and Lee: Effect of Toric Orthokeratology Lenses on Patients with More Than 1.5 Diopter of Corneal Astigmatism
Original Article

J Korean Ophthalmol Soc 2015;56(6):830-834.

Published online: 7 September 2015

DOI: https://doi.org/10.3341/jkos.2015.56.6.830

Effect of Toric Orthokeratology Lenses on Patients with More Than 1.5 Diopter of Corneal Astigmatism

Jong Heon Lee, MD1, Young Min Park, MD1, Young Kee Park, MD, PhD2, Jong Su Lee, MD, PhD1, Hee Young Choi, MD, PhD1, Jae Ho Jung, MD, PhD1, 3, Ji Eun Lee, MD, PhD1, 3

1Department of Ophthalmology, Pusan National University School of Medicine, Busan, Korea

2YK Eye Clinic, Seoul, Korea

3Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, Korea

Address reprint requests to Ji Eun Lee, MD, PhD Department of Ophthalmology, Pusan National University Yangsan Hospital, #20 Geumo-ro, Mulgeum-eup, Yangsan 626-770, Korea, Tel: 82-55-360-2590, Fax: 82-55-360-2161 E-mail: jiel75@hanmail.net

Received 14 November 201427 December 2014       Accepted 23 April 2015

Copyright © 2015 Korean Ophthalmological Society

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose

To report the effect of toric orthokeratology lenses on myopic patients who have more than 1.5 diopter (D) of corneal astigmatism.

Methods

Seventeen patients (24 eyes) who wore toric orthokeratology lenses for more than 6 months were recruited for this study. The uncorrected visual acuity (UCVA), refractive error and keratometric changes including eccentricity before and after wearing lenses were compared. The correlations between corneal astigmatism as well as refractive astigmatism and lens toricity and between corneal astigmatism and improvement of UCVA after lens fitting were assessed.

Results

After wearing lenses, UCVA (log MAR) was significantly improved from 0.93 ± 0.13 to 0.09 ± 0.07 (p < 0.001). Myopia changed from -4.53 ± 1.55 D to -0.67 ± 0.80 D (p < 0.001), refractive astigmatism from -1.48 ± 0.71 D to -0.99 ± 0.72 (p = 0.008) and spherical equivalent from -5.27 ± 1.56 D to -1.12 ± 0.92 D (p < 0.001). Simulated K (Sim K) tended to be more flat (p < 0.001) and the eccentricity was significantly decreased from 0.45 ± 0.08 to -0.69 ± 0.45 (p < 0.001), but corneal astigmatism was not significantly changed from 2.05 ± 0.41 D to 2.01 ± 0.98 D (p = 0.803). Correlation between corneal astigmatism and lens toricity was statistically significant (r = 0.526, p = 0.012) but not between refractive astigmatism and lens toricity (r = 0.218, p = 0.329). The amount of corneal astigmatism was not correlated with the improvement of uncorrected visual acuity after lens fitting (r = 0.1804, p = 0.399).

Conclusions

Toric orthokeratology lenses might be an effective treatment in patients with corneal astigmatism who cannot be fit-ted with spherical orthokeratology lenses. Lens toricity was correlated with corneal astigmatism and the amount of corneal astigmatism did not affect the improvement of uncorrected visual acuity after lens fitting.

Keywords: Corneal astigmatism, Myopia, Toric orthokeratology

References

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Figure 1.
Comparison of refractive changes between before and after wearing toric orthokeratology lens. Only corneal astigmatism was not changed significantly after wearing lens.
jkos-56-830f1.tif
Figure 2.
Correlation between corneal astigmatism before lens wearing and improvement of uncorrected visual acuity (UCVA) after lens wearing. Improvement of UCVA was not correlated with pre-fitting corneal astigmatism (r = 0.1804, p = 0.399).
jkos-56-830f2.tif
Table 1.
Demographics of patients
  Patients
Eyes (number) 24
OD/OS (eyes) 11/13
Male/female (number) 7/10
Age (year) (range) 15 (6-40)
Follow up period (months) (range) 8 (6-17)

OD = oculus dexter; OS = oculus sinister.

Table 2.
Comparison of uncorrected visual acuity, refractive error, and keratometric value
  Before wearing lens After wearing lens p-value
Uncorrected visual acuity (log MAR) 0.93 ± 0.13 (0.70-1.0) 0.09 ± 0.07 (0-0.22) <0.001
Myopia (D) -4.53 ± 1.55 (-8.00~-2.00) -0.67 ± 0.80 (-2.0~0.5) <0.001
Refractive astigmatism (D) -1.48 ± 0.71 (-3.0~-0.25) -0.99 ± 0.72 (-2.75~0) 0.008
Spherical equivalent (D) -5.27 ± 1.56 (-8.63~-2.75) -1.12 ± 0.92 (-2.88~0.25) <0.001
Sim K max (D) 44.99 ± 2.05 (40.13- 49.20) 42.30 ± 2.32 (38.14- 46.17) <0.001
Sim K min (D) 42.94 ± 1.93 (38.62- 47.14) 40.29 ± 1.89 (37.25- 44.35) <0.001
Corneal astigmatism (D) 2.05 ± 0.41 (1.52-3.06) 2.01 ± 0.98 (0.30-4.35) 0.803
Eccentricity 0.45 ± 0.08 (0.26-0.55) -0.69 ± 0.45 (-1.28~0.50) <0.001

Values are presented as mean ± SD (range) unless otherwise indicated.

Sim K = simulated K.

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