April 2010
Volume 51, Issue 13
Free
ARVO Annual Meeting Abstract  |   April 2010
Underestimation of Intraocular Pressure After Orthokeratology
Author Affiliations & Notes
  • R. Yanai
    Ocular Pathophysiology, Yamaguchi University School of Medicine, Ube, Japan
  • Y. Ishida
    Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Japan
  • T. Sagara
    Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Japan
  • K. Suzuki
    Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Japan
  • T.-I. Chikama
    Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Japan
  • T. Nishida
    Ophthalmology, Yamaguchi University Graduate School of Medicine, Ube, Japan
  • H. Toshida
    Ophthalmology, Juntendo University School of Medicine, Bunkyo, Japan
  • A. Murakami
    Ophthalmology, Juntendo University School of Medicine, Bunkyo, Japan
  • Footnotes
    Commercial Relationships  R. Yanai, None; Y. Ishida, None; T. Sagara, None; K. Suzuki, None; T.-I. Chikama, None; T. Nishida, None; H. Toshida, None; A. Murakami, None.
  • Footnotes
    Support  None.
Investigative Ophthalmology & Visual Science April 2010, Vol.51, 1533. doi:
  • Views
  • Share
  • Tools
    • Alerts
      ×
      This feature is available to authenticated users only.
      Sign In or Create an Account ×
    • Get Citation

      R. Yanai, Y. Ishida, T. Sagara, K. Suzuki, T.-I. Chikama, T. Nishida, H. Toshida, A. Murakami; Underestimation of Intraocular Pressure After Orthokeratology. Invest. Ophthalmol. Vis. Sci. 2010;51(13):1533.

      Download citation file:


      © ARVO (1962-2015); The Authors (2016-present)

      ×
  • Supplements
Abstract

Purpose: : Orthokeratology is a method for correction of mild myopia. It reduces corneal power by flattening corneal curvature and reducing central corneal thickness (CCT). Measurement of intraocular pressure (IOP) with a noncontact tonometer (NCT), which determines the time taken for a jet of air to induce corneal applanation, is dependent on CCT and the radius of corneal curvature. To investigate the possible effect of orthokeratology on IOP measurement with an NCT, we compared IOP values determined before and after this procedure. We also examined the relation between any change in IOP readings and changes in CCT or the radius of corneal curvature.

Methods: : The study design was a prospective, interventional case series, and informed consent was obtained from each subject. Both eyes of 29 subjects were fitted with overnight reverse-geometry orthokeratology lenses, which were then worn for >4 h overnight. Subjects were free of ocular disease and had a corrected visual acuity of ≥ 1.0. Uncorrected visual acuity, refraction, IOP, and CCT were measured and keratometry was performed.

Results: : Before orthokeratology, uncorrected visual acuity, spherical equivalent value, IOP, mean radius of corneal curvature, and CCT were 0.16 (0.9 logMAR), -2.7 ± 1.00 (mean ± SD) D, 14.1 ± 2.7 mmHg, 7.91 ± 0.26 mm, and 540.2 ± 38.1 µm, respectively. After orthokeratology, the corresponding values were 1.06 (-0.01 logMAR), -0.27 ± 0.85 D, 12.3 ± 2.9 mmHg, 8.13 ± 0.30 mm, and 532.9 ± 43.1 µm. The changes in all parameters were statistically significant (P < 0.05). The change in IOP was significantly correlated with that in corneal curvature but not with that in CCT or spherical equivalent value.

Conclusions: : Orthokeratology for myopia reduces NCT readings of IOP by flattening corneal curvature. Orthokeratology may thus result in underestimation of IOP.

Keywords: contact lens • intraocular pressure • cornea: clinical science 
×
×

This PDF is available to Subscribers Only

Sign in or purchase a subscription to access this content. ×

You must be signed into an individual account to use this feature.

×