Ocular Surface Displacement with and without Contact Lenses during Non-Contact Tonometry

Ulfah Rimayanti,Joji Takenaka,Makoto Kaneko,Shohei Uemura,Hideki Mochizuki,Yoshiaki Kiuchi,Rajiv R Mohan

doi:10.1371/journal.pone.0096066

Ulfah Rimayanti, Joji Takenaka + Show 5 more

Open Access

https://doi.org/10.1371/journal.pone.0096066

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Journal: PloS one	Publication Date: Apr 29, 2014
Citations: 26	License type: CC BY 4.0

Affiliation: Hiroshima University, Osaka University

Abstract

PurposeTo evaluate the displacement of the central ocular surface during non-contact tonometry with and without soft contact lenses and determine the factors associated with the displacement of the central ocular surface and intraocular pressure (IOP) reading changes caused by wearing soft contact lenses (CLs).MethodsOne eye each in 21 subjects was studied. The cornea was photographed using a high-speed camera at 5,000 frames/sec during non-contact tonometry without contact lenses (NCL), with -5.0 diopters (D), -0.5 D and +5.0 D CL. The displacement of the ocular surface and the factors affecting displacement at the IOP reading and maximum displacement time were investigated.ResultsThe IOP readings while wearing +5 D CL were significantly higher than those obtained while wearing -5 D CL. The ocular surface displacement between +5 D CL and other groups were significantly different. A significant positive correlation was found between the ocular surface displacement of subjects at the IOP reading time and the IOP obtained with the non-contact tonometer. A significant negative correlation was found between the ocular surface curvature and the IOP obtained using the non-contact tonometer. The radius of curvature of the ocular surface affected the displacement during the IOP reading and maximum displacement time.ConclusionsOur results indicate that soft contact lens use changes the ocular surface behavior and IOP readings during non-contact tonometry. The radius of curvature of the eye affects the ocular surface displacement and IOP readings in this situation.

Highlights

Obtaining accurate measurements of the intraocular pressure (IOP) is an important part of ocular examinations
Other studies have found that the IOP measured on non-contact tonometry through soft contact lenses is altered and that the changes depend on the lens power, curvature, thickness and rigidity [10,11,12,13,14,15]
Our findings indicate that the radius of curvature of the anterior surface of the eye is associated with the amount of ocular surface displacement and IOP readings obtained with the non-contact tonometer

Summary

Introduction

Obtaining accurate measurements of the intraocular pressure (IOP) is an important part of ocular examinations. Non-contact tonometry employs an applanation method using a standardized air puff to flatten the cornea [3]. As the pressure of the air puff increases to deform the cornea, the corneal surface behaves like a mirror and reflects light to the detector on the tonometer. Monitoring the IOP is an essential part of daily clinic activity, and tonometry through the soft contact lenses is convenient especially when treating subjects with ocular surface diseases. Other studies have found that the IOP measured on non-contact tonometry through soft contact lenses is altered and that the changes depend on the lens power, curvature, thickness and rigidity [10,11,12,13,14,15]. Most reports have examined the correlations between IOP readings and lens factors, and there is no agreement as to why IOP readings change after wearing soft contact lenses

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Conclusion