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Ophthalmic Physiologic Optic - 2025 - Iqbal - Quantifying tear exchange during rigid contact lens wear using corneoscleral2.80 MB
Published VersionCC BY-NC-ND V4.0, Open Access
Journal article
Quantifying tear exchange during rigid contact lens wear using corneoscleral profilometry: A proof of concept study
Ophthalmic and Physiological Optics, Vol.45(3), pp.598-606
2025
PMID: 39825685
Abstract
Introduction
Tear exchange during contact lens wear is essential for ocular surface integrity, facilitating debris removal, and maintaining corneal metabolism. Fluorophotometry and fluorogram methods are typically used to measure tear exchange, which require hardware modifications to a slit lamp biomicroscope. This manuscript introduces an alternative method using a corneoscleral profilometer, the Eye Surface Profiler (ESP), to quantify tear exchange during corneal and scleral rigid lens wear by assessing fluorescence intensity changes over time.
Methods
As a proof of concept, a healthy participant wore a corneal and a scleral rigid lens on separate days. After lens application, 2% sodium fluorescein was instilled, and ESP images were captured at intervals over a 30-min period for corneal and a 90-min period for the scleral lens. Fluorescence intensity data were extracted and analysed using MATLAB, restricted to a region of interest centred on the contact lens. The fluorescence intensity was fitted with an exponential decay curve to quantify tear exchange.
Results
Fluorescence intensity decreased over time for both lenses, with a faster decay rate being observed for the corneal lens. The scleral lens showed an initial ingress of fluorescein into the fluid reservoir, then a slow decay in fluorescence intensity due to limited tear exchange. The decay rate for the corneal lens was approximately four times faster than the scleral lens, with the time to reach 50% decay of ~42 min for the corneal lens compared to ~157 min for the scleral lens.
Conclusion
A new method was developed to quantify tear exchange using a commercially available corneoscleral profilometer, offering a wider field of view than existing techniques. This approach has clinical potential in scleral lens practice for identifying landing zone misalignment and improving the understanding of post-lens tear dynamics, particularly in cases involving scleral lens modifications or patients experiencing midday fogging.
Details
- Title
- Quantifying tear exchange during rigid contact lens wear using corneoscleral profilometry: A proof of concept study
- Authors
- Asif Iqbal (Corresponding Author) - Queensland University of TechnologyDamien Fisher - Queensland University of TechnologyDavid Alonso-Caneiro - University of the Sunshine Coast, Queensland, School of Science, Technology and EngineeringMichael J Collins - Queensland University of TechnologyStephen J Vincent - Queensland University of Technology
- Publication details
- Ophthalmic and Physiological Optics, Vol.45(3), pp.598-606
- Publisher
- Wiley-Blackwell Publishing Ltd.
- Date published
- 2025
- DOI
- 10.1111/opo.13450
- ISSN
- 1475-1313; 0275-5408
- PMID
- 39825685
- Copyright note
- © 2025 The Author(s). Ophthalmic and Physiological Optics published by John Wiley & Sons Ltd on behalf of College of Optometrists. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.
- Grant note
- Asif Iqbal was funded by a QUT Postgraduate Research Award PhD scholarship and a Dorothy Carlborg Research Award from the Cornea and Contact Lens Society of Australia.
- Organisation Unit
- School of Science, Technology and Engineering
- Language
- English
- Record Identifier
- 991096126602621
- Output Type
- Journal article
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