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The effects of rigid contact lenses overall diameter changes on tear pump efficiency: A comparative study

Fink, Barbara A., Hill, Richard M., & Carney, Leo G. (1991) The effects of rigid contact lenses overall diameter changes on tear pump efficiency: A comparative study. International Contact Lens Clinic, 18, pp. 95-101.

Abstract

A seriesof three studies was performed to evaluate the effects of rigid contact lens overall diameter changes on tear pump efficiency. In all three studies,corneal oxygen-uptake rates were measured on the right eye of six subjects under three conditions:normal open eye, after 5 minutes of static (without blinking) contact lens wear, and after 5 minutes of dynamic (with blinking once every 5 seconds) contact lens wear. Measurements were repeatedeighttimesfor eachlens/corneasystem. In StudyI, five lens diameters were used, varying from 8.2 to 9.4 mm in 0.3mm steps, with optic-zone diameters1.4 mm less and all other parameters constant. In Study Il, seven lens diameters were used, varying from 8.2 to 10.0 mm in 0.3 mm steps, with a constant 7.4 mm optic-zone diameter for all lenses and all other parameters constant. In Study Ill, six lens diameters were used, varying from 7.6 to 10.6 mm in 0.6 mm steps, optic-zone diameters1.4 mm less, base-curve radii varying with optic-zone diameter to maintain a constant apical tear-layer thickness,and all other parameters constant. A reduction in corneal oxygen demand with decreasing lens overall diameter was seen under dynamic conditions in all three studies.Greatest and most consistent tear pump efficiencies, as reflected by large differences between static and dynamic measurements, were also found with the smallest lenses in all three studies.

Impact and interest:

2 citations in Scopus
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ID Code: 3152
Item Type: Journal Article
Additional Information: For more information, please refer to the journal's website (see link) or contact the author. Author contact details: l.carney@qut.edu.au
Additional URLs:
Keywords: Contact Lenses, cornea, diameter, tear exchange, oxygen
ISSN: 0892-8967
Subjects: Australian and New Zealand Standard Research Classification > MEDICAL AND HEALTH SCIENCES (110000) > OPTOMETRY AND OPHTHALMOLOGY (111300)
Divisions: Current > QUT Faculties and Divisions > Faculty of Health
Current > Institutes > Institute of Health and Biomedical Innovation
Copyright Owner: Copyright 1991 Elsevier
Deposited On: 30 Jan 2006
Last Modified: 15 Jan 2009 16:54

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