Corneal hypoxia and hypercapnia during contact lens wear
Restriction of both oxygen influx to the cornea and carbon dioxide efflux from the cornea by contact lenses results in adverse tissue changes. We measured the extent of hypoxia and hypercapnia at the corneal surface of 10 human volunteers during static, dynamic (blinking), and closed-eye wear of hydrogel and nonhydrogel contact lenses of different gas transmissibilities. During open-eye wear, hypoxia and hypercapnia are lower beneath lenses of higher oxygen and carbon dioxide transmissibilities, respectively (p less than 0.001). Blinking plays a significant role in alleviating corneal hypoxia (p less than 0.05), but not hypercapnia, during lens wear. In the absence of lenses, the gaseous tensions at the anterior corneal surface during eye closure were: pO2 = 37.4 +/- 20.9 mm Hg and pCO2 = 39.3 +/- 3.1 mm Hg. Closed-eye lens wear resulted in greater levels of hypoxia and hypercapnia that were directly correlated with lens transmissibility (p less than 0.001). These data form the basis of models for predicting adverse tissue changes during contact lens wear and suggest prophylactic and therapeutic clinical strategies for alleviating lens-induced hypoxia and hypercapnia.
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|Item Type:||Journal Article|
|Additional Information:||Self-archiving of the author-version is not yet supported by this publisher. For more information, please refer to the journal's website (see hypertext link) or contact the author. email@example.com|
|Keywords:||Contact Lenses, /adverse effects, Oxygen Consumption, Cornea/, metabolism, Adult, Analysis of Variance, Anoxia/etiology, Blinking, Carbon Dioxide/metabolism, Female, Humans, Hypercapnia/etiology, Male, Partial Pressure, Research Support, Non, U, S, Gov't|
|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 1990 Lippincott, Williams and Wilkins|
|Deposited On:||17 Feb 2006|
|Last Modified:||15 Jan 2009 16:56|
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