Human Tear Enzyme Changes As Indicators of the Corneal Response to Anterior Hypoxia

Fullard, Roderick J. & Carney, Leo G. (1985) Human Tear Enzyme Changes As Indicators of the Corneal Response to Anterior Hypoxia. Acta Ophthalmologica Scandinavica, 63(6), pp. 678-683.


A non-invasive biochemical technique for quantifying the effects of anterior corneal hypoxia on the in vivo corneal epithelium of the human eye is described. Following short-term exposure of the cornea to low atmospheric oxygen pressures, lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) activities in tears are altered so that the tear LDH/MDH ratio is elevated. The degree of elevation of the ratio and its timing are related to the severity of hypoxia. Possible explanations for the elevation of the tear LDH/MDH ratio include unbinding of intracellular LDH and increased cell membrane permeability. For severe hypoxia, de novo LDH synthesis may also contribute. These changes suggest that control mechanisms within the corneal epithelium may be responding to optimize the efficiency of anaerobic metabolism during conditions of environmental stress, and offer the prospect of a non-invasive technique for monitoring epithelial metabolic stress.

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6 citations in Scopus
5 citations in Web of Science®
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ID Code: 3094
Item Type: Journal Article
Refereed: Yes
Additional Information: For more information, please refer to the journal’s website (see link) or contact the author. Author contact details:
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Keywords: Anoxia/, metabolism, Cornea/, metabolism, L, Lactate Dehydrogenase/, metabolism, Malate Dehydrogenase/, metabolism, Tears/, enzymology, Circadian Rhythm, Epithelium/metabolism, Humans, Oxygen Consumption
ISSN: 1395-3907
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 1985 Blackwell Publishing
Copyright Statement: The definitive version is available at
Deposited On: 19 Jan 2006 00:00
Last Modified: 15 Jan 2009 06:54

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