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Human cornea: Superior and central oxygen demands

  • W. J. Benjamin
  • R. M. Hill
Original Investigations

Abstract

Corneal oxygen demands, expressed as ratios of uptake rate relative to baseline rates derived from unstressed corneas, were determined with a micropolarographic system for central (closed eye) and superior (open eye) locations of one cornea of each of seven human subjects. The closed-eye central corneal measurements were repeated during two additional experimental sessions. Intrasubject variability of the three mean closed-eye central corneal rate ratios ranged as high as 23%, possibly representing effects of homeostatic mechanisms on the palpebral conjunctival capillaries of some subjects. For the open-eye superior cornea, which was covered by the upper eyelid of every subject prior to measurement, oxygen demand was found to have a greater intersubject range, but was diminished in magnitude relative to the demand associated with the closed-eye central cornea. Superior corneal oxygen demand was not found to be predictable from closed-eye central corneal oxygen demand or extent of eyelid overlap onto the cornea and thus indicated localized open-eye superior corneal environments that were significantly different from those of the corresponding closed-eye central corneas. Such localized environments may be critically important when gauging the susceptibility of particular eyes to superior corneal pathology during contact lens wear.

Keywords

Uptake Rate Oxygen Demand Rate Ratio Experimental Session Contact Lens 
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References

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Copyright information

© Springer-Verlag, Berlin Heidelberg 1988

Authors and Affiliations

  • W. J. Benjamin
    • 1
  • R. M. Hill
    • 2
  1. 1.Institute for Contact Lens Research, University of Houston, College of OptometryHoustonUSA
  2. 2.Eye Physiology LaboratoryThe Ohio State University, College of OptometryColumbusUSA

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