Corneal oxygen uptake associated with piggyback contact lens systems.
OBJECTIVE
The purpose of this study was to determine the effects of static (without blinking) and dynamic (with blinking once every 5 seconds) wear of piggyback contact lens systems on corneal oxygen uptake.


METHODS
Corneal oxygen uptake rates were measured on the right eyes of 11 human subjects by using a polarographic electrode. Measurements were made for the normal open eye and after 5 minutes of wear of 4 rigid lens materials (Dk/t 0-82.5), 4 soft lens materials (Dk/t 13-122), and 16 combinations of rigid and soft lens materials. The piggyback systems were worn under both static and dynamic conditions. Repeated-measures analysis of variance was used to compare oxygen uptake rates associated with the wear of the rigid lens components, soft lens components, piggyback systems, and static versus dynamic wearing conditions. Spearman correlation coefficients and regression analyses were used to examine relationships between corneal oxygen uptake rates.


RESULTS
Measurable differences were found among oxygen uptake rates associated with the rigid lens components, soft lens components, and piggyback systems. Blinking resulted in no reduction in corneal oxygen uptake with the piggyback systems. Corneal oxygen uptake associated with the wear of the piggyback systems could not be predicted from those associated with the rigid and soft lens components of the systems.


CONCLUSIONS
Piggyback combinations of rigid and soft lens components with the highest transmissibilities resulted in the least increase in corneal oxygen uptake beyond that of the normal open eye.
Florkey
Lindsay N
LN
The Ohio State University College of Optometry, 320 West Tenth Avenue, Columbus, OH 43210-1280, USA.
Fink
Barbara A
BA
Mitchell
G Lynn
GL
Hill
Richard M
RM
D000328:Adult; D001767:Blinking / Q000502:physiology; D003261:Contact Lenses; D003263:Contact Lenses, Hydrophilic; D003315:Cornea / Q000378:metabolism*; D005260:Female; D006801:Humans; D008297:Male; D010100:Oxygen / Q000378:metabolism*; D010101:Oxygen Consumption / Q000502:physiology*; D011048:Polarography
D010100:Oxygen