Intersubject variability in corneal swelling response to anoxia.

A controlled, double-masked, randomized experiment was conducted on 9 human subjects, to determine whether there is an intersubject difference in the corneal swelling response to anoxia. A statistically significant intersubject variability was observed (P less than 0.001), with oedema ranging from a mean of 3.6% to 7.3% following 3 h exposure to humidified nitrogen gas (anoxia). This result supports the hypothesis of previous workers that the intersubject difference in the corneal oedema response to a thick HEMA "stress lens" is due to oxygen deprivation and not some other physiological variable resulting from lens wear.