A novel, dynamic, in vivo, non-contact method of measuring oxygen depletion rate of the anterior eye

Abstract

Despite the importance of oxygen measurements, techniques have been limited by their invasive nature and small corneal area of assessment. The aim of this study was to assess a non-contact way of measuring oxygen uptake of the whole anterior eye. The device consisted of a goggle with an oxygen sensitive material on the inner surface. As the output is affected by temperature, a second probe was inserted into the goggle to compensate. The goggle was positioned over the eye on 10 subjects (mean age 30.5±5.0 years, 3:2 male:female) to assess the oxygen depletion of the unrestricted, blinking eye. Measurements were taken over a 3 min period. The volume contained within the goggle and bone structure of individual eyes was measured by water volume displacement and the output corrected to O(2)% reduction/cm(3) over a 30s period. To check the discriminatory ability of the device, measurements were taken in open-eye and closed-eye conditions, along with on the subjects' skin (cheek) for comparisons. The oxygen depletion measure over 30s was on average 3.10±1.51 O(2)%cm(3) during open eye condition, significantly more than during closed eye conditions (1.26±1.52 O(2)%cm(3)). The skin (control) showed a negligible oxygen uptake (0.19±0.33 O(2)%cm(3)). The results demonstrated good repeatability with a mean standard deviation of around 0.4 O(2)%cm(3) (equating to 11%). The technique demonstrated a non-invasive, non-contact method of measuring consumption of oxygen within the goggle (oxygen depletion rate) and showed good within-visit repeatability.