Abstract
Purpose :
The TearViewTM infrared emissivity camera is designed to dynamically visualize lipids and proteins on the ocular surface in real time. This technology detects light that is naturally emitted. Emissivity is dependent on the composition, structure, temperature, and thickness of materials with lipids appearing lighter and proteins appearing darker. The dynamic distribution of the tear film was compared in participants with dry eye disease (PDED) and without DED (Pn).
Methods :
Over 5,000 IR emissivity video images were captured from 10 PDED and 13 Pn at 1, 2, 3, 4 and 5s after blinking using a TearView™ camera (Beyond 700, Castle Hill, New South Wales, Australia). Grey-scale pixel intensity (Ie) and heterogeneity (H) in the canthus and lower, middle, and upper ocular surface regions were measured.
Results :
For PDED compared with Pn, Ie at 0s blink time was 24, 30 (P=0.006) and 11% higher, and the decrease after blinking was 44, 102 (P=0.04) and 39% steeper in the upper, middle and lower regions, respectively. This suggests that the tear film of PDED has altered lipid distribution and/or quantity and/or is at a higher temperature and thins at a higher rate in all regions compared with Pn. For Pn, the H of the lower and upper regions were 42 to 45% lower compared with the middle region (P=0.038), suggesting the middle region had a more heterogeneous surface. For PDED, the H of the lower and upper regions were only 15 to 17% lower than the H of the middle regions (P=0.026) suggesting the heterogeneity of the regions were more consistent with DED compared with Pn. The H for PDED was 24% lower(P=0.026) compared with Pn. The canthus region Ie was 38 % lower (darker) in PDED compared with Pn (P< 0.001). The darkness could be attributed to aggregated proteins.
Conclusions :
IR emissivity measurements indicate altered tear film dynamics/composition in PDED including increased tear film thinning between blinks and altered lipid/protein distribution. An IR emissivity camera may be a useful tool to evaluate alterations in the regional dynamic distribution of tear film components in patients with ocular surface disease and by age, sex, race and treatment.
This abstract was presented at the 2024 ARVO Imaging in the Eye Conference, held in Seattle, WA, May 4, 2024.