Abstract
Purpose :
To define and characterize the optical behavior of the anterior surface of the human eye during visual fixation.
Methods :
Twenty healthy participants were included, 60% female, aged from 25 to 42 years (33.05 ± 4.97 [mean ± SD]). To perform high-resolution imaging, subjects were instructed to fixate on a central target in the OCT device, and meanwhile scanning session was executed at different time-points after blinking. After one hour, OCT imaging was repeated to verify the reliability of results. During each measuring session, a pulse oximetry was used for continuously measuring the heart rate and oxygen saturation (SpO2%). Overall, a total of 200 OCT scans were performed.
Results :
An interference pattern of the tear film with an oscillatory appearance was detected at the 2nd, 3rd, 4th, 5th, and 6th second after blinking, respectively, in 18%, 24%, 18%, 24%, and 16% of scans during the first session. A significant correlation was found between interference pattern and heart rate during the first and the second session (p<0.01). Reproducibility analysis demonstrated a statistically significant intraclass correlation (ICC) value for OCT imaging of anterior surface of the eyes (ICC = 0.838; p<0.01), indicating the high level of reliability of the results.
Conclusions :
There exists an interference pattern of the anterior surface of the human eye during visual fixation detectable by en-face OCT, which is mainly evident as heart rate increases. Its recognition could have considerable impact on the understanding of physiology of vision and various ocular diseases, as well as on the relationship between the vascular system (heart rate), the nervous system (fixation movements) and the lacrimal system.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.