Abstract
Purpose:
To develop a continuous blink tracking device and investigate diurnal blink as a clinical endpoint.
Methods:
Blink data were collected using a wearable telemetric device to record electromyograms corresponding to activity of the orbicularis oculi muscle. Subjects with no history of ocular disease were tested for verification and validation of the diurnal blink device. Verification testing was performed to ensure that the device accurately recorded blink rate compared to manually recorded blink activity from video capture (N=7). Validation testing of the device was performed to examine the variability of hourly and daily repeated measurements (N=9). Finally, the effect of exposure to a 90 minute controlled adverse environment (CAESM) challenge and an exaggerated 30 minute CAESM challenge on blink rate (N=6) was examined.
Results:
In the verification study, the mean blink rate was 10.79 blink/minute (standard deviation, SD 3.48) with the device versus 10.61 (SD 4.01) with manual counting. In the validation study, mean daily blink rates and IBIs, calculated to test for daily variability, were not significantly different from day 1 to day 2 (p=0.164 and p=0.060, respectively). On the first day, the mean blink rate was 14.22/minute (SD 6.28), IBI was 4.73 seconds (SD 1.41), and on the second day, mean blink rate was 11.61/minute (SD 3.28), IBI was 5.61 (SD 1.76). IBIs during the 90-minute CAESM challenge were not significantly different compared to mean hourly IBIs before or after challenge (p>0.19). However, during the exaggerated CAESM challenge, mean IBIs (3.35, SD 0.871) were significantly decreased compared to pre-CAESM values (4.54, SD 0.955)(p=0.026).
Conclusions:
These preliminary data support the verification and validation of the diurnal blink tracking device. Additionally, the device has demonstrated its ability to successfully measure changes in blink patterns due to alternations in environmental conditions. These studies demonstrate that continuous blink tracking utilizing this method has potential applications in future dry eye studies.
Keywords: 526 eyelid •
486 cornea: tears/tear film/dry eye •
468 clinical research methodology