Abstract
Purpose :
The rate of blinks provides important insights into the severity of dry eye disease. Without blinking the tear film over the ocular surface will break up and visual acuity will decay, so understanding blink rate is critical to determining the source of ocular discomfort from dry eye. Here we evaluated blink rate at different gaze positions to help determine what gaze prevents blinks or increases blink rates.
Methods :
Videos of 4 subjects were acquired from one eye at 3 different gaze positions: up, straight ahead, and down, with 3 one-minute recordings at each gaze position. Patients were instructed to look up approximately 10 degrees from the front position and down approximately 15 degrees from the front position. Videos were recorded using the Ora EyeCup phone with the flash on in 4k and then blinks were counted from each video.
Results :
When averaging the whole group across all views the mean blink rate was 15 (standard deviation (stdev) 7.9) blinks per minute. Upward and front facing gaze both led to a similar number of blinks 16 (stdev 6.1) blinks per minute and 16.25 (stdev 8.2) blinks per minute respectively, while a downward gaze subjects averaged 12.2 blinks per minute. A downward gaze showed only trending significance compared to the front gaze (p=0.069) and upward gaze (p=0.1).
Conclusions :
Gaze is a critical factor in blink rate with a downward gaze leading to a lower average number of blinks. This result is in line with the fact that as our gaze lowers so does the interpalpebral fissure height, leading to less exposure of the ocular surface.
This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.