Abstract
Purpose:
The tracking of spontaneous blink activity has been shown to permit an investigator to gather important information on the clinical state of a dry eye subject. Previous research has shown that the majority of blinks are incomplete with zero lid contact duration time. During a complete blink, lid duration contact time may vary from less than 10ms to 80ms. Eyelid closures of up to multiple seconds, which we refer to as "extended blinks", may also be observed. Here we investigate the relative incidence of incomplete and extended blinks in a dry eye population.
Methods:
We consider a sample population of 11 non-MGD dry eye subjects and a control group of 10 normal subjects. Blink information was obtained using video analysis of each subject viewing a 10 minute nature documentary. Incomplete blinks were tracked by percent of palpebral fissure closure as ¼, ½ and 3/4. Extended blinks of multiple seconds were classified per the cutpoints(sec) = (0, 0.1, 1).
Results:
Total number of blinks observed for all subjects was 4990 (1414 normal, 3756 dry eye). Of total blinks, 50.6% were incomplete (dry eye) versus 52% (normal). Dry eye subjects were over 10 times more likely than normals to exhibit blinks of one second duration or longer (2.3% vs 0.2% of total respective blinks, p=0.023). Mean lid closure duration for dry eye subjects was 7.074 (p<.001), 4.274 (p=0.003) and 4.490 (p<.001) times greater than for normals for all blinks of duration greater than 0 sec, 0.1 sec and 1 sec respectively.
Conclusions:
The results suggest that blink duration may play an important role as a biomarker for dry eye. The relative ease of tracking blink behavior promises improved tracking of the effects of treatment and success in clinical trial outcomes.
Keywords: 486 cornea: tears/tear film/dry eye •
479 cornea: clinical science