Blink patterns and lid-contact times in dry-eye and normal subjects

Abstract

PurposeTo classify blinks in dry eye and normal subjects into six subtypes, and to define the blink rate and duration within each type of blink, as well as the total lid-contact time/minute.Materials and methodsThis was a single-centered, prospective, double-blind study of eleven dry-eye and ten normal subjects. Predefined subjects watched a video while blinks were recorded for 10 minutes. Partial blinks were classified by percentage closure of maximal palpebral fissure opening: 25%, 50%, 75%. Complete blinks were characterized as full (>0 seconds), extended (>0.1 seconds), or superextended (>0.5 seconds). The mean duration of each type of blink was determined and standardized per minute as total lid-contact time.ResultsTotal blinks observed were 4,990 (1,414 normal, 3,756 dry eye): 1,809 (50.59%) partial and 1,767 (49.41%) complete blinks among dry-eye subjects versus 741 (52.90%) partial and 673 (47.60%) complete blinks among normal subjects. Only superextended blinks of ≥0.5-second duration were significantly more frequent in dry-eye subjects than normals (2.3% versus 0.2%, respectively; P=0.023). Total contact time was seven times higher in dry-eye subjects than normals (0.565 versus 0.080 seconds, respectively; P<0.001). Isolating only extended blinks (>0.1 second), the average contact time (seconds) was four times longer in dry-eye versus normal subjects (2.459 in dry eye, 0.575 in normals; P=0.003). Isolating only superextended blinks (>0.5 seconds), average contact time was also significantly different (7.134 in dry eye, 1.589 in normals; P<0.001). The contact rate for all full closures was 6.4 times longer in dry-eye (0.045 versus 0.007, P<0.001) than normal subjects.ConclusionDry-eye subjects spent 4.5% of a minute with their eyes closed, while normal subjects spent 0.7% of a minute with their eyes closed. Contact time might play a role in the visual function decay associated with increased blink rates.

Association between dry eye symptoms and signs

“…Dry eye patients spend more time with their eyes closed than normal patients. 20 Blink rate was significantly related to the OSDI scores of the subjects. The correlation coefficient meant that as the blink rate scores increased the OSDI scores of the participants also decreased.…”

Risk factors for severe Meibomian gland atrophy in a young adult population: A cross-sectional study

“…One explanation may be that eyes which have a thick tear lipid layer may have less of an urge to blink completely, and those with a thinner tear lipid layer are more inclined to blink completely in order to increase or restore tear lipid layer thickness. Ousler, et al reported that there were slightly more partial blinks (52.9%) among normal eyes than among dry eyes (50.96%) and that total contact time (lid-to-lid) was seven times longer in dry-eye subjects than normal subjects (0.565 versus 0.080 seconds, respectively; P<0.001)[ 42 ]. While poor tear film can be the result of partial blinking tendencies in those individuals [ 43 – 46 ], we might consider that another group of individuals exist who are less inclined to blink completely due to the presence of a robust tear film.…”

Spontaneous Eye Blink Patterns in Dry Eye: Clinical Correlations

“…Previous studies mostly focused on the spontaneous blink rate and the incomplete blink rate, but more complex patterns of blinks appeared in DED patients and each phase of the blink procedure might be important to understand the relationship between DED and blinking. The study from Ousler et al 18 indicated that extended lid closures and increased blink rates were the main differences between DED and healthy subjects. Rahman et al 19 found that rapid blinking was associated with worse ocular surface and tear film instability.…”