Abstract
Purpose: :
Blink rate has long been studied in conjunction with dry eye and it has been shown that non-dry eye subjects blink significantly less than subjects diagnosed with dry eye while watching TV, using a computer and reading[1]. The current study evaluated not blink rate alone, but blink patterns, meaning the occurrence of blink types, (extended, full, partial), varying interblink intervals, and the completeness of blinks over time. This study was conducted to better characterize the presentation of blink patterns in normal and dry eye subjects.[1] P Walker, R White K Lane, MB Abelson. A Comparative Assessment of Blink Rates across a Series of Tasks in Dry Eye and Control Patients. ARVO 2007 5317/D759..
Methods: :
A total of 20 subjects participated (n=10 diagnosed with dry eye, n=10 normal). Blink patterns were collected over a ten minute period while the subject performed a controlled visual task (television watching) and were compared between populations.
Results: :
Dry eye subjects and non dry eye subjects had average IBIs of 2.61 and 5.57 seconds, respectively (p=0.002). Maximum IBI was significantly different for the two groups, 14.34 and 25.19 seconds respectively (p=0.034). Variance of IBI also differed significantly between the groups and was shown to be higher in normals than dry eye (0.28 difference in standard deviation between populations, p=.004)) The two populations were significantly different in incidence of extended full blinks, occurring 1% and 4% of the time in dry eye and non dry eye subjects, respectively (p=0.031).
Conclusions: :
We have shown that these two patient populations are clearly differentiated in blink pattern and have confirmed increased frequency of blinks in dry eye subjects as well as the inability of dry eye subjects to sustain extended IBIs. This differentiation between the two groups may provide a better understanding of the role of blink patterns in dry eye and their potential modulation in therapeutic trials.
Keywords: anterior segment • cornea: clinical science • cornea: tears/tear film/dry eye