Blink completeness and rate in dry eye disease: An investigator-masked, prospective registry-based, cross-sectional, prognostic study

Purpose: To investigate the prognostic ability of blink rate and the proportion of incomplete blinking to predict dry eye disease diagnosis, as defined by the TFOS DEWS II criteria.

Methods: A total of 453 community residents (282 females, 171 males; mean ± SD age, 37 ± 19 years) were recruited in an investigator-masked, prospective registry-based, cross-sectional, prognostic study. Dry eye symptomology, tear film quality, and ocular surface characteristics were assessed in a single clinical session, and blink parameters evaluated by an independent masked observer.

Results: Overall, 214 (47 %) participants fulfilled the TFOS DEWS II criteria for dry eye disease. Multivariate regression analysis demonstrated that an increased proportion of incomplete blinking was associated with a higher odds of dry eye disease (odds ratio, 1.12 per 10 % increase; 95 % CI, 1.05-1.19; p < 0.001), with the Youden-optimal prognostic threshold proportion being ≥ 40 % incomplete blinking. Higher levels of incomplete blinking were also associated with poorer dry eye symptomology, tear film stability, corneal and lid margin staining, lipid layer thickness, meibography, and meibum quality (all p ≤ 0.03). No significant associations were detected between blink rate and ocular surface parameters (all p > 0.10).

Conclusions: The degree of incomplete blinking is a significant predictor of dry eye disease, and the utility of incorporating blink assessment into diagnostic workup algorithms warrants further investigation. The association with meibomian gland dropout, expressed meibum quality, and lipid layer thickness would suggest that incomplete blinking may predispose towards the development of meibomian gland dysfunction.