The Dry Eye Zone

Rebecca's Blog


Study: Is incomplete blink a part of your dry eye picture?

It’s been so frustrating to watch over the years as a poor blink continues to get ignored in a great deal of dry eye diagnosis and treatment. And yet it’s so core to how our tear system performs! The blink mechanism is what pumps and spreads our tears, and our blink is how our eyes stay covered and protected a significant amount of the day. It stands to reason that a poor blink has the potential to be a really big deal for dry eye disease.

I appreciate any and all research efforts that could move us closer to seeing blink evaluation as an integral part of dry eye diagnosis.

Evaluation of incomplete blinking as a measurement of dry eye disease. Jie et al, Ocul Surf 2019 May 29.



To investigate the association between partial blinking during spontaneous blinking as measured by interferometry and ocular exams for the assessment of dry eye disease (DED).


This retrospective study included 58 eyes of patients previously diagnosed with DED. Ocular surface assessment included ocular surface disease index (OSDI) score, tear film osmolarity, tear breakup time (TBUT), grading of corneal fluorescein staining, Schirmer I test, and dry eye parameters by the LipiView™ interferometer (TearScience, Morrisville, NC, USA), including lipid layer thickness of the tear film (LLT), meibomian gland dropout (MGd), number of incomplete and complete blinks per 20 s and the partial blinking rate (PBR). Generalized estimation equations (GEE) were used for association testing between each variable of interest. The working correlation for each GEE model was selected using the Corrected Quasi-likelihood under the Independence Model Criterion.


The number of incomplete blinks was significantly associated with TBUT (P = 0.006), OSDI (P = 0.000) and MGd (P = 0.000). PBR was significantly associated with OSDI (P = 0.032) and MGd (P = 0.000). The number of complete blinks was significantly associated with TBUT (P = 0.032), but not with other ocular surface parameters. MGd was significantly associated with TBUT (P = 0.002) and OSDI (P = 0.001). LLT was significantly associated with tear film osmolarity (P = 0.007), and tear film osmolarity was significantly associated with LLT (P = 0.000).


Incomplete blinking is associated with decreased TBUT, increased OSDI, and increased MGd possibly through its contribution to meibomian gland obstruction and subsequent loss of tear film homeostasis. It may therefore be considered an additive measure for mild-to-moderate DED assessment.