Abstract
Purpose :
Although meibomian gland structure and function can be assessed through meibography and measurement of lipid layer thickness (LLT), the role of blink parameters on the tear film has not yet been fully elucidated. Blink frequency and completeness may impact the lipid layer thickness measurement. In this retrospective cohort study, the relationship between LLT, meiboscore, blink rate, partial blink rate, and inter-blink interval were investigated.
Methods :
This is a single-center, retrospective cohort study at the Loyola University Medical Center. We analyzed 2 years of data (2018-2020) generated from the LipiView Interferometer device for 456 eyes. The meiboscore of each eye was graded using the (4 point) Heiko Pult meiboscore. Inter-blink interval was determined from the Lipiview report using the measuring tool application on Adobe Acrobat DC. Linear mixed-effects models were used to analyze the relationship between LLT, meiboscore, blink rate, partial blink rate, and inter-blink interval.
Results :
For every 1-point increase in the Pult meiboscore, the average LLT declined by -1.31 units (95% CI: -3.57 to 0.95; p = .26) and the total blink rate decreased by 4% (RR = 0.96; 95% CI: 0.91 – 1.03; p = .26). Both measures were not statistically significant. LLT and inter-blink interval did not differ significantly between disease states (floppy eyelid syndrome, obstructive sleep apnea, meibomian gland dysfunction, ocular graft vs host disease, Stevens-Johnson Syndrome). There was no statistically significant difference in LLT in patients with a partial blink rate >50% as compared to a partial blink rate <50%. However, there was an association between inter-blink interval (in seconds) and partial blink rate (%). That is, a partial blink rate between >0% to 50% had an inter-blink interval that was -0.73 (95% CI: -1.33 to -0.13) seconds shorter on average than with a 0% partial blink rate (p = .01).
Conclusions :
A decrease in LLT is associated with increased meibomian gland dropout (meiboscore). Patients who blink more completely (have an incomplete blink rate less than 50% of the time) have a shorter inter-blink interval (time between blinks). We speculate that in patients with an increase in partial blinks, the longer inter-blink interval results from impaired corneal sensation related to the chronic exposure.
This is a 2021 ARVO Annual Meeting abstract.