Lateral shearing interferometry for analysis of tear film surface kinetics.
OBJECTIVE
To date, there have been no measuring techniques available that could clearly identify all phases of tear film surface kinetics in one interblink interval.


METHODS
Using a series of cases, we show that lateral shearing interferometry equipped with a set of robust parameter estimation techniques is able to characterize up to five different phases of tear film surface kinetics that include: (i) initial fast tear film build-up phase, (ii) further slower tear film build-up phase, (iii) tear film stability, (iv) tear film thinning, and (v), after a detected break-up, subsequent tear film deterioration.


RESULTS
Several representative examples are given for estimating tear film surface kinetics in measurements in which the subjects were asked to blink and keep their eyes open as long as they could.


CONCLUSIONS
Lateral shearing interferometry is a noninvasive technique that provides means for temporal characterization of tear film surface kinetics and the opportunity for the analysis of the two-step tear film build-up process.
Szczesna
Dorota H
DH
Faculty of Fundamental Problems of Technology, School of Optometry, Queensland University of Technology, Brisbane, Queensland, Australia.
Iskander
D Robert
DR
D000328:Adult; D000368:Aged; D005260:Female; D006801:Humans; D007368:Interferometry / Q000379:methods*; D007700:Kinetics; D008297:Male; D013666:Tears / Q000378:metabolism*; D013997:Time Factors; D055815:Young Adult