Comparison of non-invasive tear film stability measurement techniques

• Published in: Clinical and experimental optometry Vol. 101; no. 1; pp. 13 - 17
• Main Authors: Wang, Michael Tm, Murphy, Paul J, Blades, Kenneth J, Craig, Jennifer P
• Format: Journal Article
• Language: English
• Published: Melbourne Taylor & Francis 01.01.2018; Wiley Publishing Asia Pty Ltd; Taylor & Francis Ltd
• Subjects: Adult; break-up time; Cornea - metabolism; Cross-Over Studies; Female; Humans; Interferometry - methods; Male; Measurement techniques; non-invasive techniques; Prospective Studies; Reference Values; Single-Blind Method; tear film; tear film stability; Tears - chemistry; tear film; break-up time; tear film stability; non-invasive techniques
• ISSN: 0816-4622; 1444-0938; 1444-0938
• DOI: 10.1111/cxo.12546

Measurement of tear film stability is commonly used to give an indication of tear film quality but a number of non-invasive techniques exists within the clinical setting. This study sought to compare three non-invasive tear film stability measurement techniques: instrument-mounted wide-field white light clinical interferometry, instrument-mounted keratoscopy and hand-held keratoscopy. Twenty-two subjects were recruited in a prospective, randomised, masked, cross-over study. Tear film break-up or thinning time was measured non-invasively by independent experienced examiners, with each of the three devices, in a randomised order, within an hour. Significant correlation was observed between instrument-mounted interferometric and keratoscopic measurements (p < 0.001) but not between the hand-held device and the instrument-mounted techniques (all p > 0.05). Tear film stability values obtained from the hand-held device were significantly shorter and demonstrated narrower spread than the other two instruments (all p < 0.05), while no significant differences were observed between the two instrument-mounted devices (all p > 0.05). Good clinical agreement exists between the instrument-mounted interferometric and keratoscopic measurements but not between the hand-held device and either of the instrument-mounted techniques. The results highlight the importance of specifying the instrument employed to record non-invasive tear film stability.