Objectives
Measurement of tear film stability is central in dry eye disease (DED) diagnosis. In this study, we aimed to compare the performance of two methods of tear film stability measurement: non-invasive tear break-up time (NIBUT) and fluorescein tear film break-up time (FTBUT).
Design
Cross-sectional study.
Setting and participants
The study involved 132 subjects of 65-year-old inhabitants of the Oslo region who were not seeking ophthalmic care.
Interventions
The participants underwent a battery of DED tests, including NIBUT measured on Oculus Keratograph 5M and a traditional method using fluorescein drops (FTBUT). Oculus Keratograph 5M measures two types of NIBUT:; appearance time of the first dry spot (NIBUTFirst) and average NIBUTAvg.
Results
74 participants (56%) were female and 58 were male (44%). Subjects presented with varying degrees of DED signs and symptoms. Mean values of NIBUTFirst and FTBUT from all the participants were significantly different (6.2±4.9 s vs 8.6±6.2 s, p