Objective: To evaluate the accuracy of diagnosing dry eye disease (DED) by using the
Visionix VX120+, to establish reference values for tear meniscus height (TMH) and non-invasive
break-up time (NIBUT), and to compare the NIBUT measurements with the fluorescein tear break-up
time (FBUT), Methods: fifty-eight subjects (34 dry eye and 24 control) were enrolled. The TMH, first
NIBUT, and NIBUT50% were evaluated with the Visionix VX120+, and the FBUT was measured with
a slit-lamp. The Receiver Operating Characteristic (ROC) curve was used to evaluate the diagnostic
performance, and the Bland–Altman method was performed to analyze the agreement. Results: The
areas under the curve were 0.62, 0.60, and 0.70 for the TMH, first NIBUT, and NIBUT50%, respectively.
The optimal cut-off values (sensitivity, specificity) were 0.29 (0.62, 0.67), 5.05 (0.85, 0.46), and 7.35
(0.65, 0.79) for the TMH, first NIBUT, and NIBUT50%, respectively. The mean differences (lower,
upper limits of agreement) were −1.10 (−8.78, 6.58) and 1.55 (−5.68, 8.78) for the first NIBUT vs.
FBUT and the NIBUT50% vs. FBUT, respectively. Conclusions: In conclusion, the NIBUT50% can
be a useful tool for dry eye screening, with acceptable values of sensitivity and specificity. First, the
NIBUT and NIBUT50% should not be used interchangeably with the FBUT.
