Repeatability of non-invasive break-up time measures with a new automated dry eye platform in healthy eyes

Abstract

Purpose: To evaluate the intrasession repeatability for non-invasive break-up time (NIBUT) and tear meniscus height (TMH) measurements provided by a new multi-diagnostic platform, and to assess the interobserver reproducibility of TMH measures.

Methods: Twenty-one healthy eyes of 21 patients (ages 23–65 years) were enrolled. A complete eye examination was performed in all cases with Visionix’s VX 120+ dry eye device, including an analysis with the new Dry Eye module, performing three consecutive measurements. The within-subject standard deviation (Sw) and Bland– Altman plots were used to assess intrasession repeatability. Differences between examiners for TMH were also analyzed.

Results: No statistically significant differences were found between repeated measures of NIBUT (time associated with the first break) and TMH (p 0.05). However, significant differences were found for NIBUT50% (time associated with half of breaks of the tear film) (p ≤0.05). Mean Sw was 0.9 s, 1.4 s and 0.05 mm for NIBUT, NIBUT50% and TMH, respectively. Ranges of agreement between consecutive measures were below 3.5 s and 4.5 s for NIBUT and NIBUT50%, respectively, and below 0.16 mm for TMH. Furthermore, no significant differences were found between examiners in TMH measure, with an inter-examiner range of agreement of 0.12 mm.

Conclusions: The new dry eye platform of the VX 120+ Dry Eye platform evaluated provides objective automated measures of NIBUT and TMH, with acceptable level of intrasession repeatability for clinical screening purposes.

Keywords: Dry eye, VX 120+, VX 120+ Dry Eye, Non-invasive tear film break-up time NIBUT, Tear meniscus height.