Abstract
Purpose:
This study evaluates the repeatability and reproducibility of tear film evaporation rate measurement using a commercially available handheld closed-chamber evaporimeter (VapoMeter, Delfin Technologies, Finland).
Study Design:
This was a randomized observational study, in which two visits were required. At visit 1, screening tests were performed on the participants. Subsequently, tear evaporation was measured thrice by examiner 1 (E1). The procedure was then repeated by examiner 2 (E2) at visit 2.
Methods:
40 healthy participants with no ocular diseases were recruited for this study. A closed chamber evaporimeter was used in this study (VapoMeter, Delfin Technologies, Finland). Primary investigations, including slit-lamp examination, tear production test, and ocular discomfort, were performed during the first visit for the purpose of screening.
Results:
The mean of the three measurements of tear evaporation obtained by examiner 1 at visit 1 was 19.38 +/- 0.79 g/m(2)/h, and the mean of the three readings obtained by examiner 2 at visit 2 was 20.49 +/- 0.48 g/m(2)/h. The average Intraclass Correlation Coefficient (ICC) among the three readings of tear evaporation was 0.84 and 0.63 with a 95% confidence interval ( CI) at visits 1 and 2, respectively. A comparison of the reliability of the measurements from the two examiners revealed an ICC of 0.69 with a 95% CI.
Conclusion:
The VapoMeter provides repeatable and reproducible measurements of tear film evaporation. This study demonstrates that the VapoMeter could provide clinicians with a readily available method for rapid evaluation of tear film evaporation. By considering the significance of tear evaporation as a diagnostic tool for dry eyes, the VapoMeter may help to diagnose better and manage dry eye syndrome.