Abstract
Purpose :
To compare fluorescein tear film break up time (FBUT) and non-invasive BUT (NIBUT) measured with KOWA® DR-1 video interferometer and the Oculus® Keratograph 5M.
Methods :
The study involved 50 subjects (6 men and 44 women; mean age ± SD, 37.4 ± 8.1years) who complained of dry eye symptoms. NIBUT were measured with DR-1 (NIBUT-DR) and Keratograph 5M (NIKBUT-1 and NIKBUT-average). Tear meniscus height (TMH) was examined with Keratograph 5M. Measurement of FBUT was performed after NIBUT measurement. To reduce variation of FBUT, strict attention was paid. The fluorescein strip was shaken vigorously and its central top was touched gently to the center of lower lid margin. FBUT was checked three times, and the average of FBUT was used for analysis. The correlations between FBUT and non-invasive tear parameters (NIBUT-DR, NIKBUT-1, NIKBUT-average, and TMH) were calculated using the Spearman’s correlation test. The agreement of FBUT and NIBUT parameters were described by the Bland-Altmann analysis.
Results :
Non-invasive tear parameters significantly correlated with FIBUT (NIBUT-DR: r=0.55, P<0.001; NIKBUT-1: r=0.40, P<0.01; NIKBUT-average: r=0.38, P<0.01; TMH: r=0.30, P<0.05). The Bland-Altmann analysis showed that bias and the 95% limits of agreement between FBUT and NIBUT parameters were as follows: (NIBUT-DR: 2.07 sec, -5.33 to 9.46 sec; NIKBUT-1: 3.39 sec, -5.46 to 12.24 sec; NIKBUT-average: 6.61 sec, -1.58 to 14.79 sec) . There was proportional bias between FBUT and NIBUT.
Conclusions :
Since NIBUT measured with both DR-1 and Keratograph 5M correlated with FIBUT, NIBUT measurement could be useful to understand tear stability. The length of tear break up time was as follow: FBUT<NIBUT-DR<NIKBUT-1<NIKBUT<average. FUBUT was shorter than NIBUT, and could be most sensitive method to detect tear film instability.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.