Purchase this article with an account.
Mengxi Niu, Norihiko Yokoi, Hiroaki Kato, Rieko Sakai, Aoi Komuro, Yukiko Sonomura, Noriko Koizumi, Shigeru Kinoshita; The comparison of 3 different methods used for the evaluation of precorneal tear film breakup time. Invest. Ophthalmol. Vis. Sci. 2014;55(13):1982.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Evaluation of tear film stability is important for the diagnosis of dry eye, and there are several methods by which to perform the evaluation. The purpose of this present study was to evaluate the breakup time (BUT) of the precorneal tear film via 3 different methods and to investigate the relationship between those methods.
This study involved 100 eyes of 100 dry-eye patients (15 males and 85 females, mean age: 63.2 years) treated at the dry eye clinic of Kyoto Prefectural University of Medicine, Kyoto, Japan. In all eyes, non-invasive breakup time (NIBUT, seconds) was measured once by use of a video-interferometer (DR-1™; Kowa, Tokyo, Japan), followed by NIBUT being measured once by use of video topography (TNIBUT, seconds), and finally, fluorescein BUT (FBUT, seconds) was measured 3 times and the values were averaged. The BUT values from the 3 methods described above were then compared and their correlation was analyzed.
BUT values for FBUT, NIBUT, and TNIBUT were 2.3±1.9, 3.3±2.9, and 4.4±3.4, respectively, and significant difference was found between FBUT and NIBUT, FBUT and TNIBUT, and NIBUT and TNIBUT (p<0.05). Spearman’s correlation coefficient values (all p<0.0001) between each examination were 0.738 (FBUT-NIBUT), 0.647 (FBUT-TNIBUT), and 0.733 (NIBUT-TNIBUT), indicating that the coefficient value was smallest in the FBUT-TNIBUT comparison than in the other comparisons.
The results of this present study show that FBUT, NIBUT, and TNIBUT are all methods that can be used to evaluate tear film breakup. However, since only NIBUT reflects the real full-thickness breakup of tear film, due to the fact that only video-interferometry can directly observe the actual process of tear-film breakup, it can be said that FBUT merely reflects the aqueous tear film thinning prior to the full-thickness breakup of the tear film, as fluorescein is dissolved in the aqueous layer and aqueous layer thinning occurs prior to the full thickness (lipid layer and aqueous layer) breakup of tear film. On the other hand, considering that the TNIBUT resulted in the longest BUT value and that the correlation coefficient between NIBUT and TNIBUT was larger than that in FBUT-TNIBUT, it can be said that TNIBUT also reflects full thickness breakup, although the sensitivity of TNIBUT is less than that of NIBUT.
This PDF is available to Subscribers Only