Reliability of a New Non-invasive Tear Film Break-up Time Measurement Using a Keratograph

Abstract

Purpose: To evaluate the repeatability of non-invasive tear film break-up time and identify its relationships with dry eye parameters. Methods: A total of 100 participants (50 with dry eye, and 50 in the control group) were enrolled prospectively. Non-invasive kera-tograph first (NIKf-BUT) and average (NIKav-BUT) break-up times were evaluated 2 times using Keratograph 4 (Oculus, Wetzler, Germany), and then tear film break-up time with fluorescein (FBUT) was measured. The correlation analyses were performed between non-invasive parameters (NIKf-BUT and NIKav-BUT) and FBUT. Intra-observer agreements of NIKf-BUT and NIKav-BUT were assessed using intraclass correlation coefficients (ICC). The receiver operating characteristic (ROC) curve technique was used to evaluate the non-invasive method in the diagnosis of dry eye. Results: The correlation analyses revealed positive correlation between NIKav-BUT and FBUT in both groups (dry eye; r = 0.66, p < 0.001 and control group; r = 0.77, p < 0.001). The ICCs of NIKf-BUT and NIKav-BUT were 0.72 and 0.94 in the dry eye, respectively, and 0.70 and 0.91 in the control group. NIKav-BUT was not different from FBUT in either group. The areas under the ROC curves of NIKf-BUT and NIKav-BUT were 0.917 and 0.980, respectively. Conclusions: The high ICCs verified the repeatability of NIKf-BUT and NIKav-BUT. NIKav-BUT showed no difference from FBUT and positive correlation with FBUT. NIK-BUT showed high diagnostic power and can be considered a new parameter to evaluate dry eye syndrome. 안구건조증은 눈물과 안구표면의 다양한 요인에 의해 발 생하는 질환으로 안구불편감과 시각장애, 눈물막 이상을 초 래한다. 1 안구건조증은 일반적으로 환자의 주관적 증상과 눈물생성, 눈물막 안정성, 각결막 손상정도로 평가한다. 2 이 중에서 눈물막 안정성을 평가하는 눈물막파괴시간은 1969 년 처음 소개된 이후 안구건조증 진단에 임상 지표로 널리 이용되었다. 3 플루오레신 염색약을 이용하는 눈물막파괴시간(fluorescein tear film break-up time, FBUT)은 침습적 검사법에 해당한 다. 플루오레신은 눈물막을 염색하여 코발트블루 광원에서 눈물막 결손을 쉽게 찾아낼 수 있게 해주지만, 눈물막 안정