각막지형도를 이용한 새로운 비침습적눈물막파괴시간 검사의 신뢰도 평가

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

목적: 비침습눈물막파괴시간 검사의 재현성을 평가하고 기존 안구건조증 지표와의 관계를 분석해 보고자 하였다. 대상과 방법: 안구건조증군 50명과 정상대조군 50명을 전향적으로 모집하였다. Keratograph 4 (Oculus, Wetzler, Germany)를 이용하여 눈물막 첫 파괴시간(non-invasive keratograph first break-up time, NIKf-BUT)과 평균 파괴시간(non-invasive keratograph average break-up time, NIKav-BUT)을 2회 반복 측정 후, 플루오레신 눈물막파괴시간(tear film break-up time with fluorescein, FBUT)을 측정하고 지표 간 상관관계를 분석하였다. NIKf-BUT와 NIKav-BUT의 급내상관계수와 곡선아래면적을 이용한 진단력을 평가하였다. 결과: NIKav-BUT는 두 군 모두 FBUT와 양의 상관관계를 보였다(dry eye; r=0.66, p<0.001 and control group; r=0.77, p<0.001). NIKf-BUT와 NIKav-BUT의 급내상관계수는 안구건조증군에서 각 0.72와 0.94였고, 대조군에서는 각 0.70과 0.91이었다. NIKav-BUT와 FBUT는 유의한 차이가 없었다. 곡선아래면적은 NIKf-BUT에서 0.917, NIKav-BUT에서 0.980이었다. 결론: NIKf-BUT와 NIKav-BUT는 재현성이 확인되었다. NIKav-BUT는 FBUT와 유의한 차이가 없었으며, 양의 상관관계를 만족하였다. 높은 진단력을 보인 NIK-BUT는 안구건조증 정도를 나타내는 새로운 지표로 유용하게 이용될 수 있을 것으로 생각된다.

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 keratograph 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.