AIM: To investigate the diagnostic value of Keratograph 5M for the diagnosis of dry eye(dry eye)tear film grading.

METHODS: Totally 100 eyes diagnosed with dry eye by conventional means and 40 non-dry eye eyes with suspected dry eye at the same time were enrolled through OPC. The immediate ocular surface parameters of the above cases were collected by the K5M ocular surface analyzer, including the first tear film rupture time(NIBUTf), the average tear film rupture time(NIBUTav), and the tear river height(TMH)which were utilized to evaluated the diagnostic efficacy of K5M compared to routine ocular surface examination on the index of dry eye tear film.

RESULTS: The comparison of NIBUTf, NIBUTav and TMH between dry eye group and non-dry eye group by K5M eye surface comprehensive analyzer showed statistically significant differences(all P<0.05). The coincidence rate between the NIBUTf of K5M ocular surface analyzer and the BUT of routine diagnosis was 78.6%, and the area under the ROC curve as well as the standard error were 0.042 and 0.795(P<0.01)with 95% confidence interval(0.712, 0.878); The coincidence rate between NIBUTav of K5M and BUT of routine examination diagnosis was 73.6%, and the area under the ROC curve as well as the standard error were 0.853 and 0.033(P<0.01), with 95% confidence interval(0.788, 0.917).The coincidence rate between TMH of K5M and the SⅠt of conventional diagnosis was 87.9%, and the area under the ROC curve as well as the standard error were 0.795 and 0.044(P<0.01), with the 95% confidence interval(0.709, 0.880). The sensitivity, specificity, correctness index, positive likelihood ratio, negative likelihood ratio, and odds ratio of the exploratory diagnosis of dry eye by NIBUTf combined with TMH were 98, 40, 38, 1.63, 0.05, and 32.6%, respectively. The sensitivity, specificity, correctness index, positive likelihood ratio, negative likelihood ratio, and odds ratio of the exploratory diagnosis of dry eye by NIBUTav combined with TMH were 86, 75, 61, 3.44, 0.187, 18.39%, respectively.

CONCLUSION: K5M ocular surface analyzer can provide accurate and reliable diagnostic value for single tear film index grading diagnosis of dry eye; compared with TMH combined with NIBUTav, TMH combined with NIBUTf was more sensitive but less specific in diagnosing dry eye.