Agreement and repeatability of ocular surface function using the S390L Firefly WDR slitlamp compared with Keratograph 5M

Abstract

To evaluate the agreement and repeatability of the S390L Firefly WDR slitlamp (S390L WDR+D130, MediWorks, Shanghai, China)   in tear film-related parameters measurement compared with Keratograph 5M(K5M) (Oculus Optikgeräte GmbH, Wetzlar, Germany). This prospective study assessed tear film parameters, including first non-invasive tear break-up time (NIBUTf), average non-invasive tear break-up time (NIBUTav), and tear meniscus height (TMH) using the S390L Firefly WDR slitlamp and K5M. Bland-Altman (BA) plots and the correlation coefficient r were used to assess the agreement of tear film parameters of two ocular surface analyzers. Intraclass correlation coefficient (ICC) was used to evaluate the repeatability of the S390L Firefly WDR slitlamp and K5M. Forty-four subjects from Shenyang He Eye Specialist Hospital were recruited in this study. There were no significant differences in the paired comparisons of NIBUTf, NIBUTav, and TMH (p > 0.05). The BA plots analysis showed a good agreement between the two devices for the NIBUTf (95% LoA, − 2.7 to 2.6), NIBUTav (95% LoA, − 4.5 to 3.6) and TMH (95% LoA, − 0.05 to 0.04). ICC of NIBUTf, NIBUTav, and TMH between the two measurements using S390L Firefly WDR slitlamp was 0.89, 0.84, and 0.98, respectively. The tear film-related parameters measurement of S390L Firefly WDR slitlamp had good repeatability and acceptable agreement with K5M. This study suggested a novel technique S390L Firefly WDR slitlampcan be considered an alternative to K5M in clinical settings, with an acceptable level of intrasession repeatability for clinical evaluation of tear film parameters.