Evaluation of tear film function by Oculus Keratograph 5M and IDRA ocular surface analyser.

Purpose: The aim of this study was to evaluate the function of tear film with Oculus Keratograph 5M (Oculus K5M) and IDRA ocular surface analyser (IDRA), analyse their consistency and explore the potential of IDRA in the diagnosis of dry eye disease (DED).

Methods: This cross-sectional study enrolled 36 participants (DED group, 14 eyes; non-DED group, 22 eyes). The parameters of tear film function, including the first noninvasive breakup time (fNIBUT), average NIBUT (aNIBUT), tear meniscus height (TMH), lipid layer thickness (LLT), lipid layer colour (LLC), lipid layer uniformity (LLU), morphology of meibomian glands (MGs) and MG loss, were obtained with Oculus K5M and IDRA. The consistency of parameter measurements between the two devices was evaluated.

Results: All the parameters except LLT, which can be measured only by IDRA, were not significantly different between the two instruments in DED eyes. However, IDRA reported lower values of fNIBUT, aNIBUT and TMH as well as higher MG loss scores in non-DED eyes than Oculus K5M did (p < 0.001, < 0.001, = 0.002, and = 0.002, respectively). Further regression analysis revealed that aNIBUT and LLT measured by IDRA were the optimal parameters for diagnosing DED (OR = 0.567 and 0.845, p = 0.057 and 0.043, respectively), and their combination had the strongest diagnostic potential (AUC = 0.841, sensitivity = 85.7%, and specificity = 77.3%).

Conclusion: As a user-friendly noninvasive device, the tear film function parameters measured by IDRA were highly consistent with those measured by Oculus K5M in DED patients. The combination of aNIBUT and LLT measured by IDRA had the best diagnostic accuracy for DED.