Intra- and interobserver reliability of ocular surface analyzer LacryDiag

To invastigate intra- and interobserver reliability of interferometry, tear meniscus height (TMH) measurement and meibography (MBG) of an ocular surface analyzer, LacryDiag (Quantel Medical, France). Five consecutive measurements and subsequent analysis of interferometry, TMH, and MBG were recorded by two examiners using the LacryDiag. To assess intra- and interobserver reliability, we used Cohen's kappa for categorical variables (interferometry), or intraclass correlation coefficient for continuous variables (TMH, MBG). Thirty eyes of 30 examinees were included. For both observers, there was excellent intraobserver reliability for MBG (0.955 and 0.970 for observer 1 and 2, respectively). Intraobserver reliability for observer 1 was substantial for interferometry (0.799), and excellent for TMH (0.863). Reliability for observer 2 was moderate for interferometry (0.535) and fair to good for TMH (0.431). Interobserver reliability was poor for interferometry (0.074) and fair to good for TMH (0.680) and MBG (0.414). LacryDiag ocular surface analyzer in our study proves to be a reliable noninvasive tool for the evaluation of TMH and MBG. As for interferometry, poor interobserver reliability, fair to good intraobserver reliability for observer 1, and moderate for observer 2, leave room for improvement.