Statistical Comparison of four Groups: Healthy, Aqueous Tear Deficiency (ATD), obvious obstructive Meibomian Gland Dysfunction (MGD), and Non-obvious Obstructive MGD (NOMGD) Patients.

* Average ± standard deviation.†Median (mode) ± Average Absolute deviation. Mode was added if different from the median.OSDI = Ocular Surface Disease ndex; FBUT = fluorescein break-up time; FSOS = fluorescein staining of the ocular surface;SVST = standardized visual scale test; CoL = clearance/turnover of lipids in human tears; TDI = tear dysfunction index; Obstructive MGD = (obvious) obstructive meibomian gland dysfunction; U = post-hoc Mann-Whitney U tests with Bonferroni correction; K = Kruskal–Wallis statistic; n.s. = not significant;Statistical Comparison of four Groups: Healthy, Aqueous Tear Deficiency (ATD), obvious obstructive Meibomian Gland Dysfunction (MGD), and Non-obvious Obstructive MGD (NOMGD) Patients.