Abstract
Objective
To evaluate the corneal endothelial layer characteristics in the meibomian gland dysfunction (MGD) cases and compare them to those of the healthy controls.Study design
Cross-sectional.Methods
100 eyes from 50 MGD cases and 66 eyes from 33 healthy controls were evaluated in this study. The ocular surface disease index (OSDI), Schirmer's test, tear break-up time (TBUT), tear meniscus height, and MGD staging were evaluated as the subjective and objective parameters of dry eye disease (DED) and MGD. The corneal endothelial cell density (ECD), coefficient of variation in endothelial cell size (CV), and hexagonal cells proportion (HA) were evaluated using the corneal specular microscopy. Linear mixed-effect models (LMMs) were used to compare endothelial parameters between groups.Results
The mean age in the MGD group was 56.9 years, and in the controls, 44.3 years. Although the age difference was significant, it was treated as a covariate in the LMM to adjust for age differences across groups. The adjusted mean ECD was 183 cells/mm2 lower in the MGD cases than in the controls. However, the difference was marginally statistically insignificant (95%CI: -371 to + 3, p = 0.055). On the other hand, within-group analysis showed that the more advanced stages of MGD have lower ECD (Mean difference for stage 4 vs. 1: -745 cells/mm2, and stage 3 vs. 1: -610 cells/mm2). The CV showed no significant difference between the groups. Adjusted HA means were 40.97% in MGD versus 36.04% in controls (mean difference = + 4.93, 95% CI: +1.31 to + 8.55). However, the HA difference does not appear clinically significant and may be due to inter-measurement variability in specular microscopy.Conclusion
Our findings suggest a potential association between MGD severity and corneal endothelial parameters, particularly endothelial cell density, although this relationship is modest and influenced strongly by age.