Abstract
Purpose :
Meibomian gland dysfunction (MGD) affects tear film stability, causing ocular irritation and dry eye. We conducted a prospective clinical study that included evaluating the tear film lipid layer thickness (LLT) in subjects with increasing severity of MGD.
Methods :
In an exploratory clinical trial (NCT01979887), participants were grouped by MGD disease severity in accordance with previously described diagnostic criteria and severity grading. Tear film LLT was measured with the LipiView interferometer (J&J Vision, Irvine, CA, USA). Pairwise comparisons of LLT among cohorts were done using the ANOVA model with cohort as a factor. Two subject visits were included in the study: Enrollment/Day 1 and Exit/Day 22. All statistical comparisons were made at the α = 0.05 level without the multiplicity adjustment.
Results :
The mean (SD) tear film LLT at Enrollment/Day 1 Non-MGD, Mild/Moderate MGD, and Severe MGD were 75.86 (15.466) nm, 72.88 (15.486) nm, and 73.86 (20.088) nm, respectively. The mean (SD) tear film LLT at Exit/Day 22 for Non-MGD, Mild/Moderate MGD, and Severe MGD were 68.10 (20.753) nm, 70.91 (17.888) nm, and 69.25 (19.049) nm, respectively. The mean (SD) tear film LLT scores across all cohorts was 73.83 (17.023) nm at Enrollment/Day 1 and 69.71 (18.168) nm at Exit/Day 22. No significant differences were noted between MGD cohorts in tear film LLT at both Enrollment/Day 1 and Exit/Day 22.
Conclusions :
Previously reported data from this clinical trial noted quantitative differences in lipid composition in meibum secretions across 3 cohorts. In brief, we demonstrated that molar ratios of cholesteryl ester to wax ester were lowest, and aldehyde to wax ester were highest in the severe MGD cohort. Given that the LLT did not differ between cohorts using a rigorous severity grading system for MGD, the quantity of lipid in the tear film as measured by the LipiView may not be as critical as the quality of the lipid composition in the tear film, which may be more related to tear film instability.
This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.