Measurement of the Lid Margin Thickness in Meibomian Gland Dysfunction with Vernier Micrometer

Abstract

Introduction: To investigate the lid margin thickness (LMT) from the posterior lash line to the mucocutaneous junction at the middle position in adults with and without meibomian gland dysfunction (MGD) by vernier micrometer (VM).

Methods: This is a cross-sectional, observational study. A hundred eyes from 100 volunteers aged 20 to 79, including 56 normal participants and 44 participants with MGD, were recruited. Measurements of the LMT by VM were performed by the same person.

Results: The mean age of 56 normal subjects (24 males and 32 females) and 44 MGD subjects (16 males and 28 females) was 40.0 ± 13.2 years and 42.7 ± 17.1 years, respectively. There was a significant difference in the upper LMT between normal and MGD subjects (1.36 ± 0.25 vs. 1.60 ± 0.27 mm, P < 0.001), but not in the lower LMT (1.0 ± 0.23 vs. 1.10 ± 0.28 mm, P = 0.07). In both normal and MGD subjects, the upper or lower LMT was significantly positively correlated with age (P < 0.05), and the upper LMT was greater than the lower LMT (P < 0.001). In addition, the lower LMT in MGD subjects was significantly positively correlated with meibum expressibility (r_s = 0.35, P = 0.02).

Conclusions: The LMT was closely related to age and could be an important indicator for detecting MGD. Furthermore, we found that the upper LMT was greater than the lower LMT, and the lower LMT in MGD subjects seemed to be related to meibum expressibility.

Keywords: Lid margin thickness; Meibomian gland dysfunction; Meibum expressibility; Vernier micrometer.

Fig. 1

Measurement of the upper LMT by a vernier micrometer under the slit-lamp microscope. The yellow arrow stands for the MCJ (specular reflection); the blue line stands for the posterior eyelash line; the red double arrows stand for the LMT; the two white thick arrows stand for a vernier micrometer

Fig. 2

Agreement between the first and second measurement of the lower LMT. Bland-Altman plots demonstrated that 30 of 30 spots were within 95% limits of agreement (95% LoA); the maximum difference was 0.21 mm, and the arithmetic mean was 0.02 mm

Fig. 3

Association between the LMT and age in both normal and MGD subjects. A Upper and lower LMTs were significantly positively correlated with age (r_s = 0.50 and 0.77, P = < 0.001 and < 0.001, respectively). B Upper and lower LMTs were also significantly positively correlated with age (r_s = 0.42 and 0.68, P = 0.005 and < 0.001, respectively)