Comparison of treatment effect across varying severities of meibomian gland dropout.

Purpose: Better understanding of the pathophysiology of meibomian gland dysfunction (MGD) has provided the opportunity to develop treatments which could be tailored for specific presentations of MGD. This study sought to directly compare treatment effectiveness for three current therapies across differing levels of MG dropout.
Methods: Subjects (n=81), grouped by infrared meibography dropout proportions, into either no (control), mild, or pronounced MG dropout, were randomised to receive treatment with a latent heat device (n=25), liposomal spray (n=28), or heated warm compress (n=28). A battery of tear film measures was performed, pre- and post-application of treatment, and compared by treatment type and MG severity.
Results: Symptoms correlated with MG dropout proportions (r=0.618, p<0.001). Following treatment, non-invasive tear breakup time improved (p=0.010), independent of treatment type (p=0.131). The improvement was significant only in the pronounced MGD group (+4.32 ±1.15s, p=0.008), however, following treatment, the mild group was no longer distinct from the control group (p=0.843). Lipid layer grade (LLG) also improved following treatment (p<0.009), but again was not specific to treatment type (p=0.349). All three severity groups showed an improvement in LLG, with 49.3% of participants showing an improvement of at least one grade, and none showing decreased LLG.
Conclusions: Increased LLG across all three treatment groups suggests that all methods increase meibum outflow to the tear film, resulting in a thicker lipid layer after treatment. These results suggest that all three treatments are effective in improving tear film quality, independent of MGD severity based either on symptoms or based on gland dropout.
(Copyright © 2017 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.)