Meibomian Gland Dysfunction (MGD) in the Dry Eye Assessment and Management (DREAM©) study

Abstract

Purpose : MGD is a common condition that disturbs the ocular surface ecosystem, yet there is no standard definition for MGD. The prevalence of MGD ranges widely from 18% to 78% from the studies using different definitions. This study aimed to analyze the frequency and characteristics of MGD in moderate-to-severe dry eye disease (DED) participants from the DREAM© study using different MGD definitions.

Methods : Three common MG clinical features; plugging, quality of meibum, & MG dropout or atrophy (graded on meibography images) either separately or in combination were used to create 9 MGD definitions (Tables 1 & 2). DREAM© study participants with moderate-to-severe dry eye were classified into MGD & no-MGD groups, and their differences in demographics, DED signs & symptoms, and biomarkers (from impression cytology (IC), tears and serum samples) were compared between the MGD groups for each of the 9 definitions.

Results : Based on the 9 different MGD definitions, the frequency of MGD in the DREAM© study participants (n=535) varied from 50% to 94%. Older age was associated with a higher risk of MGD when atrophy-based definitions were used (p<0.001) but age was not associated with MGD defined based on plugging or quality of meibum (p>0.05). Sex was not associated with MGD for all 9 definitions (p>0.05). Compared to their counterparts, subjects with MGD, defined by plugging and quality of meibum had significantly worse contrast sensitivity, shorter tear break-up time, lower IC: WBC count, T_helper cells, T_regulatory cells, tear cytokines (IL-1, IL-10, TNF) and serum ω6 to ω3 ratio (p<0.05), but significantly higher eyelid margin erythema, systemic fatty acid docosahexaenoic levels and longer Schirmer wetting length (p<0.05). MGD defined based on atrophy were associated with a higher corneal staining score, bulbar redness score, tear meniscus height, and tear cytokines levels (IL-6, TNF) but lower HLA-DR gated levels (p<0.05).

Conclusions : The frequency and characteristics of MGD in the DED cohort of the DREAM© study varied greatly by different definitions, suggesting that how MGD is defined may greatly impact the study cohort and clinical trial outcomes. Trials of MGD interventions need to select appropriate endpoints based on the mechanism of action of the intervention.

This abstract was presented at the 2024 ARVO Annual Meeting, held in Seattle, WA, May 5-9, 2024.

 

Grading of plugging, quality of meibum and MG loss or dropout.

 

Definition and frequency of MGD based on 9 definitions. See Table 1 for details.