Abstract
PURPOSE: Meibomian gland dysfunction (MGD) is a common disease, yet there is no standard clinical definition. This study explored the frequency and characteristics of MGD in dry eye disease (DED) using different clinical definitions. METHODS: A secondary analysis of data collected from the DREAM© study participants (n = 535) with moderate-to-severe DED was undertaken. Three common MG clinical features; plugging, secretion quality, and MG atrophy grade, either separately or in combination were used to create MGD definitions. The frequency of MGD, defined by the per eye findings, was reported. Demographic characteristics were compared between those with and without MGD. RESULTS: The frequency of MGD in DED varied from 12 % (gland plugging, plus poor secretion quality plus gland atrophy) to 55 % (gland plugging alone) of eyes. Older age was associated with MGD when atrophy-based definitions were used (p < 0.001) but was not associated with MGD definitions using plugging or secretion quality (p > 0.05). After adjustment for age and between-eye correlations, MGD frequency was higher in women for definitions based on lower lid gland atrophy (adjusted p < 0.05). Hispanic or Latino ethnicity was more commonly associated with MGD than other ethnicities (adjusted p < 0.001), for definitions based on plugging and secretion quality. CONCLUSION: The frequency of MGD in DED varied with MGD definition. The highest frequency occurred where MGD was defined as lower eyelid gland plugging. Gland atrophy increased with age. The variation in disease frequency has implications for clinical diagnosis and determining efficacy assessment in intervention studies.