The International Workshop on Meibomian Gland Dysfunction: Report of the Subcommittee on the Epidemiology of, and Associated Risk Factors for, MGD

Scientists have been interested in studying the secretions of the meibomian glands for many years, 1– 8 and diseases associated with the meibomian glands (e.g., cancers, posterior blepharitis) have been noted in the medical literature since at least the early part of the 20th Century. 9 –13 However, the term “meibomian gland dysfunction” (MGD) was only introduced by Korb and Henriquez in 1980. 14 The terminology “meibomian gland disease” was later introduced by Bron et al. 15 as an umbrella term to indicate any disease affecting the meibomian glands (see Definition and Classification). Although the etiology of MGD may differ from that of aqueous-deficient dry eye disease (which is due to insufficient lacrimal gland production), the two conditions share many clinical features, including symptoms of ocular surface irritation and visual fluctuation, altered tear film stability, and potential ocular surface compromise. When MGD is of sufficient degree, it may give rise to the second major subtype of dry eye disease, evaporative dry eye. 16 These subtypes are not mutually exclusive, as has been acknowledged. 16