The thyroid controls countless bodily functions, including the production of meibum and aqueous tears. If the thyroid is sluggish, the cells that turn into meibum do not die and are not replaced with sufficient frequency, leading to evaporative dry eye and meibomian gland dysfunction (MGD). Lacrimal gland activity can slow down, leading to aqueous tear deficiency.
References
Thyroid disease and sebaceous function
S K Goolamali, D Evered, S Shuster
British Medical Journal
1976 Feb 21; 1(6007): 432–433.
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The International Workshop on Meibomian Gland Dysfunction: report of the Subcommittee on Anatomy, Physiology, and Pathophysiology of the meibomian gland
Knop E, Knop N, Millar T, Obata H, Sullivan DA.
Investigative Ophthalmology and Visual Science
2011 Mar 30;52(4):1938-78. doi: 10.1167/iovs.10-6997c. Print 2011 Mar.
PMID:21450915
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