Although there are many presentations of meibomian gland dysfunction (MGD), one of the hallmark signs is the appearance of froth, foam or bubbles in the tear film.1 We’ve all seen this many times, and there really isn’t any other underlying cause. So when you see foam or froth in the tear film, you can safely make a diagnosis of MGD.
But, why does this frothing occur? Some experts believe that MGD causes the secretion of a foamy, surfactant-like material rather than healthy meibomian gland oil.2,3 Other clinicians believe that the frothy presentation is a result of saponification, where bacterial enzymes react with tear lipids to form a soapy discharge.4 Regardless, both theories attribute the fundamental cause to MGD.
So, it’s no wonder that patients with MGD complain of burning, stinging, redness and fluctuating vision—it’s like they have soap in their eyes!
1. Nien CJ, Massei S, Lin G, et al. Effects of age and dysfunction on human meibomian glands. Arch Ophthalmol. 2011 Apr;129(4):462-9.
2. Nicolaides N, Santos EC, Smith RE, et al. Meibomian gland dysfunction. III. Meibomian gland lipids. Invest Ophthalmol Vis Sci. 1989 May;30(5):946-51.
3. Lozato PA, Pisella PJ, Baudouin C. The lipid layer of the lacrimal tear film: physiology and pathology J Fr Ophtalmol. 2001 Jun;24(6):643-58.
4. Borchman D, Foulks GN, Yappert MC, et al. Human meibum lipid conformation and thermodynamic changes with meibomian-gland dysfunction. Invest Ophthalmol Vis Sci. 2011 Jun 1;52(6):3805-17. Print 2011 May.