Abstract
Purpose :
A chalazion is chronic inflammatory granuloma primarily caused by the retention of a meibomian gland secretion, and it has generally been believed that it is a non-infectious form of inflammation. However, in meibomitis-related ocular surface inflammation, e.g., meibomitis-related keratoconjunctivitis, which is reportedly caused by Propionibacterium acnes (P. acnes), patients often have a past history of chalazion. The purpose of this present study was to evaluate the role of P. acnes in the pathogenesis of chalazion.
Methods :
This study involved 8 patients (age range: 3-37 years) who underwent surgery to remove a chalazion cyst. In 4 of the 8 patients, solid meibum in the chalazion was obtained at the time of surgery, stored in chloroform/methanol, and analyzed using gas chromatography mass spectrometry for composition analysis. The chalazion tissue of each patient was soaked in 10% buffer formaldehyde, embedded in paraffin, sectioned, and stained by hematoxylin and eosin as well as by the monoclonal antibody of P. acnes.
Results :
Our findings showed positive for P. acnes in 2 patients with typical granuloma formation with epithelioid cells and polynuclear giant cells, which had not been treated with antimicrobial agents and/or steroids. On the other hand, they showed negative for P. acnes in the other 6 patients without typical granuloma formation treated with antimicrobial agents and/or steroids. Compared to that of the 12 normal control subjects (NC) which we previously reported (ARVO 2014), analysis of the fatty acid composition of the solid meibum in chalazion revealed a significant increase of straight-chain saturated fatty acid (17.7%, NC: 2.8%) (p<0.05) and a significant decrease of monounsaturated fatty acids (45.0%, NC: 51.7%) (p<0.05).
Conclusions :
The findings of this study show that P. acnes proliferation in a meibomian gland could be a trigger for the pathogenesis of chalazion and that P. acnes lipase could change the lipid composition of meibum, thus resulting in the chronic inflammation.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.