Abstract
Purpose:
To determine the association of Demodex folliculorum and Demodex brevis with chalazia and identify associated histopathologic changes.
Methods:
In a retrospective case-controlled study, 81 paraffin-embedded ectropion/entropion wedge resection specimens were obtained from an ocular pathology lab, excised between 1990 and 2013. Cases with tissue less than 5 x 4 x 1 mm or an additional pathologic process unrelated to senile ectropion/entropion were excluded. Serial sections were stained with hematoxylin and eosin. Demodex folliculorum and Demodex brevis were quantified by light microscopy in specimens with chalazia, n = 40 and without chalazia, n = 41 and associated histopathologic changes in the eyelid were recorded.
Results:
There was a significantly greater mean number of Demodex folliculorum in biopsies with chalazia, when compared to biopsies without chalazia (5.55 vs. 2.68, P = 0.044). The presence of Demodex folliculorum was strongly associated with hair follicle duct dilatation and hyperkeratinization and with perifollicular non-granulomatous inflammation (P = 0.00). Hair follicle duct dilatation and hyper-keratinization were also independently associated with chalazia (P = 0.040). We observed Demodex brevis only in the meibomian glands of specimens with chalazia (mean 0.342), but this finding did not reach statistical significance, p= 0.068.
Conclusions:
While we cannot establish causality between Demodex and chalazia, our findings suggest that Demodex folliculorum indirectly may be involved in the pathogenesis of chalazia via its effect on the anterior eyelid margin.
Keywords: 486 cornea: tears/tear film/dry eye •
638 pathology: human •
419 anatomy