Conjunctival Microbiota May Explain Ocular Rosacea Pathogenesis

Differences between the conjunctival microbiota in individuals with ocular rosacea and individuals without the disease may provide an explanation for the disorder’s pathogenesis, according to research published in Eye and Contact Lens.

“Rosacea is an inflammatory ocular condition, and oral and topical antibiotics have been reported to be beneficial in its treatment; therefore, it can be suggested that changes in ocular microbiota may play a role in this disease’s pathogenesis,” the study authors explain.

Researchers examined the conjunctival microbiota of 33 patients with ocular rosacea (mean age, 38.9 years; 72.73% women) and 30 control group participants (mean age, 35.8 years; 63.33% women) admitted from a dermatology clinic. Study participants underwent tear breakup time (TBUT), Schirmer score, and blepharitis symptoms score (BLISS) assessments and provided bacterial culture samples.

Bacterial cultural positivity was similar among individuals with ocular rosacea and control group participants (39.4% vs 33.3%; P =.618), the report shows. However, the most frequent bacteria types differed among the groups. The most common bacteria noted among individuals with ocular rosacea was micrococcus luteus (18.2%) and staphylococcus epidermidis (20.0%) was most commonly observed in control group individuals.  

Patients with ocular rosacea had worse TBUT and Schirmer scores, and higher BLISS (P= .005, P= .007, and P= .001, respectively) compared with control group participants. Individuals with ocular rosacea who had available conjunctival culture-positive results had higher BLISSs (8.0) compared with participants with negative results (4.7±2.3; P <.001). 

“In patients with [ocular rosacea] as corneal involvement forms, development of punctate epitheliopathy, marginal keratitis, neovascularization, scarring, and corneal stromal thinning can be observed,” according to the researchers. “These inflammatory changes might be related to the change in ocular microbiota or a change in the microbiota might be related to these inflammatory results.”

Study limitations include a cross-sectional design and the absence of lid margin and skin samples from patients with ocular rosacea.