Conjunctival Microbiota and Blepharitis Symptom Scores in Patients With Ocular Rosacea

Investigation of the relationship between blepharitis-related symptom scores, tear film functions, and conjunctival microbiota in patients with ocular rosacea (OR) compared with healthy controls was aimed.

Consecutive 33 eyes of 33 patients with OR who were admitted from the dermatology clinic and age-matched and gender-matched 30 healthy controls were included in the study. Tear breakup time (TBUT), Schirmer score, and blepharitis symptom score (BLISS) were recorded for each patient. For the bacteriological examination, bacterial culture was obtained by inoculating the samples on chocolate agar, blood agar, and fluid thioglycollate medium. The growth of different colonies of bacteria was identified using matrix-assisted laser desorption or ionization time-of-flight mass spectrometry.

Bacterial culture positivity was observed in 13 eyes (39.4%) in the patients with OR and 10 eyes (33.3%) in the controls ( P =0.618). Patients with OR showed worse TBUT and Schirmer scores, and higher BLISSs ( P =0.005, P =0.007, and P =0.001, respectively). Patients with OR with conjunctival culture-positive results showed higher BLISSs (8.0±4.7) compared with those with negative results (4.7±2.3; P <0.001). The most frequent bacteria was Micrococcus luteus (18.2%) in patients with OR and Staphylococcus epidermidis (20.0%) in the controls.

This pilot study showed that patients with OR had similar conjunctival culture positivity compared with healthy controls. However, the observation of different dominant bacterial species in conjunctival microbiota and the observation of worse BLISSs in patients with OR with positive culture might suggest a potential role of conjunctival microbiota in the pathogenesis of OR.