Microbial distributions in the conjunctiva and lacrimal sacs of patients with chronic dacryocystitis in a tertiary hospital

Abstract

Background: The aim was to clarify the distributions of bacteria in the conjunctival sac and lacrimal sac in patients with chronic dacryocystitis.

Methods: In total, 297 (322 eyes) chronic dacryocystitis patients who underwent nasal endoscopic dacryocystorhinostomy (EN-DCR) were included. Conjunctival sac secretions from the affected eye were collected preoperatively, and lacrimal sac retention fluid from the affected side in the same patient was collected intraoperatively. Bacterial culture and drug sensitivity testing were performed to determine bacterial distributions.

Results: In total, 127 bacterial isolates (49 species) were detected in 123 eyes in the conjunctival group, with a positivity rate of 38.2% (123/322); 85 bacterial isolates (30 species) were detected in 85 eyes in the lacrimal sac group, with a positivity rate of 26.4% (85/322). The positivity rates were significantly different (P = 0.001) between two groups. The gram-negative bacilli proportion in the lacrimal sac group (36/85, 42.4%) was significantly higher than that in the conjunctival sac group (37/127, 29.2%) ( P = 0.047). Positive conjunctival sac secretion culture (123/322) was significantly associated with increased ocular secretion (281/322, 87.3%) (P = 0.002). Among the culture-positive bacteria in the conjunctival sac group and the lacrimal sac group, 30/127, 23.6% and 43/127, 26.7% and 21/85, 24.7% and 20/85, 23.5% were resistant to levofloxacin and tobramycin, respectively.

Conclusions: This study illustrated differences in bacterial distributions between conjunctival sac secretions and retained lacrimal sac fluid in chronic dacryocystitis patients, with a higher proportion of gram-negative bacilli in lacrimal sac secretions. The ocular surface flora in chronic dacryocystitis patients is partially resistant to levofloxacin and tobramycin, which need to be considered by ophthalmologists.

Keywords: Antibiotic resistance; Bacterial distribution; Chronic dacryocystitis; Conjunctival sac; Lacrimal sac.