The influence of microorganisms on early relapses after external dacryocystorhinostomy.

Purpose: Understanding the influence of microorganisms in patients with acquired nasolacrimal duct obstruction (NLDO) and investigating their effect on recurrence after external dacryocystorhinostomy (DCR).

Methods: This prospective study included 50 patients. Evaluations were made before, on the first postoperative day and monthly after DCR. Nasolacrimal silicon tubes (NST) were removed after three months. Before the DCR, swab samples were taken from both hands and lower conjunctival fornices and from the lacrimal sac during the first DCR and from the relapsed cases during the second DCR.

Results: Growth was observed in 90 (45%) cultures out of 200 and a total of 23 different strains were identified altogether. Staphylococcus aureus (40%) and Streptococcus pneumoniae (28%) were dominantly isolated which were all resistant to penicillin, tetracycline and erythromycin. Lacrimal syringing (LS) was successful in patients (100%) on the first postoperative day. After three months, before NST removal, purulent discharge from the punctum was observed in five patients, and blockage was detected by LS. S. pneumoniae was isolated from all five patients' obstructed side conjunctival cultures. Additionally, from their lacrimal sac, S. pneumoniae (4 patients), Capnocytophaga gingivalis, and Candida spp. (1 patient) strains were isolated. S pneumoniae was isolated in four out of five patients from the ipsilateral conjunctival and lacrimal sac cultures which obtained from the subsequent DCR.

Conclusion: Our results showed that S. pneumoniae was an isolated and persistent strain in cases with early recurrence even after a successful DCR.