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Objective: The aim of this study was to evaluate changes in the ocular surface and nasal microbiota after external dacryocystorhinostomy (DCR) in patients with unilateral nasolacrimal duct obstruction (NLDO).
Methods: This prospective study included 68 eyes of 34 patients. Prior to external DCR, nasal and conjunctival smears were obtained from the affected eye and healthy contralateral eye.
Results: Ocular surface cultures were positive in 19 (55.9%) of the NLDO eyes and 4 (11.8%) of the healthy eyes (p<0.001). The most frequently detected organism was methicillin-sensitive coagulase-negative staphylococci (MSCNS), which accounted for 45.8% of ocular surface isolates and 45.1% of nasal isolates. Pathogenic microorganisms (Citrobacter freundii and Candida krusei) were only detected in 2 NLDO eyes before DCR, and these microorganisms did not grow in any eye at any time after surgery. Although no reproduction was observed in repeated swabs, MSCNS growth was observed in 3 eyes (12.5%) postoperatively. The median postoperative time to ocular surface microbiota normalization was 2 weeks. Microorganisms isolated from ocular and nasal cultures were most resistant to penicillin, with rates of 57.1% and 73.3%, respectively.
Conclusions: Eyes with NLDO showed significantly greater microorganismal growth in ocular surface cultures than the healthy eyes. A safety margin of at least 2 weeks after successful external DCR is required for patients scheduled for intraocular surgery. Our susceptibility data suggest that clinicians should avoid penicillin when selecting antibiotics for patients with NLDO.
Cite this article as: Aslan F, Doğan B, Şahin C. Ocular surface microbiota changes after external dacryocystorhinostomy: a “chicken or egg” problem. B-ENT 2020; 16(1): 19-24.