Physiological recanalization of the lacrimal passage normalizes conjunctival flora

This prospective study describes the conjunctival bacterial flora found in eyes with lacrimal passage obstruction that underwent dacryoendoscopic recanalization.

Study design

Researchers enrolled 150 eyes with lacrimal passage obstruction. Dacryoendoscopic recanalization involved physiological recanalization of the entire lacrimal passage under dacryoendoscopic observation followed by silicone stent intubation. Conjunctival scraping was performed before and 4 months after the procedure and sent for culture.

Outcomes

After surgery, the number of samples exhibiting positive bacterial growth decreased from 42% to 26%. Of the samples with positive preoperative growth, 11% had mixed cultures with 2 or 3 strains. Although a total of 20 strains were isolated at baseline, only 9 were detected postoperatively. At the same time, the presence of native conjunctival flora—such as coagulase-negative Staphylococci and Corynebacterium—increased from 47% to 81%. There was no difference in the rate of bacterial isolation based on the location of lacrimal obstruction (punctal, canalicular, or nasolacrimal duct).

Limitations

The study was limited by its noncomparative study design. It is possible that the use of postoperative antibiotics may have affected the microflora. A randomized, prospective study comparing patients with and without surgery would give the results more power. Because this study did not demonstrate a superiority of dacryoendoscopic recanalization to traditional dacryocystorhinostomy (DCR) surgery, a randomized, prospective study comparing these 2 techniques would be beneficial.

Clinical significance

Although lacrimal outflow obstruction surgery traditionally is performed to improve symptoms of tearing, this study demonstrated the added benefit of decreasing culture positivity and number of microorganism strains detected in the conjunctival sac. This has previously been shown in patients undergoing traditional DCR surgery, but the authors demonstrated that recanalization of the native lacrimal duct has a similar effect. These findings illustrate how adequate lacrimal drainage can help control conjunctival bacterial flora. This has implications for chronic bacterial conjunctivitis and highlights the importance of establishing adequate lacrimal drainage prior to ocular surgeries to decrease the risk of postoperative infection.