RESUMO
To determine bacterial flora of the conjunctiva and lacrimal sac in adult patients with nasolacrimal duct obstruction [NLDO] in comparison with normal flora. This study included 40 consecutive adult patients with NLDO and 40 age- and sex matched healthy controls. Specimens for bacterial culture were obtained from the involved and normal conjunctiva preoperatively and from the lacrimal sac of the involved eye at the time of dacryocystorhinostomy in the patients as well as from the conjunctiva of the control group. Culture growth and colony count were determined in each group. Conjunctival cultures were positive in 100% of involved eyes and 97.5% of sound eyes in the patients as well as in 82.5% of controls. The most prevalent organisms were Staphylococcus epidermidis and S. aureus in both NLDO and control groups. The isolated organisms were the same in 90% of specimens obtained from the sac and conjunctiva of the involved eyes. Mean colony counts were significantly higher in the lacrimal sac and conjunctival culture of the involved eye as compared to the normal side and the control group. The predominant microorganism is S. epidermidis in normal ocular surface but S. aureus in eyes with NLDO. Conjunctival culture can be used as a predictor of lacrimal sac flora in cases with NLDO