Background: Congenital nasolacrimal duct obstruction (CNLDO) is one of the
leading causes of epiphora in infants, in which antibiotics are usually used as
a conservative therapy in the first year. Objectives: This study aimed to
evaluate the conjunctival bacterial flora in fellow eyes of patients 1-5 years old
with unilateral NLDO and its changes after successful probing surgery.
Methods: This prospective case-control study was conducted on children
between 1-5 years old with unilateral NLDO with successful probing surgery
in 2021. Before probing procedure and postoperative sampling from the
conjunctiva of the eyes continued weekly until the colony count became
negative or normal. Positive culture (clinically significant growths), colony
count, and detected bacteria types reported. Results: The positive culture of
conjunctival bacteria was observed in 71 (73.96%) in the case group and 35
eyes (36.46%) in the control group (P<0.0001). Most bacterial species in the
case and control groups were gram-positive (75.61% and 82.86%, respectively;
P=0.181). The most common isolated microorganisms in both groups were
Staphylococcus epidermidis (54.95% and 51.43%) and Staphylococcus aureus
(16.9% and 21.43%). The mean normalization time of bacterial culture was
1.92±0.54 weeks (between 1-3 weeks). The time for normalization of cultured
bacteria was significantly related to the initial colony count≥1000 and the
presence of a silicone tube (P<0.0001). Conclusions: Present study shows that
gram-positive organisms with the predominance of Staphylococcus spp. were
the significant conjunctival bacterial flora in pediatrics with NLDO. These
findings could be helpful for management and appropriate antibiotic
selection for treating of NLDO in our region.
Keywords: Congenital nasolacrimal duct obstruction, Bacteriology, Lacrimal
sac, Conjunctiva
