Children (age 0-14 years) with congenital lacrimal stenosis in whom probing and intubation of the lacrimal drainage system is indicated are included the study after informed written consent by their parents. Microbiological specimens are taken bilaterally from conjunctiva and nasal mucosa during the two procedures under general anaesthesia (insertion and removal of the silicon intubation) and from the silicon tube after removal. Specimens are examined for bacterial contamination. Microbiological findings are correlated with clinical data about the further clinical course and especially the success of the surgical treatment.
Children with congenital lacrimal stenosis are treated by probing and intubation of the lacrimal drainage system.~Hypothesis: Microbiological findings at the time of insertion and removal of the silicon intubation have an influence on the clinical outcome and success rate of the surgical treatment. Microbiological specimens are taken from conjunctiva and nasal mucosa during the two procedures under general anaesthesia and from the silicon tube after removal and examined for bacterial contamination.