title: [Impact of lacrimal obstruction type on the efficacy of probing for congenital nasolacrimal duct obstruction].
abstract: OBJECTIVE
  To explore the impact of lacrimal obstruction type on the efficacy of lacrimal probing in the treatment of congenital nasolacrimal duct obstruction.
  
  
  METHODS
  We conducted a retrospective study in which 872 eyes of 741 children with congenital nasolacrimal duct obstruction underwent nasolacrimal duct probing under superficial anesthesia. Two types of obstructions were encountered during probing, i.e. simple and complex. They were divided into early (4 - 12 months) and late (1 - 4 years) groups based upon the age at the time of initial probing. Those refractory to the first probing underwent a second probing 4 weeks later. The main observation criterion was the success rate of probing.
  
  
  RESULTS
  The success rate was 90.0% in early group versus 70.4% in late group (χ(2) = 38.527, P < 0.01). No significant difference existed in the cure rate of simple or complex obstruction between two groups (χ(2) simple = 0.054, P = 0.815, χ(2) complex = 1.705, P = 0.192). The proportion of simple obstruction was 94.4% in early group versus 62.2% in late group. Difference was statistically significant (χ(2) = 125.471, P < 0.01). The success rate of a second probing of simple obstruction was 61.9% in early group versus 68.2% in late group (χ(2) = 0.324, P = 0.569). The success rate of a second probing of complex obstruction was 19.2% in early group versus 5.7% in late group (Fisher's exact test, P = 0.125). For either group, the success rate of a second probing of simple obstruction was higher than that of complex obstruction (χ(2) early group = 16.100, P < 0.01; χ(2) late group = 25.186, P < 0.01).
  
  
  CONCLUSIONS
  Unsuccessful probing may result from the selection of complex obstructions. Probing should remain the first-line treatment in children above 1 year of age. The success rate with a second probing was significantly lower in patients of complex obstruction. Other surgical interventions, such as silicone tube intubation or balloon dacryocystoplasty, should be recommended instead of repeated probing for the patients of complex obstruction if an initial probing fails.
authors.affiliation: Department of Ophthalmology, Guangzhou Women & Children's Medical Center, Guangzhou, China. zhaowei7163@yahoo.com.cn
authors.forename: Wei
authors.initials: W
authors.lastname: Zhao
authors.forename: Li-li
authors.initials: LL
authors.lastname: Chen
authors.forename: Dao-man
authors.initials: DM
authors.lastname: Xiang
mesh_terms: D002675:Child, Preschool; D003608:Dacryocystorhinostomy; D005260:Female; D006801:Humans; D007223:Infant; D007440:Intubation; D007767:Lacrimal Duct Obstruction / Q000145:classification* / Q000151:congenital; D008297:Male; D012189:Retrospective Studies; D016896:Treatment Outcome