title: Congenital nasolacrimal duct obstruction in premature children.
abstract: OBJECTIVE
  To determine the incidence of congenital nasolacrimal duct obstruction (CNLDO) in premature and full-term children.
  
  
  METHODS
  Medical records of 200 premature and 200 full-term children from July 2004 to November 2009 at the Peri-Peri Health Center were retrospectively reviewed. Fifty-three nasolacrimal ducts in 32 premature children (21 patients were bilateral) and 9 nasolacrimal ducts in 7 full-term children (2 patients were bilateral) diagnosed as having CNLDO were retrospectively examined.
  
  
  RESULTS
  Of the 200 premature children, 32 (16%) had CNLDO compared with 7 (3.5%) of the 200 full-term infants (P < .0001). Thirty premature infants and five full-term children underwent conservative treatment. Bilateral obstruction was found in all 3 extremely premature children (gestational age < 28 weeks), in 9 (69.23%) moderately premature children (gestational age of 28 to 31 weeks), in 9 (56.25%) mildly premature children (gestational age of 32 to 36 weeks), and in 2 (28.57%) full-term children (gestational age > 37 weeks).
  
  
  CONCLUSIONS
  This study reported a higher incidence of CNLDO in preterm infants when compared to full-term infants. This might be expected in light of the normal development of the nasolacrimal duct system, the patency of which normally occurs after the preterm infant is born.
authors.affiliation: Department of Ophthalmology, Federal University of São Paulo, São Paulo, Brazil. silvia.helenatavareslorena@yahoo.com.br
authors.forename: Silvia Helena Tavares
authors.initials: SH
authors.lastname: Lorena
authors.forename: João Amaro Ferrari
authors.initials: JA
authors.lastname: Silva
authors.forename: Marinho Jorge
authors.initials: MJ
authors.lastname: Scarpi
mesh_terms: D000367:Age Factors; D003608:Dacryocystorhinostomy; D005260:Female; D005865:Gestational Age; D006801:Humans; D015994:Incidence; D007223:Infant; D007231:Infant, Newborn; D007234:Infant, Premature; D007767:Lacrimal Duct Obstruction / Q000151:congenital* / Q000453:epidemiology*; D008297:Male; D009301:Nasolacrimal Duct / Q000002:abnormalities*; D012189:Retrospective Studies; D012737:Sex Factors; D047929:Term Birth