Possible causes of congenital obstruction to the nasolacrimal duct:
(1) stenosis of the duct
(2) atresia
(3) agenesis
(4) duplication
(5) membranous obstruction at the distal end
(6) congenital dacrocystitis
Clinical features:
(1) watery discharge from the eye down the cheek (tearing, epiphora), usually unilateral but sometimes bilateral
(2) onset of discharge within first few weeks after delivery
(3) presence of a tear meniscus at the medial canthus
(4) mucocele at the medial canthus
Occasional findings:
(1) some patients develop an intermittent mucopurulent discharge
(2) some patients develop intermittent conjunctivitis
(3) crusting on lashes may be present
Notably absent:
(1) signs of active infection
(2) photophobia
(3) signs of irritation
Spontaneous resolution suggests a membranous obstruction that has perforated.
