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Congenital Nasolacrimal Duct Obstruction

 Congenital NasoLacrimal Duct Obstruction
Lacrimal Apparatus comprises of main Lacrimal gland, Accessory Lacrimal gland, and  Lacrimal passages which include puncta, canaliculi, lacrimal sac and Nasolacrimal duct.

Congenital  NLDO:

Congenital Nasolacrimal duct obstruction occurs in approximately 30% of normal newborn
infants. The blockage occurs most commonly at the valve of Hasner, at the distal end of the Naso lacrimal duct. Both male and femlae are equally affected. The blockage can be unilateral or bilateral.  The rate of spontaneous resolution is estimated to be 90% within the first year of life. Obstruction of the nasolacrimal duct leads to the excess overflow of tears called Epiphora. In our country Nepal, the use of mascara(Gajal) for beauty, pouring mothers milk or Mustard oli in the eye if the child has any ocular problem, has become the leading cause of blockage in Nasolacrimal duct of newborn infants.
Epiphora

Causes:
Presence of  Epithelial debris.
Membranous occlusion at its upper upper end near lacrimal sac.
Membranous occlusion at "valve of  Hasner".
Stenosis of the duct.
Maldevelopment of punctum and canaliculi.

Note: In our country Nepal,  it is widely believed that frequent watering is due to cold weather too. Sometimes, watering do occur in winter but not all epiphora are due to cold weather.

History:
Baby tears due to duct occlusionParents come with the complain of watering in one or both the eyes even when the child is not crying .watering may be associated with discharge or without discharge.

Signs:

No conjunctival congestions.Most become symptomatic during the first month of life. Congenital NLDO presents as chronic tearing of one or both eyes may or not may not be  associated with mucopurulent discharge. The involved side has an increased tear lake meniscus. The eyelashes are usually wet and matted. The skin of the lower eyelid may appear erythematous in more severe cases.
Diagnostic  procedure:
A fluorescein dye disappearance test can be helpful in confirming the diagnosis of nasolacrimal duct obstruction.  A drop of fluorescein is instilled into the eyes and disappearance of dye from the tear film after 5 minutes is observed. Retained dye in a thickened tear strip is diagnostic of an obstruction. The test is most useful if the disease is unilateral and the findings of the affected eye can be compared to those of the normal eye.

Treatment:
  • Conservative treatment: In most cases, simple massaging of the ducts may be enough because of the high rate of spontaneous resolution. Parents should be advised to apply gentle pressure with their finger over the common canaliculus, stroking downwards firmly to raise pressure in the lacrimal sac causing the opening of the valve.Parents should perform this massage for at least four times per day(10 counts each time).Parents should be advised to keep their child’s eye free of discharge.
Use topical antibiotics for any episodes of associated conjunctivitis (i.e. red conjunctiva as opposed to simple discharge).
In infants with nasolacrimal duct obstruction (NLDO) who are aged between 6 and 10 months, non-surgical management will resolve symptoms within six months, in over half of cases.
  • Lacrimal syringing with normal saline and antibiotic solution.
  • Probing of NLD with Bowman’s probe.
  • Intubations with silicone tube may be performed if repeated probings are failed.
  • Surgical : Dacryocystorhinostomy
About the author: Dipsika Aryal is an Ophthalmic Assistant working in Patan Academy of Health Science, Nepal

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