Congenital Nasolacrimal Duct Obstruction

Congenital nasolacrimal duct obstruction (CNLDO) results from failure of canalisation of the distal nasolacrimal duct, usually a persistent membrane at the valve of Hasner.

• Affects about 5 to 20 percent of newborns, bilateral in about one third.
• Spontaneous resolution occurs in about 90 percent by 12 months of age.
• Risk factors: Down syndrome, craniofacial anomalies (Pierre Robin, craniosynostosis, hemifacial microsomia), and congenital punctal atresia. Complicated forms include dacryocystocele (amniotic fluid distension of the sac, bluish swelling below the medial canthus) which can become infected.

• Persistent watering (epiphora) and sticky mucoid or mucopurulent discharge from the first weeks of life, typically noted by 3 to 4 weeks, with matted lashes on waking.
• Quiet, white eye without conjunctival injection or photophobia (unlike congenital glaucoma, infective conjunctivitis).
• Regurgitation of mucus on pressing the lacrimal sac.
• Recurrent acute dacryocystitis: red, tender swelling at medial canthus with fever.
• Dacryocystocele: bluish cystic mass at birth, may cause respiratory distress by intranasal extension in bilateral cases (neonates are obligate nasal breathers).

• Clinical history and examination. Fluorescein dye disappearance test: persistence of dye after 5 minutes in the tear meniscus indicates obstruction.
• Exclude other causes of watering: congenital glaucoma (corneal haze, enlarged cornea, photophobia), punctal agenesis, congenital eversion, corneal abrasion, conjunctivitis, blepharitis, and trichiasis.
• Intranasal examination for dacryocystocele with endoscopy.
• Lacrimal probing under anaesthesia is diagnostic and therapeutic. Imaging (dacryocystography, CT) is reserved for complicated or craniofacial cases.

• Observation with lacrimal sac massage (Crigler): press over the sac and stroke downward 2 to 3 times, 3 to 5 times daily, with warm compress and cleaning of discharge.
• Topical antibiotic only for acute mucopurulent discharge: for example erythromycin 0.5 percent ointment or chloramphenicol 0.5 percent drops four times daily for 5 to 7 days.
• Acute dacryocystitis: systemic antibiotics (amoxicillin clavulanate 25 to 45 mg/kg/day of amoxicillin in 2 to 3 divided doses, or cefazolin intravenously 50 mg/kg/day in 3 divided doses), warm compress, and delayed probing after the infection settles.
• Dacryocystocele: massage, warm compresses, prophylactic antibiotics; urgent probing if infected, large, or causing respiratory compromise, with intranasal marsupialisation.
• Probing at 12 months of age if still symptomatic (success about 80 to 95 percent): office probing with topical anaesthetic is possible at 6 to 12 months; earlier probing is justified for recurrent dacryocystitis, dacryocystocele, or family preference.
• Failed probing: repeat probing with balloon catheter dilation, inferior turbinate infracture, or silicone intubation (left in place 3 to 6 months).
• Persistent obstruction after 2 attempts: dacryocystorhinostomy (external or endoscopic) at 3 to 4 years or later.
• Bypass for canalicular agenesis: conjunctivodacryocystorhinostomy with a Lester Jones tube.