Nasolacrimal Duct Obstruction

Nasolacrimal duct obstruction (NLDO) is blockage of tear drainage between the lacrimal sac and the nose, causing epiphora and recurrent infection.

• Congenital NLDO affects 5 to 6 percent of newborns, nearly always from a persistent membrane at the valve of Hasner at the distal duct. About 90 percent resolve spontaneously by 12 months.
• Acquired NLDO: primary involutional (idiopathic inflammation and fibrosis of the duct lining, older women), and secondary (dacryocystitis, trauma, sinus or nasal surgery, sinusitis, nasal tumours, granulomatous disease, radioiodine, chemotherapy such as docetaxel, and topical drugs).
• Complex congenital obstruction: Down syndrome, craniofacial anomalies, and absent punctum or canalicular atresia.
• Lacrimal sac stasis predisposes to dacryocystitis.

• Constant tearing (epiphora), mucous or mucopurulent discharge crusting on the lashes (mattering), and wet cheeks, worse outdoors and in the cold.
• Congenital: onset in the first weeks, with intermittent discharge and a quiet white eye (no conjunctival injection unless infected), lid margin crusting, and positive reflux on pressure over the sac.
• Acquired: epiphora, recurrent sticky eye or conjunctivitis, and recurrent sac swelling (mucocele) or infection.
• Red flags: eye redness with photophobia and corneal haze (congenital glaucoma, which also causes tearing), purulent swelling at the medial canthus (acute dacryocystitis), and bloody discharge or a mass (tumour).

• Fluorescein dye disappearance test: persistence of dye in the tear film after 5 minutes (or in the infant after 5 to 10 minutes) with absent dye in the nose.
• Lacrimal irrigation (syringing): reflux through the opposite punctum shows complete NLDO (adults), whereas reflux through the same punctum with a hard stop indicates canalicular obstruction; a soft stop localises the block to the sac or duct.
• Probing with Bowman probes (in suspected canalicular obstruction).
• Imaging in complex or atypical cases: CT dacryocystography, dacryoscintigraphy, nasal endoscopy for obstruction at the valve of Hasner or the nose, and sinus CT; MRI when tumour is suspected.
• Exclude other causes of tearing: dry eye (reflex tearing), blepharitis, allergic conjunctivitis, trichiasis, punctal stenosis, corneal disease, and congenital glaucoma (examine corneal diameter and intraocular pressure).

• Congenital NLDO:
  • Observation with lacrimal sac massage (Crigler): finger pressure over the lacrimal sac and downward stroking, 5 to 10 strokes two to three times daily, to promote rupture of the membrane. Clean the lids with warm water.
  • Topical antibiotic only when mucopurulent discharge is present: erythromycin 0.5 percent ointment or chloramphenicol 0.5 percent drops 3 to 4 times daily for 5 to 7 days (not continuously).
  • If persistent at 12 months (or earlier if recurrent dacryocystitis, dacryocystocele, or complex), probing of the nasolacrimal duct under brief general anaesthesia or sedation, with success of 80 to 90 percent. Office probing without anaesthesia is done in some centres in infants under 12 months.
  • Failed probing: repeat probing with balloon dacryoplasty or silicone tube intubation for 3 to 6 months, inferior turbinate infracture, then dacryocystorhinostomy after age 2 to 4 years if unsuccessful.
• Acquired NLDO:
  • Dacryocystorhinostomy (external with a skin incision, endoscopic transnasal, or transcanalicular laser) creating an anastomosis between sac and nasal mucosa, with silicone tube intubation for 3 to 6 months and, in recurrences, adjunctive mitomycin C 0.2 mg/mL for 2 to 5 minutes. Success rate is 90 to 95 percent.
  • Canalicular obstruction or common canalicular block: conjunctivodacryocystorhinostomy with a glass Jones tube.
  • Punctal stenosis: punctoplasty (one snip or three snip) with or without silicone stents.
  • Dacryocystectomy in patients unfit for surgery.
  • Treat secondary causes (sinusitis, granulomatous disease), and review drugs.
• Perioperative and postoperative: prophylactic antibiotics (cefalexin 500 mg twice daily for 5 days) in some centres, nasal decongestant (oxymetazoline 0.05 percent spray twice daily for 3 days) and saline irrigation, topical steroid antibiotic drops (dexamethasone 0.1 percent with tobramycin 0.3 percent four times daily for 2 weeks), and avoidance of nose blowing for 2 weeks.
• Follow up with syringing at 1 and 3 months; remove silicone tubes at 3 to 6 months.
• Complications: dacryocystitis, orbital cellulitis, recurrent conjunctivitis, surgical failure from scarring, bleeding, and cutaneous scar.