Congenital nasolacrimal obstruction

Congenital nasolacrimal obstruction is a failure of effective tear drainage present early in life. The eye surface may produce an appropriate volume of tears, but fluid cannot pass freely into the nose and instead pools at the lid margin or spills onto the cheek. A small amount of mucus may repeatedly stick the eyelashes together. The commonest anatomical explanation is a residual membrane near the distal duct opening, although abnormalities of the puncta, canaliculi or the wider drainage pathway can produce a similar history.

The timing helps distinguish congenital drainage delay from acquired disease. Parents often describe watering or crusting from the first weeks of life, sometimes affecting both eyes unevenly. Symptoms may fluctuate with a cold or nasal congestion. Fluctuation does not mean that repeated new infections have occurred, and yellowish material alone does not prove an invasive bacterial infection. The distinction rests on the whole examination, including the conjunctiva, cornea, medial canthus and the child's general condition.

Before offering reassurance, consider whether increased tear production is a response to ocular pain. An infant with corneal oedema from glaucoma may have abundant tears, strong light aversion and tightly closed eyelids. Corneal enlargement or cloudiness is incompatible with assuming simple drainage obstruction. Likewise, a neonatal red conjunctiva with heavy discharge demands assessment for ophthalmia neonatorum, even if a blocked duct was previously diagnosed. The drainage diagnosis should remain open to revision when the pattern changes.

Conservative care is appropriate for a well infant whose history and examination are reassuring. Explain the expected improvement during the first year and demonstrate cleaning that removes crusts without abrading the lid skin or cornea. A clinician can teach downward pressure over the lacrimal sac, using a clean fingertip beside the nose, while avoiding pressure on the globe. The aim is to increase pressure within the drainage passage; repeated rubbing across the eye itself does not achieve this. Families should stop and seek review if a painful swelling develops.

A short course of a clinician-selected topical antibiotic may be useful when discharge is sufficiently troublesome or there is a diagnosed superficial infection. It is not a preventive treatment for every watery eye and repeated courses do not correct the obstruction. Prescribing for an infant requires an age-appropriate product, indication and review plan. Systemic infection, dacryocystitis and neonatal gonococcal or chlamydial infection have different treatment requirements; a familiar bottle of conjunctivitis drops is not an adequate substitute.

Referral timing is a clinical pathway decision rather than proof that a duct must be operated on at a particular birthday. The Moorfields GP pathway uses non-urgent referral for uncomplicated symptoms persisting beyond 12 months, while allowing urgent assessment for serious findings. Earlier specialist advice is appropriate for severe symptoms, recurrent infections, skin damage, unusual anatomy or uncertainty. The referral should describe the actual examination and burden of symptoms so the specialist can decide whether observation remains reasonable.

Persistent obstruction can be treated by probing the drainage passage, sometimes with irrigation, intubation or balloon techniques when the anatomy or previous response warrants them. The ophthalmologist selects the procedure and anaesthetic approach for the child; families should not attempt syringing or instrumentation at home. Failed probing does not automatically imply a dangerous diagnosis, but it prompts reassessment of the obstruction and the options. Even after successful drainage treatment, unrelated refractive error or squint still requires its own evaluation.