Blocked Tear Duct

Definition/diagnostic criteria A blocked tear duct (also known as nasolacrimal duct obstruction) is a condition characterised by obstruction of the tear drainage system, leading to epiphora (excessive tearing). In adults, this can result from infection, inflammation, injury or tumours. In neonates, it often occurs due to a failure of the membranous covering of the nasolacrimal duct to open after birth.

Epidemiology The condition is common in neonates, affecting up to 20% of newborns, usually resolving spontaneously by 12 months. The prevalence in the older population is unclear, but it is commonly seen in general practice and by opticians.

Diagnosis
Clinical features: Patients typically present with persistent tearing and may also have mucoid or purulent discharge, recurrent conjunctivitis or acute dacryocystitis. Swelling near the inner corner of the eye may be seen.

Investigations: The diagnosis is usually clinical. Primary investigations when required include the regurgitation test on pressure over the lacrimal sac, and the fluorescein dye disappearance test. Advanced imaging like dacryocystography or CT dacryocystography is used in atypical or complicated cases.

Typical abnormalities found include delayed or absent tear drainage on dye test and dilation of the lacrimal sac or nasolacrimal duct on imaging.

Treatment Treatment depends on the cause and severity of the blockage.

• In neonates, first-line treatment includes conservative management such as lacrimal sac massage. If symptoms persist beyond 12 months, or in severe cases, probing of the nasolacrimal duct is recommended.
• In adults, initial management includes addressing any underlying infection with topical antibiotics. In cases of chronic blockage, dacryocystorhinostomy (DCR), a surgical procedure to create a new tear drainage route, is considered the standard treatment.
• For acute dacryocystitis, systemic antibiotics are indicated, and in severe cases, surgical intervention may be required.

Prognosis The prognosis for blocked tear ducts is generally good. In neonates, spontaneous resolution is common, with up to 90% resolving by their first birthday. Adult patients who undergo DCR surgery have high success rates, with symptom resolution in approximately 85-90% of cases.