A constantly watery eye is not just an inconvenience. In babies it is almost always treatable without surgery. In adults it deserves proper investigation. Either way, the solution exists.

The nasolacrimal duct is the channel that drains tears from the eye into the nose, which is why your nose runs when you cry. When this channel is blocked or narrowed, tears can’t drain properly and overflow onto the cheek. This is nasolacrimal duct obstruction (NLDO). It is one of the most common eye conditions in newborns, affecting around 6 percent of infants. It also occurs in adults, usually from ageing, chronic inflammation, or anatomical narrowing. Management differs considerably between the two age groups, but in both cases the condition is very treatable.

How the Tear Drainage System Works

Tears are produced by the lacrimal gland and spread across the eye surface with each blink. They drain away through two tiny openings called puncta, one on each eyelid at the inner corner. From there, tears flow through narrow channels called canaliculi into the lacrimal sac, which sits in a small bony hollow at the inner corner of the orbit. The lacrimal sac connects to the nasolacrimal duct, which runs down through the bone of the face and opens into the nose beneath the inferior turbinate.

When any part of this system is blocked, tears overflow onto the lower eyelid. The lacrimal sac can also become a reservoir for bacteria, leading to recurrent infections and a sticky mucous discharge. In some cases the lacrimal sac becomes acutely infected (dacryocystitis), causing a painful red swelling at the inner corner that needs antibiotic treatment.

Congenital NLDO: In Babies and Infants

Why it happens

In the developing fetus, the nasolacrimal duct forms as a solid cord of cells that gradually hollows out. At the lower end, a thin membrane called the valve of Hasner normally opens just before or shortly after birth. In around 6 percent of newborns, this membrane remains intact, blocking the lower end of the duct. The baby’s eye looks normal but produces a persistent watery discharge, often with mucous crusting at the inner corner, particularly after sleep.

Most cases resolve on their own

The majority of congenital NLDO resolves spontaneously as the membrane naturally opens during the first year of life. Around 90 percent of affected infants clear up by 12 months without any surgical intervention. That figure is worth repeating, because a lot of parents arrive expecting to hear the word surgery. The parents’ role during this period is to keep the eye clean and to perform Crigler massage, which helps accelerate resolution and reduces the frequency of discharge and infection.

Crigler massage

Crigler massage applies pressure to the lacrimal sac to increase hydrostatic pressure within the duct and encourage the obstructing membrane to open. It is performed several times a day and takes only a few seconds.

When probing is needed

If the obstruction hasn’t resolved by 12 months, or earlier if recurrent infections are causing significant problems, probing and syringing under general anaesthetic is recommended. A fine metal probe is passed through the punctum and canaliculus into the lacrimal sac and down the nasolacrimal duct, opening the obstructing membrane. The duct is then syringed with saline to confirm it is patent. The procedure takes a few minutes and is successful in around 90 percent of cases after a single treatment. A small proportion of children require a second procedure or placement of a temporary silicone stent.

If you would like to learn more, the American Association for Pediatric Ophthalmology and Strabismus page on nasolacrimal duct obstruction offers a clear overview of symptoms, causes, diagnosis, and treatment.

Acquired NLDO: In Adults

Why it happens in adults

In adults, NLDO is usually acquired rather than congenital. The most common cause is idiopathic fibrosis and narrowing of the duct, a gradual process associated with ageing and chronic low-grade inflammation. Other causes include chronic sinusitis, previous nasal or facial surgery, inflammatory conditions such as uveitis or sarcoidosis, certain medications (particularly long-term eye drops), and less commonly tumours of the lacrimal drainage system.

Symptoms in adults

Persistent epiphora: tears running down the cheek. Worse in cold or windy conditions, when reading, and when driving. Some patients develop recurrent episodes of acute dacryocystitis, presenting as a red, swollen, tender lump at the inner corner. Chronic low-grade dacryocystitis causes a persistent mucous discharge that can be expressed from the punctum by pressing over the lacrimal sac. Untreated, this can occasionally progress to a mucocele or a fistula.

Investigation

The ophthalmologist first examines the eyelids and puncta to exclude other causes of watering such as dry eye disease, eyelid malposition (ectropion), or punctal stenosis. Syringing of the lacrimal system in the clinic, where saline is gently injected through the punctum, confirms the presence and level of obstruction. Imaging studies may be used to characterise the obstruction further before planning surgery.

Treatment in Adults

Dacryocystorhinostomy (DCR)

DCR is the standard surgical treatment for acquired NLDO in adults. The procedure creates a new opening directly between the lacrimal sac and the nasal cavity, bypassing the blocked nasolacrimal duct entirely. It can be performed externally, through a small skin incision at the side of the nose, or endoscopically, through the nose without any external incision. Both approaches have success rates of 90 to 95 percent. A thin silicone tube is usually placed through the new opening during surgery and removed in the clinic a few months later once the new channel has healed.

External DCR leaves a small scar at the side of the nose that typically fades to barely visible within a few months. Endonasal DCR avoids any external incision and allows simultaneous treatment of nasal pathology contributing to the obstruction.

Balloon dacryoplasty and syringing

For partial obstructions, balloon dacryoplasty (a tiny inflatable balloon catheter passed through the duct to dilate it) and simple syringing under local anaesthetic can provide relief in selected cases. These approaches are less definitive than DCR and have lower long-term success rates, but they are useful in patients who are not surgical candidates or who prefer a less invasive first step.