Nasolacrimal duct obstruction (NLDO) refers to blockage of the tear or nasolacrimal duct. Tear ducts are found on the corners of the lower and upper eyelids. Usually, the tears exit the eye through the small openings on the eyelids’ edges (puncta). The tears then drain into the nose via the nasolacrimal ducts. When the tear duct is obstructed, it prevents tears from draining properly. The condition is common in infants and can affect one or both eyes.
Some babies are born before these ducts have fully developed, thus have watery eyes. The disorder often goes away without treatment during the child’s first year of life. However, with tear duct blockage, the tears may flow backward and be discharged through the eye. This is serious because of the risk of infection, irritation, and a permanent blockage, referred to as nasolacrimal duct obstruction.
Also Known As
Causes & Risk Factors
Some children are born with the condition (congenital) where there is an abnormality with the duct. NLDO may also result from underdevelopment of the tear drainage system during pregnancy. Usually, there will be a membrane remaining over the nasolacrimal duct.
Other causes include trauma, where the tear drainage system is damaged through injury to the face. Blockage can also result from loose skin cells or small particles that lodge in the duct. Eye inflammation, chronic infection, and a tumor in the nose or surrounding structures may cause obstruction. Other causes include certain cancer treatments, aging, eye drops, and some inflammatory conditions.
Signs & Symptoms
Signs and symptoms include:
- Blurry vision
- Eyelid crusting
- Painful swelling around the eye’s corner
- Erythema and periocular skin breakdown in more severe cases
- Excessive watering where tears well up on the eye’s surface and run down the eyelids, eyelashes, and cheeks
- Red and swollen eyelids with greenish-yellowish pus or mucus discharge. A severe infection can result since the bacteria is not being flashed down
The disorder can be diagnosed through the following:
- A complete eye examination
- Patient history of tearing and discharge
- Imaging tests such as X-ray, CT scan, or MRI can provide pictures which tell the cause and position of the blockage
- Measurement of intraocular pressure to rule out conditions like childhood glaucoma, which may be confused with NLDO
- Clinical examination for signs and symptoms. The most common symptoms for NLDO is discharge and excessive tearing in infants. The doctor also checks for any structural disorders for obstruction caused by nasal passages
- Other conditions such as epiblepharon, conjunctivitis, corneal infection, and primary corneal disorders may be confused with NLDO. The ophthalmologist will do a physical examination and other tests to rule these out
- Tests to determine if the tear duct is blocked. One way is through the tear drainage test, where a drop of a special dye is placed on each eye's surface. The test is positive when most of the dye remains on the eye's surface five minutes later. Irrigation and probing is another test where the doctor flushes a saline solution through the tear drainage system. S/he inserts a probe (thin, straight instrument) into the drainage holes to determine how well the system is draining. Probing sometimes treats the condition
Treatment is aimed at unblocking the obstruction and allowing the proper functioning of the drainage system. Infants presenting with mild symptoms only need observation or conservative measures. In most cases, the obstruction goes away on its own without treatment before the child reaches ten months of life. NLDO caused by injury may require a wait-and-see approach because when the swelling goes down, NLDO may resolve. Sometimes the condition that caused the blockage, such as tumors, is treated first because it may resolve NLDO. Persistent NLDO requires treatment.
Topical antibiotic eye ointment or drops are used to treat the infection. Long-term use of antibiotics is discouraged because they do not open the blocked tear ducts. Symptoms recur once the antibiotics are discontinued.
Nasolacrimal duct probing is used when it is clear the disorder will not resolve on its own. This is usually when a child is older than ten months old. Surgeons may decide to use a single probe or a series of larger probes. Probes with larger diameters are more likely to widen the tear duct system and remove the membranes obstructing the ducts. Sometimes the surgeon may add a stent to prevent a recurrence of NLDO.
The surgeon can use local anesthesia and perform the procedure on an infant less than six months old who is awake. The child will recover quicker, and general anesthesia is avoided. Some ophthalmologists prefer to wait until the infant is older and perform surgery using general anesthesia.
Balloon catheter dilation is used when other treatment options fail or when the condition recurs. The surgeon passes a catheter containing a deflated balloon through the blocked tear duct and inflates and deflates the balloon a couple of times to open the blocked duct.
Intubation or stenting is performed where a thin tube is passed through the puncta, tear drainage system, and into the nose. After three months, the tube is removed. The patient uses eye drops and a nasal decongestant spray to reduce inflammation and prevent infection.
Parents or caregivers can perform a tear duct massage at home to open the obstructed duct. Using the index finger, the caregiver applies firm pressure over the lacrimal sac. The pressure enables the tears and mucus to flow back through the puncta. This action prevents superinfection in the tear sac and may open the obstructing membranes at the nose’s opening. A wet, warm washcloth can also be used on the eye several times a day to help with fluid drainage.
Prognosis & Long-Term Outlook
The surgical procedures to treat NLDO are often successful, especially when a stent is added. Sometimes repeat procedures may be required if the tear duct remains closed. A rare complication may arise where a red, painful, swollen nodule (dacryocele) appears over the duct accompanied by a discharge. This is a medical emergency and may need admission to hospital for intravenous administration of antibiotics. The stents used during surgery may also cause inflammation, requiring treatment.
Prevention & Follow Up
The infant will be followed up regularly until the blocked tear is completely open.