What Causes a Blocked Tear Duct?

Tears are naturally produced in the lacrimal gland and have several functions: to continually self-lubricate the eyes, to clean and protect the eyes from infection and to express emotion or pain from injury. After tear production and movement over the cornea, tears will normally drain through two tiny holes on the inner corner of each eye and move down a small tube called the nasolacrimal duct into the nasal passage. However, some infants and adults have blocked tear ducts, which results in irritation and possibly infection of the eye.

Dacryostenosis

• Dacryostenosis, or congenital nasolacrimal duct obstruction, is a common cause of blocked tear ducts in newborns. This condition occurs when a membrane that covers the tear duct doesn't open before birth. Most times, the duct will open on its own within the first two months of life. If it doesn't open on its own, a doctor may have to perform a procedure to open the duct.

Craniofacial Abnormalities

• Babies born with certain diseases, like Down syndrome, may have abnormal growth of the nasal bone. This results in an additional pressure put upon the tear duct and the prevention of proper drainage through the nasal passageway. A blocked tear duct may be opened through massage of the area and antibiotic drops, but if the condition is not resolved by the first year of life, an ophthalmologist may open the duct.

Chronic Eye Infections & Inflammations

• Adults that experience chronic eye infections or persistent inflammation of the eye, nasolacrimal duct or nose may have a blocked tear duct as a result. Conjunctivitis and frequent sinus infections are two chronic conditions that can cause tear ducts to block. Doctors will usually treat the condition by caring for the underlying cause first.

Tumors, Cysts or Stones

• Tumors, cysts or stones that grow in the lacrimal gland or along the tear duct passageway can result in a partial or complete tear duct blockage. Blocked tear ducts that result from a tumor may not be treatable.

Facial Injury

• An injury to the face that causes bone damage near the tear duct can alter the usual flow of tears through the passageway. Surgery may be needed to correct the problem.

Topical Medications

• Though rare, long-term topical medications that adults use for such illnesses as glaucoma can cause a blocked tear duct. Sometimes people being treated for breast or lung cancer with a chemotherapy medication called docetaxel can have blocked tear ducts as a side effect. Doctors can usually treat the obstruction of the tear ducts when the condition is initiated by medication.