Cause
The most common cause of a
blocked tear duct is the failure of the thin tissue,
or membrane, that covers the tear duct (lacrimal duct) to open normally into
the nasal passage shortly after birth. This disrupts the usual
drainage system for tears.
Symptoms usually are not noticed if the blockage resolves on its
own before a baby starts producing
tears. Normally, tears start forming within the first
few days to weeks following birth.
Less common causes of blocked tear ducts in babies can
include:
- Infection in the tubes that drain tears from
the eyes to the nose (dacryocystitis).
- Blockage of the tear duct at
both ends (dacryocystocele).
- Abnormal growth of the
nasal bone that puts pressure on a tear duct, closing it off.
-
Closed or undeveloped openings in the corners of the eyes (puncta) where tears
normally drain into the tear ducts.
Blocked tear ducts in adults
The
cause of blocked tear ducts in adults is usually
related to another disorder or an injury. For example, a blocked tear duct may
result from a thickening of the tear duct lining, abnormal tissue or structures
in the nose, or complications of surgery on or around the nose. These types of
problems are more likely to occur after age 60 than in earlier
adulthood.