Our eyes are constantly making a protective film of tears to bathe the eyeball. Simple in appearance, tears have a marvelously complex structure. The tear film is composed of three layers. The thin outer layer, produced by the inside of the eyelids, is an oily film. The largest part of the tear structure is a middle layer of salty water, produced in the lacrimal gland. The innermost layer, produced by the conjunctiva on the front of the eye, is composed mostly of mucus. This wonderfully designed film is ideal to protect, cleanse, and lubricate the eye.
Tears normally drain though a pinpoint opening at the inside corner of the eye. They then flow through the nasolacrimal duct into the nose.
In many babies, the nasolacrimal duct is not fully developed at the time of birth. Signs of this usually appear in the first weeks of life. The duct may be plugged by a membrane left from birth, or by swelling or mucus. This is called nasolacrimal duct obstruction (NLDO) or a blocked tear duct. A child who has an unusually narrow duct has dacrostenosis.
This condition occurs in infants and is quite common.
The tears back up, causing wetness or pooling. As the watery layer evaporates, a soft mucoid discharge accumulates, which can then dry and become crusty.
Children with blocked tear ducts are also more prone to conjunctivitis.
Blocked tear ducts usually disappear on their own by the time a child is a year old.
The diagnosis is based on the history and physical exam.
The primary treatment is gentle cleansing of the lids with a warm wet washcloth. Use a clean portion of the washcloth with each pass. This may be accompanied by a regimen of gentle nasolacrimal duct massage, usually 2 or 3 times a day. With a clean finger, simply rub the area between the inside corner of the eye and the bridge of the nose. Occasionally symptoms persist beyond one year of age. If they do, probing of the duct by a pediatric ophthalmologist is indicated.
Sometimes eye drops are needed if an infection is beginning.
Gentle nasolacrimal duct massage can prevent some episodes of obstruction in a baby who is prone.
Dacrostenosis, Nasolacrimal duct obstruction, NLDO