By Dr. Charles J. Bock

Nasolacrimal Duct Obstruction

About the nasolacrimal system

A nasolacrimal duct obstruction is a blockage of tear drainage that causes tearing and, in some cases, repeated infections of the eye. Like the rain gutters on your home, the nasolacrimal duct drains tears from the eye. The tears first enter through tiny holes in the eyelids, called puncta. There is one punctum on the upper lid and one on the lower lid of each eye. The puncta are located about ¼ inch from the inner corner of the eyelid. From here, the upper and lower portions merge and drain into a structure called the nasolacrimal sac. The nasolacrimal duct drains the tears from this sac into the nose. This is why your nose runs when you cry.

During prenatal development, the opening from the nasolacrimal duct into the nose sometimes does not form, and the opening remains covered by a thin piece of mucous membrane. In fact, this membrane is not fully open in many newborns; tear blockage is not noticed, however, because tear production is not yet normal. As tear production in the newborn develops, the membrane usually develops its opening.

In some children, tear production develops before the membrane opens. Because tears are unable to drain into the nose, they build up in the eye and often run down the face. The lack of tear flow also often allows infection to develop, resulting in a "goopy" eye. Sometimes this infection is present in the nasolacrimal sac, as well, and pressure on the inner corner of the eye results in accumulation of discharge on the surface of the eye.

The good news is that this situation will resolve on its own by six months of age in 90% of these children. Therefore, Dr. Bock usually does not recommend opening this duct in infants under six months of age. There are exceptions, however. Children who have this problem with infection in the first few days to weeks of life may have an abnormality, called a dacryocystocele, which requires prompt treatment. Additionally, children with repeated infections that are difficult to control with medication may benefit from early treatment.

Treatment of the Obstruction

Instead lieu of early surgery, Dr. Bock usually recommends regular nasolacrimal massage (described below) and use of a mild antibiotic eye drop as needed if an infection occurs. If the obstruction remains present at eight or nine months of age, it is then usually appropriate to consider treating the obstruction. The procedure, called a probing and irrigation, is performed in the operating room under general anesthesia, but intubation (placement of a breathing tube) is not usually needed. The procedure includes passing a series of thin wires into the nasolacrimal system to open the membrane, and then irrigating with fluid to be sure an opening has been created. Occasionally, abnormalities other than a simple blockage by a mucous membrane will be noted, and Dr. Bock will discuss these with you. For children nine to twelve months old, the procedure has a success rate of approximately 90%.

There is no need to rush into surgery if the child's parents wish to wait. It is true, however, that a blockage that exists at nine to twelve months of age is unlikely to resolve on its own, so most parents choose to proceed with surgery at this time.

If the initial probing and irrigation procedure is not successful, Dr. Bock will likely recommend a second procedure. There are some pediatric ophthalmologists who recommend a second probing and irrigation, and others who recommend placement of plastic tubes. Dr. Bock usually recommends the tubes, because these have a high rate of success (again, about 90%). The tubes are placed by inserting thin metal wires that are similar to the probes used in the first procedure, except that they are attached to flexible tubing. The wires are removed, and the tubes are tied to form a continuous loop. This loop of tubing is left in place for four to six months. The tubing can usually be removed quickly and painlessly in the office.

There was a time when it was recommended that all children over the age of 15 to 18 months needed to have tubes placed as a first procedure because many people believed that a simple probing and irrigation was not enough to open the ducts of these older toddlers. We now know that the success rate of a probing and irrigation, while a little less than 90%, is still very high, and so Dr. Bock recommends trying a probing and irrigation first, even in toddlers and young children.

When to call

Feel free to call our office 503-656-4221 at any time with any questions you have. If your child has been scheduled for a probing and irrigation and you think the problem has improved, please call and we'll see you right away. Similarly, if you think the problem is worse, or an infection is worsening despite treatment, we'll want to see you promptly.