Lacrimal Duct Obstruction
Lacrimal Duct Obstruction
A lacrimal duct obstruction is blockage of the tear duct, the thin channel that normally drains tears from the surface of the eye.
The lacrimal glands, located above each eyeball, produce tears. The tears flow over the eye, then drain through the nasolacrimal ducts. A tiny hole at the inner edge of each eyelid marks the opening of the ducts, which lead to the lacrimal sacs located on the side of the nose. The tears pass from the sacs into the nasolacrimal ducts and then into the nose.
When a tear duct becomes obstructed, tears may spill over the eyelids and run down the face. Stagnant tears within the system can become infected, leading to recurrent red eyes and infections. Excessive tearing can also produce secondary skin changes on the lower eyelids.
Causes and symptoms
An obstructed lacrimal tear duct can result in inflammation and infection of the lacrimal sac. The area beneath the eyes next to the nose can become red, inflamed, and sensitive to the touch. The area usually is swollen, and there may be a mucous discharge from the opening of the nasal corner of the eye. Common complaints include itching, irritation, burning, redness, foreign body sensation, and tearing.
Children frequently have a congenital lacrimal duct obstruction. Six to ten percent of all children are born before their tear ducts are open.
In adults, a common cause of lacrimal duct obstruction is involution, which is progressive degeneration occurring naturally with advancing age, resulting in shrivelling of organs or tissues. Other causes include eyelid disorders, infections by bacteria, viruses, fungi, and parasites, inflammations, the use of eye drops or excessive nasal spray, systemic chemotherapy, trauma from previous surgeries, injury to the bone at the side of the nose, foreign bodies, sinus disease, nasal polyps, and malignant or benign tumors.
If the primary symptom is excessive tearing, the first step is for the health care professional to determine if the overflow of tears is due to an increase in tear production or a decrease in tear drainage. Causes of increased tear production may include trichiasis, a disease in which the eyelashes produce constant irritation, and eyelid malpositions and diseases. If abnormal tear production is ruled out, then obstructions in tear drainage is the most likely cause of the excessive tearing. Additional observations of swollen lacrimal sac area and purulent eye discharge indicate that there may be a lacrimal duct infection present. To further define the diagnosis, the lacrimal discharge may be cultured to determine possible infective agents, while various imaging techniques may be used to detect the type of obstruction. Dye tracer tests are also used to test for blockages.
Lacrimal duct obstructions in children often resolve spontaneously, with 95% showing resolution before the child is one year old. Daily massaging of the lacrimal sac may help open the blockage. A topical antibiotic ointment may be applied if infection is present. If the blockage is not resolved after several weeks to months of this therapy, a physician may attempt forceful irrigation. Surgical probing to open up the duct under general anesthesia is a last resort, after a year or so of less invasive treatments.
In adults, conservative treatments are usually recommended. The infected or inflamed area may be massaged, with warm compresses applied to provide relief and speed the healing process. The health care provider may also massage or irrigate the infected area. Topical antibiotic ointments and oral antibiotics may also be used reduce infection. The use of analgesics such as aspirin may be recommended to control discomfort and reduce swelling. Severe cases may require surgical intervention to prevent future recurrences. Surgical approaches include insertion of a probe or catheter to remove an obstruction or creation of an artificial duct to bypass the obstruction.
If more conservative approaches fail to clear the obstruction, surgical procedures are available, with success rates greater than 90%.
In many cases, the cause of a lacrimal duct obstruction is not known. However, in some cases, lacrimal duct obstruction may be caused by smoking and abuse of nasal sprays.
Camara, Jorge G., and Alfonso U. Bengzon. "Nasolacrimal Duct Obstruction." eMedicine Journal August 24, 2000. 〈http://www.emedicine.com/OPH/topic465.htm〉.
Lacrimal duct— A short canal leading from a small orifice at the medial angle of each eyelid to the lacrimal sac.
Lacrimal gland— An almond-shaped gland that secretes tears.
Lacrimal sac— The dilated upper end of the nasolacrimal duct in which the lacrimal ducts empty.
Nasolacrimal duct— A channel that transmits tears from the lacrimal sac to the nose.
Purulent— Consisting of or containing pus
Tear— A drop of the clear, salty fluid secreted by the lachrimal gland.
Trichiasis— A disease of the eye, in which the eyelashes, being turned in upon the eyeball, produce constant irritation by the motion of the lids.
Dacryocystitis is an inflammation of the tear sac (lacrimal sac) at the inner corner of the eye.
Tears drain into little openings (puncta) in the inner corners of the eyelids. From there, the tears travel through little tube-like structures (canaliculi) to the lacrimal sac. The nasolacrimal ducts then take the tears from the lacrimal sac to the nose. That's why people need to blow their nose when they cry a lot.
Dacryocystitis is usually caused by a blockage of the nasolacrimal duct, which allows fluid to drain into the nasal passages. When the lacrimal sac does not drain, bacteria can grow in the trapped fluid. This condition is most common in infants and people over 40 years old.
Causes and symptoms
In newborn infants, the nasolacrimal duct may fail to form an opening-a condition called dacryostenosis. The cause of dacryocystitis in adults is usually associated with inflammation and infection in the nasal region. Dacryocystitis can be acute, having a sudden onset, or it can be chronic, with symptoms occurring over the course of weeks or months. Symptoms of acute dacryocystitis can include pain, redness, tearing, and swelling at the inner corner of the eye by the nose. In chronic dacryocystitis, the eye area may be swollen, watery or teary, and, when pressure is applied to the area, there may be a discharge of pus or mucus through the punctum.
Dacryocystitis usually occurs in only one eye. As mentioned, the symptoms can range from watery eyes, pain, swelling, and redness to a discharge of pus when pressure is applied to the area between the bridge of the nose and the inner eyelids. A sample of the pus may be collected on a swab or in a tube for laboratory analysis. The type of antibiotic and treatment may depend on which bacteria is present. In the acute form, a blood test may reveal an elevated white blood cell (WBC) count; with a chronic infection, the WBC count is usually normal. To identify the exact location of the blockage, an x ray can be taken after a dye is injected into the duct in a procedure called dacryocystography.
A warm compress applied to the area can help relieve pain and promote drainage. Topical and oral antibiotics may be prescribed if an infection is present. Intravenous antibiotics may be needed if the infection is severe. In some cases, a tiny tube (cannula) is inserted into the tear duct which is then flushed with a sterile salt water solution (sterile saline). If other treatments fail to clear up the symptoms, surgery (dacryocystorhinostomy) to drain the lacrimal sac into the nasal cavity can be performed. In extreme cases, the lacrimal sac will be removed completely.
In infants, gentle massage of the lacrimal sac four times daily for up to nine months can drain the sac and sometimes clear a blockage. As the infant grows, the duct may open by itself. If the duct does not open, it may need to be dilated with a minor surgical procedure.
Treatment of dacryocystitis with antibiotics is usually successful in clearing the infection that is present. If there is a permanent blockage that prevents drainage, infection may recur and surgery may be required to open the duct. If left untreated, the infected sac can rupture, forming an open, draining sore.
There are no specific recommendations for the prevention of dacryocystitis, however, good hygiene may decrease the chances of infection.
Gorbach, Sherwood L., John G. Bartlett, and Neil R. Blacklow, editors. "Dacryocystitis." In Infectious Diseases. 2nd ed. Philadelphia: W. B. Saunders Co., 1998.
Canaliculi— Also known as lacrimal ducts, these tube-like structures carry the tears from the eyes to the lacrimal sac.
Cannula— A narrow tube that can be inserted into a duct.
Dacryocystography— An x ray of the tear duct after injection of a dye that is used to help locate a blockage in the duct.
Dacryocystorhinostomy— A surgical procedure to drain the tear sac into the nasal passage.
Dacryostenosis— Obstruction or narrowing of the nasolacrimal duct. May be present at birth.
Nasoacrimal duct— The tube that carries the tears from the lacrimal sac to the nose.
Punctum— Tiny opening at the inner corners of the upper and lower lids. The area for the beginning of tear drainage.