What Is Trachoma?
An infection caused by a species of chlamydia, trachoma is highly treatable and preventable, but it continues to be a major cause of blindness in developing countries. In its initial stages, trachoma is treated with oral or topical antibiotics, but in later stages, surgery may be necessary to prevent further vision loss.
Poverty, crowded living conditions, lack of clean water, and uncontrolled fly populations are all risk factors for this disease.
Trachoma is uncommon in the United States, but it is a public health problem in parts of South America, Africa, Asia, and Australia, especially in rural areas with limited access to clean water and sanitation.
Children between the age of 4 and 6 are most often affected; in some countries, as many as 40 percent of all children have contracted trachoma.
Women are at higher risk than men, probably because women often care for small children, and transmission of trachoma from child to mother is common. In most cases, both eyes are infected.
Even though it is highly treatable, trachoma is a major cause of blindness and vision loss in the developing world, affecting as many as 8 million people.
What Are The Symptoms of Trachoma?
The symptoms of trachoma in its early stages can be mild, and often start anywhere from five to twelve days after infection. Initial symptoms include:
- Itchy eyes/eyelids (similar to conjunctivitis or pink eye)
- Eye irritation
- Eye discharge (mucus or pus)
When trachoma has gone untreated and the infection has advanced, the symptoms can also include:
- Blurry vision or a cloudy cornea
- Eye pain
- Sensitivity to light
- Swelling in the eye or facial lymph nodes
Is Trachoma Infectious?
Trachoma is caused by bacteria, and therefore is infectious. It can be transmitted from person to person via contact with the eyes or body fluids such as mucus or saliva. Trachoma can also be transmitted via something an affected person has used, such as towels or bed linens.
Flies can also transmit trachoma because they may be attracted to dirty faces. Areas where fly populations are not under control may experience increased incidence of the infection.
How is Trachoma Diagnosed?
Trachoma is caused by bacteria, so diagnosis may involve taking a culture to determine the type of bacteria that has invaded the eye and confirm the diagnosis. Trachoma is caused by a type of Chlamydia (Chlamydia trachomatis).
An eye exam will often reveal telltale signs of infection, such as redness, blood vessel growth in the cornea, and in cases of repeated infection, inner upper eyelid scarring. The eyes could also be dry from a decrease in tear production, which complicates the disease.
Trachoma is a progressive disease, and five stages have been identified by the World Health Organization (WHO):
1. Follicular inflammation. In this stage, the follicles on the inner eyelid are inflamed. With magnification, an eye-care professional can see the inner eyelid and identify the inflamed follicles. The presence of five or more inflamed follicles indicates first-stage trachoma.
2. Intense inflammation. In the second stage, the eyelid is severely inflamed and may also be swollen. The condition is now highly contagious.
3. Scarring. The eyelid begins to develop scars, which can be seen by an eye-care professional under magnification. The scarring may look like white lines. The upper eyelid may also begin showing signs of deformation.
4. Eyelid deformation (trichiasis). The advancing disease causes the upper eyelid to turn in toward the eyeball (a condition known as entropion), which causes the eyelashes to touch the cornea. The persistent scraping of the eyelashes against the cornea can cause scratching and severe pain.
5. Cloudy cornea. In this last stage of trachoma, the scarring and the corneal scratches have become so pervasive that the cornea begins to develop a cloudy appearance. A cornea with such advanced disease is highly susceptible to complications such as secondary infections. When trachoma reaches this stage it tends to result in vision loss or blindness.
Trachoma is typically treated with antibiotics. In most cases, a course of antibiotics can cure the infection. The type of antibiotic used will depend upon what is available in the area where the patient lives.
When an outbreak occurs in an area of the world where trachoma is common in children, all at-risk children and their caregivers may be treated with antibiotics. By treating children who are not showing any symptoms but who may potentially be infected, the spread of trachoma can be contained.
The most commonly used antibiotics to treat trachoma include:
- Azithromycin (Zithromax): This drug is given orally, and while it is more effective than tetracycline, its high cost makes it unavailable in certain areas of the world.
- Tetracycline eye ointment: An antibiotic ointment applied directly to the eyes, this is the treatment that is more commonly used in developing areas because it is more readily available and less expensive. It may not be as effective as an oral antibiotic, however, especially in cases where C. trachomatis has spread to the nose. Recurrence is possible in these cases.
In the most extreme cases, surgery may be used to treat the complications of trachoma. Surgery will not cure an underlying infection, but it can prevent blindness.
Bilamellar tarsal rotation surgery to correct the turned-in upper eyelid can prevent the eyelashes from causing further harm to the cornea. This is a simple procedure that is often done on an outpatient basis. Those who have had this type of surgery are also at reduced risk of having the trachoma recur.
Surgery can also be done to remove the eyelashes from the eye (this procedure is called epilation). This type of surgery is often not permanent, and may need to be done more than once in order to prevent the eyelashes from growing back in and causing more damage to the cornea.
Complications Of Trachoma
Repeated incidences of trachoma can cause the eyelashes to turn inside the eye. This is often very painful, and in severe cases it can lead to scarring, vision loss, and even blindness.
According to the WHO, chronic trachoma typically results in blindness when the affected person is between the ages of 30 and 40. Complications most often occur after multiple infections. Trachoma is highly treatable with antibiotics, and one incidence of the infection does not usually result in scarring or eyelid deformation.
Symptoms may not appear until several days after the bacteria has invaded the eye, which makes prevention difficult in some cases. An infected person can unknowingly spread the disease for several days before recognizing that they have been infected or receiving treatment.
Those at risk should avoid sharing any objects that come into contact with the face — towels and clothing in particular.
Because this infection can be transmitted from person to person, avoiding contact with the eyes and body fluids of a person who is infected can also help prevent others from contracting trachoma.
Flies have also been implicated as a transmitter for C. trachomatis, and getting a troublesome fly population under control can also help stop the spread of trachoma.
Better hygiene and sanitation can also help prevent the spread of trachoma, but this is a difficult task to undertake in developing areas. When traveling in areas where trachoma is common, special precautions should be taken to prevent infection.
Washing hands and faces with clean water at least once a day and avoiding sharing objects that could be carrying C. trachomatis are effective measures. People who have traveled to an area where trachoma is common, especially where there is an outbreak, should be screened for infection.