Trachoma is an infectious disease caused by bacterium Chlamydia trachomatis. The infection causes a roughening of the inner surface of the eyelids. This roughening can lead to pain in the eyes, breakdown of the outer surface or cornea of the eyes, and eventual blindness. Untreated, repeated trachoma infections can result in a form of permanent blindness when the eyelids turn inward.
The bacteria that cause the disease can be spread by both direct and indirect contact with an affected person’s eyes or nose. Indirect contact includes through clothing or flies that have come into contact with an affected person’s eyes or nose. Children spread the disease more often than adults. Poor sanitation, crowded living conditions, and not enough clean water and toilets also increase spread.
Trachoma is the leading preventable cause of blindness worldwide. The World Health Organization (WHO) estimates that 6 million people have been blinded by trachoma. Most blinding trachoma occurs in poor areas of Africa. Among children under 5, prevalence of active trachoma infections can be 60 percent or more.
Signs and symptoms of trachoma usually affect both eyes and may include:
- Mild itching and irritation of the eyes and eyelids
- Discharge from the eyes containing mucus or pus
- Eyelid swelling
- Light sensitivity (photophobia)
- Eye pain
Young children are particularly susceptible to infection. But the disease progresses slowly, and the more painful symptoms may not emerge until adulthood.
The World Health Organization has identified five stages in the development of trachoma:
- Inflammation — follicular. The infection is just beginning in this stage. Five or more follicles — small bumps that contain lymphocytes, a type of white blood cell — are visible with magnification on the inner surface of your upper eyelid (conjunctiva).
- Inflammation — intense. In this stage, your eye is now highly infectious and becomes irritated, with a thickening or swelling of the upper eyelid.
- Eyelid scarring. Repeated infections lead to scarring of the inner eyelid. The scars often appear as white lines when examined with magnification. Your eyelid may become distorted and may turn in (entropion).
- Ingrown eyelashes (trichiasis). The scarred inner lining of your eyelid continues to deform, causing your lashes to turn in so that they rub on and scratch the transparent outer surface of your eye (cornea).
- Corneal clouding. The cornea becomes affected by an inflammation that is most commonly seen under your upper lid. Continual inflammation compounded by scratching from the in-turned lashes leads to clouding of the cornea.
All the signs of trachoma are more severe in your upper lid than in your lower lid. With advanced scarring, your upper lid may show a thick line.
In addition, the lubricating glandular tissue in your lids — including the tear-producing glands (lacrimal glands) — can be affected. This can lead to extreme dryness, aggravating the problem even more.
Trachoma is caused by certain subtypes of Chlamydia trachomatis, a bacterium that can also cause the sexually transmitted infection chlamydia.
Trachoma spreads through contact with discharge from the eyes or nose of an infected person. Hands, clothing, towels and insects can all be routes for transmission. In developing countries, eye-seeking flies also are a means of transmission.
Factors that increase your risk of contracting trachoma include:
- Poverty. Trachoma is primarily a disease of extremely poor populations in developing countries.
- Crowded living conditions. People living in close contact are at greater risk of spreading infection.
- Poor sanitation. Poor sanitary conditions and lack of hygiene, such as unclean faces or hands, help spread the disease.
- Age. In areas where the disease is active, it’s most common in children ages 4 to 6.
- Sex. In some areas, women’s rate of contracting the disease is two to six times higher than that of men.
- Flies. People living in areas with problems controlling the fly population may be more susceptible to infection.
- Lack of latrines. Populations without access to working latrines — a type of communal toilet — have a higher incidence of the disease.
One episode of trachoma caused by Chlamydia trachomatis is easily treated with early detection and use of antibiotics. Repeated or secondary infections can lead to complications, including:
- Scarring of the inner eyelid
- Eyelid deformities, such as an inward folding eyelid (entropion) or ingrown eyelashes (trichiasis)
- Corneal scarring or cloudiness
- Partial or complete vision loss
If you’ve been treated for trachoma with antibiotics or surgery, reinfection is always a concern. For your protection and for the safety of others, be sure that family members or others you live with are screened and, if necessary, treated for trachoma.
Trachoma can occur worldwide but is more common in the Middle East, North Africa, sub-Saharan Africa, and areas of southern Asia and China. When in regions where trachoma is common, take extra care in practicing good hygiene, which can help prevent infection.
Proper hygiene practices include:
- Face washing and hand-washing. Keeping faces clean may help break the cycle of reinfection.
- Controlling flies. Reducing fly populations can help eliminate a major source of transmission.
- Proper waste management. Properly disposing of animal and human waste can reduce breeding grounds for flies.
- Improved access to water. Having a fresh water source nearby can help improve hygienic conditions.
No trachoma vaccine is available, but prevention is possible. The World Health Organization (WHO) has developed a strategy to prevent trachoma, with the goal of eliminating it by 2020. The strategy, titled SAFE, involves:
- Surgery to treat advanced forms of trachoma
- Antibiotics to treat and prevent the infection
- Facial cleanliness
- Environmental improvements, particularly in water, sanitation and fly control
Your doctor can diagnose trachoma through a physical examination or by sending a sample of bacteria from your eyes to a laboratory for testing. But lab tests aren’t always available in places where trachoma is common.
Trachoma treatment options depend on the stage of the disease.
In the early stages of trachoma, treatment with antibiotics alone may be enough to eliminate the infection. Your doctor may prescribe tetracycline eye ointment or oral azithromycin (Zithromax). Azithromycin appears to be more effective than tetracycline, but it’s more expensive.
The World Health Organization (WHO) recommends giving antibiotics to an entire community when more than 10 percent of children have been affected by trachoma. The goal of this guideline is to treat anyone who has been exposed to trachoma and reduce the spread of trachoma.
Treatment of later stages of trachoma — including painful eyelid deformities — may require surgery. WHO guidelines recommend surgery for people with the advanced stage of trachoma.
In eyelid rotation surgery (bilamellar tarsal rotation), your doctor makes an incision in your scarred lid and rotates your eyelashes away from your cornea. The procedure limits the progression of corneal scarring and may help prevent further loss of vision.
If your cornea has become clouded enough to seriously impair your vision, corneal transplantation may be an option that may improve vision. Frequently, however, with trachoma, this procedure doesn’t have good results.
You may have a procedure to remove eyelashes (epilation) in some cases. This procedure may need to be done repeatedly. Another temporary option, if surgery isn’t an available option, is to place an adhesive bandage over your eyelashes to keep them from touching your eye.