The principal signs and symptoms in the early stages of trachoma include:
- Mild itching and irritation of the eyes and eyelids
- Discharge from the eyes containing mucus or pus
As the disease progresses, later trachoma symptoms include:
- Marked light sensitivity (photophobia)
- Blurred vision
- 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 a grading system with five stages in the development of trachoma, including:
- 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. Secondary infection can lead to development of ulcers on your cornea and eventually partial or complete blindness.
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.
When to see a doctor
Call your doctor if you or your child has itching, irritation or discharge from the eyes, especially if you recently traveled to an area where trachoma is common. Trachoma is a contagious condition, and it should be treated as soon as possible to prevent further infections.
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 the world's developing countries, flies are a major 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. Women contract the disease at rates two to six times higher than those for men.
- Poor access to water. Households at greater distances from a water supply are more susceptible to infection.
- 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. However, repeated infection can lead to complications, including:
- Scarring of the inner eyelid
- Eyelid deformities
- Inward folding of the eyelid (entropion)
- Ingrown eyelashes
- Corneal scarring or cloudiness
- Partial or complete vision loss
If you're traveling to parts of the world where trachoma is common, be sure to practice good hygiene to prevent infection.
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.
Proper hygiene practices include:
- Face washing and hand-washing. Keeping faces clean, especially children's, can 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.
Although no vaccine is available, trachoma prevention is possible. The World Health Organization (WHO) has developed a health strategy to prevent trachoma, with the goal of eliminating trachoma in the world by 2020. The strategy is titled SAFE, which includes:
- Surgery to treat advanced forms of trachoma
- Antibiotics to treat the infection and prevent further spread of infection
- Facial cleanliness
- Environmental improvements, particularly in water, sanitation and fly control, to lower disease transmission