Trachoma
Trachoma (granular conjunctivitis, Egyptian ophthalmia) is a prolonged infection of the conjunctiva caused by the bacterium Chlamydia trachomatis.
Trachoma is the leading preventable cause of blindness in the world; it results from chronic or repeated infections with certain nonsexually transmitted strains of C. trachomatis. Trachoma is common in poverty-stricken parts of dry, hot countries in North Africa, the Middle East, the Indian Subcontinent, and Southeast Asia. In the United States, trachoma is rare, occurring occasionally among Native Americans and among immigrants from areas where trachoma is common. The disease occurs mainly in children, particularly those between the ages of 3 and 6. Older children and adults are much less likely to have the disease because of increased immunity and better personal hygiene. Trachoma is contagious in its early stages and may be transmitted by eye-hand contact, by certain flies, or by sharing contaminated articles, such as towels, handkerchiefs, and eye makeup.
Symptoms
Trachoma usually affects both eyes. The conjunctivae become inflamed, red, and irritated, and the eyes water excessively. Sensitivity to bright light occurs.
In the later stages, blood vessels gradually grow across the cornea (neovascularization), obstructing vision. In some people, the eyelid is scarred in such a way that the eyelashes turn inward (trichiasis). As the person blinks, the eyelashes rub against the cornea, causing infection and permanent damage; impaired vision or blindness occurs in about 5% of people with trachoma.
Diagnosis and Treatment
Doctors suspect trachoma because of the appearance of the eyes and the duration of symptoms. The diagnosis can be confirmed by sending a sample from the eye to a laboratory, where the infecting organism is identified.
Treatment consists of the antibiotic erythromycin or a tetracycline, which is taken by mouth for 3 to 5 weeks. The newer antibiotic, azithromycin, can be used once per week for 1 to 3 weeks. Tetracycline or erythromycin eye ointments are effective, but they must be applied for 4 to 6 weeks. If the condition damages the eyelid, conjunctiva, or cornea, surgery may be needed.
Because the disease is contagious, reinfection commonly occurs. Regular hand and face washing helps prevent the spread of infection. Doctors often give antibiotics to entire neighborhoods where there are many people with trachoma.
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