Diseases

Blindness from trachoma is essentially totally preventable at relatively low cost. This can be accomplished by teaching sanitation, especially cleanliness of the face, and treating all infected individuals within a heavily infected community with oral antibiotics or antibiotic eye ointment early in the disease process. Many countries have eradicated trachoma using these steps.

Trachoma affects the eyelids and conjunctiva (outside covering) of the eye, usually with very little discomfort until later in the disease. When infected, the conjunctival covering of the eye becomes red and irritated (inflamed). Repeated infections by the trachoma bacteria are common and, unless treated, can result in scarring of the conjunctival surface of the lids. The lids become scarred and the lid margins may turn in, causing eye irritation and pain followed by scarring of the cornea by the inward-turned lashes (trichiasis), which scrape the cornea. Corneal scarring results in decreased or total loss of vision. In order to see properly, it is necessary for the cornea (front window of the eye) to remain clear.

Although there are bacteriologic and other tests available, trachoma is commonly diagnosed by examining the eyes and eyelids of the patient. In the rare cases seen in developed countries, the diagnosis is usually by the ophthalmologist. However, in the third world, ancillary personnel are very capable of being trained to make this diagnosis. Trachoma should be suspected from the history and symptoms. It then can be confirmed by an examination which can be performed within the community without the aid of sophisticated office equipment. If equipment is available, the vision is measured and the eye is inspected with a slit lamp (biomicroscope), with which characteristic changes in the lids, tear film, conjunctiva, and cornea can more easily be seen.

Many individuals who have trachoma infection of the eyes will have it only once and scarring will not necessarily occur. However infections may reoccur until proper diagnosis is made and treatment is instituted.

Trachoma causes irritation of the eye, starting with simple redness of the eye and lids, progressing to inward turning of the lids and irritation and scarring of the cornea, which may then progress to an opaque cornea resulting in blindness. These complications are avoidable with adequate diagnosis and treatment. With development of the later stages of trachoma with scarring of the lids and conjunctiva, vision is often decreased to the point where the individual is no longer able to work, resulting in disruption of the family. Children drop out of school to take care of a parent with blindness and the family may have severe economic problems. Because of profound visual disturbance or blindness, there may be an increased number of related injuries or even accidental death.

The affected individual develops redness and irritation of the eyes with tearing, which can progress through repeated new infection to scarring and visual loss.

Although trachoma is caused by a small parasitic bacteria, poor sanitation, unclean water supply, and reduced personal and community hygiene allow the bacteria to infect and reinfect eyes of individuals living in endemic areas. Prevention of vision loss requires adequate, prompt treatment, in addition to education and teaching proper hygiene to the parents and children. Trachoma is an ancient disease and was once prevalent throughout the world except in colder climates. It has been eliminated in more advanced countries but is still endemic in about 55 third-world nations, primarily in Africa and the Middle East. Approximately 10 million people have significant visual loss from the corneal scarring caused by trachoma. Trachoma is spread by direct or indirect contact with eye, nose, or throat secretions of an individual with trachoma, or indirectly via flies or other insects carrying those secretions on their legs or bodies. Common denominators are poor hygiene, unsanitary water supplies, and shared towels. It is most common in small children (3-5 years of age) who spread it to their siblings, mothers, and playmates. Within endemic areas, the incidence of the infection is highly variable from village to village and concentrates in families or other pockets. Throughout the entire world, Chlamydia trachomatis also causes sexually transmitted disease and conjunctivitis of the newborn, transmitted from the mother during the birth process.

If diagnosed early, before scarring of the cornea, the prognosis is excellent. There is an International Trachoma Initiative (ITI) dedicated to eliminating trachoma by following the World Health Organization (WHO) SAFE strategy. It is partnering with governmental and private organizations, such as the Bill & Melinda Gates Foundation. If successful, trachoma may become a disease of the past in two generations; 15 countries are targeted for elimination of trachoma by 2020.

The treatment is relatively simple. A single oral dose of antibiotic is the preferred treatment, plus making safe water available and teaching simple cleanliness. Because of cultural differences and widespread poverty in endemic areas, this regimen is difficult to implement on a universal scale. The World Health Organization (WHO) developed the SAFE strategy.

• S = surgical care
• A = antibiotics
• F = facial cleanliness
• E = environmental improvement

Treatment involves screening communities for the presence of trachoma in children 1-9 years of age. When over 10 % are found to have clinical disease, the entire community is treated with antibiotics. In areas with less disease, only targeted groups are treated. Due to the contagiousness of trachoma, it is necessary to treat all who might be in contact with the infected individuals. The actual treatment is the onetime use of use of azithromycin (Zithromax) pills (currently the treatment of choice) or the topical use of 1% tetracycline (Achromycin) ointment. When trachoma has progressed to inward-turning of the lashes, surgery is necessary to correct this and prevent the lashes from scarring the cornea. Performance of this surgery can be taught to nurses or other medical personnel. If significant corneal scarring already exists, corneal transplantation surgery may be required, which should be performed by an ophthalmologist.

Trachoma is a contagious bacterial infection which affects the conjunctival covering of the eye, the cornea, and the eyelids. It is often associated with poverty and lack of proper hygiene. Trachoma is caused by the Chlamydia trachomatis bacteria and is essentially totally preventable and curable. It is the leading infectious cause of blindness in the world. Approximately 80 million people in the world have active trachoma. The majority of these are children. The disease is found predominantly in poor tropical or semi-tropical countries.

Since the cause is well understood and treatment is effective, research is concentrating on methodology to deliver the treatment efficiently to endemic areas of the world.