Trachoma is a bacterial infection of the eye that can lead to blindness. It presents as chronic inflammation of the conjunctiva – the external tissue lining the eyelid and white of the eye. Trachoma is the leading cause of infectious blindness in the world today. It is estimated that up to 8 million people have permanent blindness due to trachoma, and a further 84 million need treatment if blindness is to be prevented.
The inflammation caused by trachoma infection results in the conjunctiva becoming scarred and roughened, which interferes with the eye’s function to lubricate itself in order to protect the clear front tissue of the eye – the cornea. As the disease continues, the cornea itself becomes scarred. Abnormal blood vessels begin to grow into it, causing reduced vision and in some cases, blindness.
In the very advanced stages of the condition, the eyelid can become so scarred that it turns inwards, forcing the lashes to rub on the cornea. This is extremely painful and damaging.
Trachoma is a communicable disease, meaning it is easily spread from one infected person to another – by direct contact, such as touching infected secretions from the eye, nose or mouth, or by indirect contact, such as touching infected items (sheets, clothing, towels etc.). It can also be spread by flies that seek out the eyes. Trachoma is caused by a particular strain of the bacteria Chlamydia Trachomatis (a different strain of the same bacteria causes the venereal disease commonly known as chlamydia. It is important to note that trachoma is not a sexually transmitted disease).
In the 20th century, trachoma disappeared from developed countries but it remains endemic in parts of Africa and Asia. Australia is the only developed country to have endemic trachoma in some regions. It is still common in many remote Aboriginal communities, where infection rates range from 2 to 50 percent.
Symptoms don’t start to appear until 5–12 days after you have actually been infected. Initial symptoms include:
If untreated, or if the infection is contracted many times, longer term symptoms include:
Trachoma is most common in poverty-stricken and developing communities. It is caused by improper hygiene and lack of education around cleanliness (particularly relating to washing of the face), crowded living areas, scarce clean water supply, flies that have bred in human or animal faeces, bathing in unclean water, and inadequate housing. It is most easily contracted by young pre-school aged children. Anyone who comes into contact with an infected person can also be at risk of contracting the infection.
Trachoma is diagnosed by an ophthalmologist who will conduct a physical eye examination of the patient, look at their medical history, and sometimes take a swab of the eye for laboratory testing.
Treatment is most effective in the early stages of the infection.
Antibiotics are often used to treat the infection in its first instance or in less complicated cases. In most cases, the entire community needs to be treated frequently to prevent re-infection.
Surgery is needed in more severe cases to correct the eyelid deformity and turn the eyelid back outwards.
As with everything, prevention is key. With the goal of eliminating trachoma by the year 2020, the World Health Organization introduced a strategy involving a combination of interventions to help prevent infection in communities where the disease is endemic. This integrated approach is known by the acronym “SAFE”, which stands for Surgery for trichiasis (in turned eyelashes), Antibiotics, Facial cleanliness and Environmental improvement.
In November 2006, the National Trachoma Surveillance and Reporting Unit (NTSRU) was established to provide annual reports on active trachoma in Australia. Information is collected from remote Aboriginal communities where trachoma is endemic. This information is used to guide appropriate treatment strategies, as a public health response.