Trachoma and Blindness
For many people it is surprising to learn that a bacterial infection can rob someone of their sight, but that is just what happens every year to 10 million people living in 56 different countries. In total around 140 million more people are infected and in danger of going blind. Globally, trachoma is the main infectious causes of blindness but it is entirely preventable and treatable.
What Causes Trachoma?Trachoma is due to an infection by the bacterium Chlamydia trachomatis, which spreads easily from person to person via personal contact, shared clothes or by flies. It is recognised as a disease of poverty – whilst very rare in the industrialised world, its worst effects are seen in the poorest areas of the developing world. In the poorest nations in Africa, over 40% of the population can suffer from trachoma. Children under five are very badly affected because they tend to touch their eyes when playing closely together, so spreading the infection. Women in poor communities are therefore also exposed to the bacteria more often than men and suffer blindness more frequently. Blindness in a mother spells disasters to many families.
Stages of InfectionFive stages of trachoma infection are listed by the World Health Organisation to help with early recognition of the disease. The earlier it is treated, the more the risk of complete blindness is reduced.
In the very early stages, bumps called follicles start to appear inside the upper eyelid. The bumps are usually very tiny and can only be seen with a magnifier. These foci of infection cause intense irritation and the second stage is typified by inflammation of the eyelid. The lids swell up and may start to invert, turning the eyelashes into the eye so that they scrape against the delicate corneal surface. In time, this leads to the third stage of infection, in which the eyelid becomes scarred on its inner surface. Turning in of the eyelids becomes more pronounced. Permanently ingrown lashes are a sign that stage 4 has been reached. This is intensely painful. The inflammation inside the eyelids continues to get worse and the grating of the inturned eyelashes severely damages the cornea, causing it to cloud over. In this final, fifth stage, ulcers also form on the cornea, and complete blindness is inevitable.