This article is best viewed in a PDF Format.
|
|
These dramatic and sad images were sent in by Alison Hudson some years back to one of our anterior imaging competitions. They were taken when on a charity visit to Africa. Dramatic, because of the extent of corneal opacification and adnexal scarring. Sad because they are the result of a condition that is still very common throughout the world and is preventable.
Trachoma is still the leading cause of blindness through infection and of the 41 million people estimated to be carrying the active infection 8 million suffer visual impairment because of it. The name comes from the Greek for 'rough eye' and stems from the fact that repeated infection inevitably leads to cicatricial entropion (scar tissue causes the lids to invert) and trichiasis with the result that the corneas are constantly abraded, resulting in corneal neovascularisation and opacification. Destruction of goblet cells and damage to the lachrymal system leave the eye dry. All of this leads to a long-term painful and damaged eye with concurrent loss of vision.
Trachoma is caused by Chlamydia trachomatis and is spread by direct contact with eye, nose, and throat secretions from affected individuals, or contact with fomites (inanimate objects), such as towels and/or washcloths, that have had similar contact with these secretions. Flies can also be a route of mechanical transmission. Exposure to flies, lack of hygiene facilities and lack of anti-infective medicines all contribute to the condition being widespread in areas of lower socio-economic status. Trachoma control is usually described in terms of the acronym SAFE surgery for trichiasis, antibiotics, face washing, environmental improvement. More details of the disease are highlighted in our forthcoming CET articles looking into global blindness in the coming weeks.
It is interesting to note that trachoma infection in so-called developed countries is still a concern. Immigrants to the US via the New York Ellis Island facility were checked for several conditions before admission and trachoma was high on the list of concerns as recently as the second world war. Would-be US citizens were lined up in front of military medical personnel and inspected for a group of conditions. Because of the contact infection of trachoma, people were 'buttonhooked' by means of a rod and hook passed through their buttonhole while being inspected. Anyone showing conjunctivitis signs were given a chalk mark 'C' on their clothes, and if trachoma was suspected they were designated as 'CT'. The latter may well have been enough for refused entry to the US. It is said that many people only managed to enter the US by surreptitiously rubbing off the chalk mark when unobserved or even turning their jackets inside out to avoid refusal. ?