Trachoma: a review.

Trachoma is a leading cause of preventable blindness worldwide. The disease is caused by an intracellular epithelial gram-negative bacterium, Chlamydia trachomatis. The presence of children, overcrowding, and the lack of water in the household are factors that predispose to the transmission of the disease. The disease may remain asymptomatic but some patients many complain of redness, irritation, and ocular discharge. The principal initial clinical manifestation is a follicular conjunctivitis that may lead to conjunctival scarring, entropion, trichiasis, corneal thinning, and ulceration. Some patients develop corneal scars that lead to loss of vision. Despite the remarkable progress in our understanding of Chlamydial infections, the basic mechanisms involved in tissue damage and scarring remain to be elucidated. There are several effective therapeutic modalities for trachoma. Azithromycin oral single dose was found to be safe and effective in children with active trachoma. Conjunctival biopsy specimens obtained from adult patients receiving a single oral dose of azithromycin showed sustained high levels of azithromycin (above MIC of chlamydia) for up to 2 weeks after intake. These prolonged high levels of azithromycin in the conjunctival tissue following a single oral dose makes the drug suitable for the treatment of endemic trachoma.