Trichiasis is the leading infectious cause of blindness worldwide. It is a condition in which the eyelid turns inward and the eyelashes rub against the eye, causing corneal scarring, that can lead to blindness. It results from years of repeated episodes of trachoma, an ocular bacterial infection that is very common in rural areas of developing countries.
The bacteria that cause trachoma are suspected to be spread by contact with hands or clothing of infected individuals. Flies may also transfer the infection from one person to another. Because trachoma is transmitted through close personal contact, it tends to occur in clusters, often infecting entire families and a large majority of people in a given community. The disease usually remains hidden in rural areas of developing countries where people live in overcrowded conditions with limited access to water and health care.
Trichiasis can be corrected by appropriate lid surgery, which returns the inturned eyelashes to their normal position. However, even under the best of circumstances the eyelashes may turn back in (between 16 percent and 50 percent within a few years after surgery). That's why this new Johns Hopkins research is so valuable, says lead researcher Sheila West, Ph.D., of the Dana Center for Preventative Ophthalmology at Johns Hopkins Medicine. In the current study, less than 10 percent of people had their eyelid turn in again within one year after surgery.
In the study, published in the March 2006 issue of the Archives of Ophthalmology, the research team found that a single dose of the antibiotic azithromycin reduces the risk of trichiasis recurring for up to one year after surgery.
The researchers compared the use of one oral dose of azithromycin to six weeks of twice daily topical tetracycline treatment. Researchers found the azithromycin group had one-third fewer recurrences of inturned lashes than the tetracycline group.
"We are delighted with the results of this study. Trichiasis plagues the poorest of the poor, and primarily affects the most underprivileged members of the community, the women. The results of this study have major implications for improving outcomes of trichiasis surgery. The use of a single dose of azithromycin is a relatively straightforward and simple procedure to implement, and in many countries the drug is provided through a free donation program." says West. "Not only have we shown that azithromycin can reduce recurrence, but we have also demonstrated that in the hands of well-trained individuals trichiasis recurrence can be below 10 percent. These results set a new standard for trichiasis surgery and are applicable throughout the world."
The study was funded by a grant from the National Eye Institute, one of the Federal government's National Institutes of Health. Pfizer International provided the azithromycin for the trial as part of a donation to the Ethiopian Ministry of Health. But Pfizer had no role in any part of the study.
The researchers who conducted the study are Sheila K. West Ph.D., Emily S. West, Ph.D., Beatriz Munoz, M.S., and Alemush Imeru from the Dana Center for Preventive Ophthalmology at the Wilmer Eye Institute; Charlotte Gaydos, Dr.P.H., M.S., M.P.H., and Thomas Quinn, M.D. from the Department of Infectious Diseases; Wondu Alemayehu, M.D., M.P.H., and Muluken Melese, M.D. M.P.H., from ORBIS International; and Alemayehu Worku, PhD. from the Department of Community Medicine, Addis Ababa University; Curtis L. Meinert, Ph.D., of the Center for Clinical Trials at the Johns Hopkins Bloomberg School of Public Health.
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The Wilmer Eye Institute http://www.hopkinsmedicine.org/wilmer/index.html
The National Eye Institute www.nei.nih.gov
Journal
Archives of Ophthalmology