Specially trained nurses and health assistants are as effective as ophthalmologists in performing vision-preserving surgery for a blinding disease called trachoma trichiasis, a new review has found.
The review also found that village-based surgery was as safe and effective as surgery performed in hospitals, while reducing travel time and expense for patients.
Trachoma, an eye disease caused by bacterial infection, is the leading cause of preventable blindness worldwide. The World Health Organization estimates that 8 million people are visually impaired or blind due to trachoma. Another 84 million are at risk of losing their eyesight due to active infection with Chlamydia trachomatis, the culprit bacteria.
"There are multiple personal and societal barriers to surgery for trachoma trichiasis," said lead author David Yorston, of the Tennent Institute of Ophthalmology in Glasgow, Scotland. "By delivering surgery in the community we can reduce the distance barrier, but it is more difficult to eliminate the others."
The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates research in all aspects of health care. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing trials on a topic.
Although no region of the world has been untouched by trachoma, today the disease is largely confined to developing countries where poverty, crowding and a lack of clean water and hygiene fuel the transmission of infection from person to person.
A single bout of infection is not enough to cause blindness. However, with repeated infections, the inside of the upper eyelid becomes riddled with scar tissue. As the scar tissue contracts, the eyelashes turn inward and brush against the cornea. This is trichiasis.
Left untreated, the constant irritation of the cornea by the inward-turning eyelashes possibly in combination with secondary bacterial infections eventually leads to blindness. Even before vision is destroyed, the disease is painful and disabling, confining many of those afflicted to their homes.
The WHO is leading a global initiative to eliminate trachoma as a blinding disease by 2020 with a four-part strategy called SAFE: surgery, antibiotics, facial cleanliness and environmental hygiene. While the final three parts of this strategy are targeted at preventing the spread of trachoma, the first part is focused on improving the health and well-being of those with trachoma trichiasis, who are at risk of going blind.
In their review, the Cochrane researchers analyzed the findings from seven studies that compared different approaches to treating trachoma trichiasis.
Three of the studies compared different ways of performing surgery to correct the inward rotation of the eyelids and prevent the eyelashes from rubbing against the cornea. While one trial found that one type of surgery was more effective than another, the other two trials showed little difference.
"There is wide variation in outcomes between different surgeons," said Yorston. "In view of this variation, I think that either operation can be effective if the surgery is meticulous, but neither operation will work if it is performed by a poorly supervised surgeon with inadequate equipment."
A study conducted in Gambia found that patients who received postsurgical azithromycin (the same antibiotic that is used for trachoma prevention) did not have better outcomes compared to patients given the usual postsurgical antibiotic, tetracycline eye ointment.
An Ethiopian study that evaluated whether ophthalmologists achieved better surgical outcomes than specially trained ophthalmic assistants found no significant differences in complications or recurrence of trichiasis. And a study in Gambia that compared outcomes for village-based and hospital-based surgery found that results were similar in both settings. However, village-based surgery was less costly and time-consuming for patients.
"I think it's completely appropriate for ophthalmic assistants to do this surgery, and it's a good way to solve the shortage of ophthalmologists," said Thomas Lietman, M.D., director of the WHO Collaborating Center at the University of California, San Francisco. "Since it's not intraocular surgery and the infection risk is low, you don't need a great operating area. Community-based surgery wouldn't be all that difficult to do."
A final randomized study compared results of two short-term nonsurgical techniques for minimizing contact between the eyelashes and the cornea. The more commonly used technique, called epilation, involves removing the eyelashes. The alternative is to apply double-sided tape to force the eyelashes away from the eyeball. This study found that the tape was more effective as a temporary measure, but it had to be replaced weekly.
According to Lietman, there is reason to be optimistic that the WHO goal of eliminating trachoma by 2020 can be achieved.
"I think we're on target and maybe even ahead of schedule," he said. "Infection is being reduced with antibiotics, and lids are being operated on, saving vision more immediately. Also, trachoma is disappearing as areas get wealthier. War and unrest may be what prevents the last few areas from being cleared in time for 2020."