However, LASIK patients tend to recover their vision faster than PRK patients, which may be part of the reason their number has grown rapidly since the late 1990s, said Dr. Alex Schortt and Dr. Bruce Allan of the Moorfields Eye Hospital in London.

LASIK patients also report less pain after surgery than PRK patients, although they tend to be more uncomfortable during the actual surgery, the researchers found.

Schortt says patients might prefer these "side effects" associated with LASIK, but "none of the individual studies included in this review demonstrated a significant [vision] advantage for either treatment," he said.

"There are cases for both procedures where LASIK would be best for one patient and PRK would be best for another patient," said Melissa Bailey, Ph.D., an optometrist at the Ohio State University College of Optometry. "It really depends on individual patient factors," such the thickness of tissues in the eye and severity of the nearsightedness, she said.

The review appears in the current issue of The Cochrane Library, a publication of The Cochrane Collaboration, an international organization that evaluates medical research. Systematic reviews draw evidence-based conclusions about medical practice after considering both the content and quality of existing medical trials on a topic.

Typically, the nearsighted eye is longer than usual from back to front. This shape causes the eye to focus on light from distant objects in front of instead of directly on the retina, the part of the eye that transforms light into the nervous system signals that make up vision. The misfocus blurs the appearance of far-off objects such as highway signs or faces seen at a distance in a crowd.

LASIK (laser-assisted in-situ keratomi
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Contact: Bruce Allan
bruce.allan@ucl.ac.uk
44-207-566-2045
Center for the Advancement of Health
18-Apr-2006