Laser Surgery May Be Safer Than Contacts

William Mathers, M.D., a professor of ophthalmology at the Casey Eye Institute at the Oregon Health & Science University (OHSU, Portland, USA), reviewed several large, peer-reviewed studies and found a greater chance of suffering vision loss from contact lenses than from laser vision correction, also known as refractive surgery.

Data extrapolated from a study showed the lifetime risk of bacterial keratitis--an infection that causes an inflammation of the cornea and can lead to vision loss--to be one in 100 for contact lenses worn daily. Wearing contact lenses overnight or improper care or cleaning further increases the risk of infection from contacts. The risk of bacterial keratitis has changed little over the years for contact lens wearers and is the same worldwide.

Dr. Mathers also looked at a large study of 32,000 U.S. Armed Forces members who received laser surgery. This study found that the loss of vision of one line on an eye chart was one in 1,250 patients. A loss of two or more lines of vision, which would be more significant but less frequent, was not reported. Data from the OHSU Casey Vision Correction Center showed no cases of vision loss greater than two lines in 18,000 procedures performed over 10 years. The findings were published in a letter in the October 2006 issue of Archives of Ophthalmology.

"Several times a year, I have patients who lose eyes from complications because they've been wearing contacts and they've gotten an infection. By this I mean their eyes have to be physically removed from their bodies,” said Dr. Mathers, a former president of the Contact Lens Association of Ophthalmologists. "It's not that contacts aren't good. They're better than they've ever been. But one cannot assume contacts are safer.”

The calculated risks of vision loss from contact lenses and laser surgery are approximate and subject to change. Highly oxygen-permeable contact lenses and advances in laser surgery should make both safer.



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