Laser surgery takes better without humidity

The hotter and more humid it is when patients get laser surgery to correct poor vision, the more likely they are to need fine-tuning, researchers from Wake Forest University in North Carolina reported last week. September was the worst month to get the laser surgery, with 50 percent of eyes needing a follow-up procedure compared to none in drier winter months, said Dr. Keith Walter, assistant professor of ophthalmology at Wake Forest who published his findings in the Journal of Cataract and Refractive Surgery. Walter, who performed the surgery on 368 eyes, said he found that a 10 percent increase intreatment-room humidity meant an additional nine out of every 100 patients needed repeat treatment. Results also were influenced by outdoor temperatures and humidity in the two weeks before surgery. Walter said the extra moisture in the air may reduce the laser energy absorbed by the cornea, which is reshaped during the procedure. "This is the first study to show that environmental factors can affect Lasik outcomes," Walter stated in a release. "For best results, physicians should take these factors into account when calibrating laser equipment."
REUTERS