Serious complications from LASIK surgery are rare, said spokeswoman Jan Beiting at the American Society of Cataract and Refractive Surgery/American Society of Ophthalmic Administrators in Fairfax, Va.
Here are data for 1,700 patients from the years 1996-98 contained in 1999 applications seeking U.S. Food and Drug Administration approval of two excimer lasers, Visx Star and Summit Apex Plus, for use in treating nearsightedness:
* Loss of best spectacle-corrected vision--to the extent that at least two lines on a standard eye chart were lost--occurred in 0.6% to 1.9% of cases. FDA guidelines called for a rate of less than 5%.
* Best spectacle-corrected vision worse than 20/40, 0.4%. FDA guidelines: less than 1%.
* Induced astigmatism, zero to 1%. FDA guidelines: less than 5%.
* Correctable adverse events such as flap edema or wrinkling, less than 1% for each of six possibilities. FDA guidelines: less than 1%.
* Cumulative minor complications at any point during and after surgery: 2.7% to 4.2%.
Subjective complications from LASIK--problems with glare or halos, or loss of night vision that cannot be detected with instruments--are tough to track, but "we believe that rate is well below 5% and probably less than 1%," Beiting said.
Results were best for patients with less serious vision problems, the FDA applications said.
Between 92% and 95% of patients achieved uncorrected vision of 20/40 or better. FDA guidelines called for those results in 85% of cases.
Health Canada relies on FDA data, officials said.