By Dr Lee Mun Toong
In most cases the improved vision from Femto LASIK surgery provides is permanent.
But in a limited number of cases — usually due to changes that can occur in the lens inside the eye (can caused by cataract or other eye pathologies as well), with or without LASIK surgery — some nearsightedness, farsightedness and/or astigmatism can return over time, causing blurry vision. If a regression of this sort occurs and becomes bothersome, a follow-up procedure called a LASIK enhancement usually can be performed to restore clear vision or treat the underlying pathologies.
A study published in the Journal of Cataract & Refractive Surgery evaluated the long-term stability of Lasik.
Researchers in the UK monitored the vision of 46 patients for a period of 18 years. Prior to surgery, all patients were myopic, with an average eyeglass prescription of -4.86 D (range: -2.75 to -7.37 D).
Patients who were under age 40 at the time of their LASIK procedure had an average regression of -0.54 D during the 18-year follow-up period. Those who were over age 40 when they underwent LASIK had an average regression of only -0.05 D.
There also was a significant difference when patients were sorted by sex. Women experienced an average regression of -0.40 D over the 18-year follow-up period; men experienced an average regression of -0.08 D.
In all cases, the laser procedure was safe, with no long-term complications.
Another long-term study of the stability of laser vision correction published in the American Journal of Ophthalmology several years earlier found that among patients who underwent LASIK surgery for the correction of up to -10.0 D of myopia, approximately only 6 % of patient chose to undergo a LASIK enhancement within 10 years due to myopic regression.
In many cases, people who experience minor refractive changes after LASIK aren’t bothered by the change and don’t feel a need for additional vision correction. Others choose to wear prescription eyeglasses only for specific activities (driving at night, for example).