Laser eye treatments for refractive disorders, such as nearsightedness, farsightedness, astigmatism and presbyopia, seek to decrease the reliance on glasses and contact lenses and increase visual acuity. Though the surgery, commonly referred to as LASIK, is usually successful in increasing acuity, several common side effects are associated with the procedure. Some of these side effects are relatively minor and some, in rare cases, are more extreme and serious.
Dry Eyes
According to a study in the March 2006 "American Journal of Ophthalmology," dry eye symptoms after laser eye surgery are common, affecting approximately 50 percent of patients within six months of the procedure. Patients with severe dry eyes before surgery are usually eliminated as candidates because of the exacerbated symptoms following the surgery. Symptoms include feelings of dry, itchy, raw eyes sometimes with associated redness and a foreign body sensation. Moisturizing eyedrops and tear duct punctal plugs to retain moisture on the eye surface are often recommended.
Visual Aberrations
According to the FDA, complaints of visual aberrations are common after laser eye surgery. Aberrations include double vision and problems with glare and halos, which often occur at night. Other aberrations include decreased contrast sensitivity and the appearance of starbursts when looking at certain objects. One cause of visual aberrations is a large pupil diameter that outsizes the laser treatment zone.
Refractive Overcorrection, Undercorrection or Astigmatism
Laser eye treatments involve using a laser to create a flap on the surface of the cornea and then reshaping the cornea accordingly to correct the patient's current refractive error. Eye surgeons must make precise laser measurements in order to correct the nearsightedness, farsightedness or astigmatism. Unfortunately, measurements and the healing cornea may not cooperate for the "perfect" correction. This results in overshooting or undershooting the prescription or creating new amounts of astigmatism. If this resulting error is minor, the patient experiences little to no blur. According to the Mayo Clinic, if the resulting error is large, then the patient will experience blur that may require the use of prescription glasses, contact lenses or a touch-up laser procedure.
Flap Side Effects
When the cornea is ablated with the laser and the flap is created, this flap must then lie flat and heal effectively after surgery. When complications occur due to poor flap healing, significant side effects may occur. Cells from the top surface of the cornea, called the epithelium, can grow underneath the flap and cause distortion and blur. Follow-up care after laser surgery is important to detect possible epithelial in-growth. Additionally, folds and wrinkling around and in the fold can occur. Infection around the flap is also possible, and symptoms of red, swollen and sometimes painful eyes may result. It is important following laser eye surgery to evaluate overall healing and monitor the flap and so, according to the FDA, follow-up with the doctor within the first 48 hours and then at recommended intervals is crucial.
References
- All About Vision: Lasik Risks and Complications
- Mayo Clinic: Lasik Eye Surgery
- "American Journal of Ophthalmology"; The Incidence and Risk Factors for Developing Dry Eye After Myopic LASIK Procedure; William D. Mathers; March 2006
- FDA: Lasik: What should I expect
