Laser refractive surgery

What is laser refractive surgery?

Laser refractive surgery is an effective and permanent treatment for poor vision due to short-sightedness (myopia), long-sightedness (hyperopia) and astigmatism replacing the need to wear glasses or contact lenses.

Refractive surgery corrects refractive error by using an excimer laser. Excimer lasers have a cold beam that is very precise – removing approximately a quarter of 1000th millimetre with each pulse of laser energy. The laser removes a precalculated microscopic amount of tissue from the deeper layers of the cornea, gently reshaping the cornea to improve its focussing ability and so improve vision.

Who is suitable for laser refractive surgery?

Suitable candidates should be at least 21 years old, have healthy eyes, with a good standard of vision when wearing glasses or contact lenses, a stable prescription and be within the treatment range (generally from +4 diopters long-sight to –11 diopters short-sight with up to 4 diopters of astigmatism).

You would not be suitable for if you:

• Have a prescription that is outside the treatment range of the laser (although other, non-laser treatments may be suitable)
• Are pregnant or expect to become pregnant within six months following the LASIK procedure.
• Have collagen or autoimmune disease
• Are immuno-compromised or on any drugs or therapy which suppress the immune system.
• Show signs of keratoconus
• Have glaucoma
• Have herpes simplex
• Have a disease or are on medication that may affect wound healing
• Have residual or recurrent or active ocular disease(s) or abnormality except for myopia or hyperopia in either eye.
• Only see in one eye
• Have unstable or uncontrolled diabetes
• Have progressive myopia or hyperopia
• Have amblyopia (lazy eye)

What is LASIK?

LASIK, which stands for Laser Assisted In-Situ Keratomileusis, is a form of refractive surgery that combines microsurgery and excimer laser treatment. LASIK is a procedure whereby the surface part of the cornea is cut with an automated instrument, such that it can be lifted away from the rest of the eye, remaining attached by a thin hinge of uncut tissue. This exposes the deeper layers of the cornea which can then be lasered to alter the shape and achieve refractive correction. After the laser treatment the top flap is repositioned, and heals naturally without the need for stitches.

What is PRK/LASEK?

PRK/LASEK stands for Photo Refractive Keratectomy or Laser Assisted Epithelial Keratomileusis. It is similar to LASIK, but involves laser treatment to the cornea without first cutting a flap. Instead, the very fine skin on the surface of the cornea is softened with a solution of alcohol and then lifted, the laser treatment is applied as with LASIK, and the surface layer of cells can then be repositioned or allowed to regrow.

PRK/LASEK does not require the cutting of a corneal flap, and so avoids some of the risks associated with LASIK. As with LASIK, the procedure itself is painless, but healing is more painful than with LASIK and the recovery of vision slower.