Laser Vision Correction
Today, laser vision correction is one of the
world’s most commonly performed elective procedures. Endorsed by the National
Institute of Health and Clinical Excellence (NICE), it is currently estimated
that over 32 million procedures have been performed worldwide.
Laser vision correction involves precisely
reshaping the cornea (the transparent window which covers the coloured part of
the eye). The treatment is surprisingly quick and uses a cold, high-precision
beam of light that is exactly programmed to remove a microscopic layer of the
cornea which alters its curvature, thus shifting the focus of incoming light to
the correct plane (the retina). This, amazingly, is a very effective approach
to correcting vision and the aim of treatment is to totally eliminate, or
reduce the need for glasses and contact lenses to correct vision.
There are two fundamental types of laser
vision correction: LASIK and LASEK.
LASIK
LASIK,
or Laser Assisted In Situ Keratomileusis, is the most common form of laser
vision correction and this is mainly due to the fact that because it is
performed under a protective layer of corneal tissue, there is quicker healing
and less risk of corneal haze and scarring. It is possible to treat a broad
range of refractive errors with LASIK.
The procedure involves creating a thin flap
in the superficial part of the cornea. The laser is then applied to the
mid-corneal structure and the flap is replaced. The eye starts to recover
immediately.
LASIK is a virtually painless procedure and
the vast majority of patients will require only anaesthetic eye drops to numb
the eye prior to treatment. Most patients will report no pain at all during the
procedure, although some describe a mild feeling of pressure or vibration
during the course of the procedure. Post-treatment, there may be mild
discomfort, which is relieved by using the prescribed eye drops and by resting
the eyes.
LASEK
LASEK,
or Laser Assisted Epithelial Karatomileusis is the main alternative to LASIK.
This is a surface procedure and involves
preserving the thin corneal epithelium by lifting it from the surface of the
eye before the laser is applied to reshape the eye. After the LASEK procedure,
the epithelium is gently replaced back onto the surface of the eye.
LASEK is the procedure of choice if the
cornea is too thin or steep for LASIK, or in cases where it may be difficult to
create a LASIK flap.
Patients who have undergone LASEK, often find
that their eyes heal more slowly than those who have had LASIK. They also often
report more discomfort during the healing process for a few days after initial
treatment. With LASEK, it usually takes a little longer to resume good vision,
typically between four and seven days post-treatment but the final visual
outcome for LASIK and LASEK remain very similar.
