| Links
& Resources |
 |
www.lasikinstitute.org
- probably the best source of well-balanced information
on LASIK for both the public and physicians |
 |
www.eyenet.org
- the home page of the American Academy of Ophthalmology |
 |
www.ascrs.org
- a comprehensive link to relevant information
on eye health and refractive surgery |
|
|
PRK
( photorefractive keratectomy) was
the original laser vision correction procedure and
has been successfully used to treat hundred of thousands
of people since the 1980's. PRK is considered safe
and effective for patients with low to moderate
myopia, with or without astigmatism, and low to
moderate hyperopic. It is still widely used now.
However it differs from Lasik, in being performed
on the surface of the cornea, after removing the
corneal epithelium, Today, PRK is more commonly
referred to as " surface ablation," meaning
a laser procedure that is applied to the surface
of the cornea.
Steps
to the Procedure
PRK
involves removal of the top surface (first
layer of cells) level of the cornea called 'epithelium'.
This exposes the inner cornea, which the eximer
laser will resculpt. The whole PRK procedure itself
is usually completed in less than five minutes and
is painless. A bandage contact lens is usually placed
on the eye for 3 days. Once the epithelium is healed,
usually on the third post-operative day, the bandage
contact lens is removed
Because
PRK sculpts the outer surface of the cornea, patients
will experience some discomfort/pain during the
first 48 hours after the procedure. Eye medications
and pain relief medication will be given to the
patients. Usually patient will feel much better
after 2 days. Useful vision of PRK patient usually
returns within one week depending on the power.
|
| When
is PRK the preferred choice of treatment |
•
When the cornea is too thin for Lasik.
• When a pre-existing problem is present on
the cornea, which can be eliminated with PRK and
result in better vision than LASIK.
• When there is a structural abnormality in
the cornea that makes LASIK unsafe.
• For low to moderate power myopia and astigmatism.
• After radial keratotomy. |
The
Procedure for PRK
You will be
awake for the entire procedure. |
•
You may be given anti-anxiety medication.
• You will have anesthetic drops in both eyes
so you will not feel anything
• A speculum is placed in the eye, to hold
the eyelids open, you can tell that they are there,
but you do not feel them. You will actually feel
like you are blinking normally.
• The surgeon will prepare the surface of
the eye by removing the top layer of cells.
• You just need to stare at a red dot while
the laser tracks your eye.
• You will hear a rapid clicking sound while
the laser is in action, and you may notice a smell
like burning hair.
• The surface of the eye is then cleaned,
and bandage contact lens is placed.
|
| What
are the risks? |
Risks
of PRK are minimal. There is a small chance, as
indicated in statistics above, that postoperative
vision may be dramatically better, but not equivalent
to 20/20 vision. A small number of patients may
have a weak pair of glasses that they use occasionally.
The only other significant risk is that of a slight
corneal "haze", which may reduce vision
after surgery, to less than 20/20. This occurs in
a very small percentage of cases and usually disappears
on its own in a 3-6 month period. However, it may
cause some halos around lights at night or symptoms
of glare in bright light. This haze or scarring
is more common when correcting higher levels of
myopia and is very rare for lower power. In general,
there is minimal restriction in activities after
PRK. Participation in contact sports and swimming
is possible. |
|
