Lasers
can be used for many purposes from correcting refractive conditions such
as myopia (nearsightedness), hyperopia (farsightedness) and astigmatism
(warped vision), to therapeutic purposes in diabetic eye disease and macular
degeneration. Different lasers are used for each procedure and different
doctors specialize in each type of treatment.
If
laser surgery is suitable for you, we will refer you to the appropriate
specialist for treatment. We work with only the best laser centers, like
TLCand
Maloney
Vision
Institute
. Pre- and post-op care will
be provided in our office and, in the case of refractive surgery (PRK or
LASIK) we will work closely with the surgeon to design the procedure for
the most useful visual outcome for your individual situation.
There
are other refractive surgeries besides laser. The Visian
ICL is an
implanatable lens which can correct extremely high prescriptions--and with
optical clarity which can exceed laser vision correction. For those over
age 40, the Crystalens
can return some of the near focusing ability lost with accumulated birthdays.
Photo refractive
Keratectomy (PRK) is used to sculpt the cornea to a new, flatter, curvature
thus reducing myopia. Up to 6.00 diopters of myopia can be corrected in
this way.
The
laser works on the front surface of the eye called the cornea. The cornea
has 5 layers: epithelium, Bowman's membrane, stroma, Descemet's membrane,
and endothelium from front to back. The epithelium, Bowman's membrane and
part of the stroma are removed by the laser. The laser is computer controlled
to remove the precise amount of tissue as determined in our pre-operative
exam.
A bandage
contact lens is then placed on the cornea while the epithelium grows back
over the new surface. Bowman's membrane does not regenerate.
Eye
drops are used to provide comfort during the 4 days or so it takes the
epithelium to grow back. At this time the bandage contact lens is removed.
Anti-inflammatory drops are used for several months as the healing process
stabilizes. Although vision is usually noticeably improved within 48 hours,
complete stabilization may take from 3 to 6 months. We will see you regularly
during this period.
Laser in-situ
Keratomileusis (LASIK) also uses a laser to reshape the cornea. First a
cap is created with an automated microkeratome and the first 2 layers of
the cornea, the epithelium and Bowman's membrane, are lifted out of the
way. The laser then reshapes the stroma, the cap is replaced and adheres
without sutures. As with PRK the laser is computer controlled to remove
the appropriate amount of tissue as indicated by our pre-operative exam.
The
advantages to LASIK are faster recovery of vision, better initial comfort,
and no loss of the first 2 layers of the cornea. Myopia up to 18.00 diopters
(although there may be better options for the higher corrections), astigmatism
up to 6.00 diopters and hyperopia up to 6.00 diopters can be corrected.
Eye drops are usually only indicated for the first week following surgery.
Vision may take 1 to 3 months to stabilize, but most patients are able
to pass a drivers vision test within a day or two!
Radial
keratotomy (RK) is an incisional (not laser) procedure to correct myopia.
A similar procedure can be used to correct astigmatism. RK is more surgeon
dependent on the outcome since a hand held scalpel is used. Radial cuts
are made in the peripheral cornea which weakens this area allowing the
cornea to flatten. RK is dropping in popularity as lasers have come about.
A common
misconception is that lasers are used for cataract surgery. This is not
the case. A small incision is made with a scalpel through or just
behind the cornea. The lens inside the eye is then broken up with ultra-sound
and removed with suction. An artificial lens is then placed in position.
Cataract surgery is an out patient procedure today.
If
clouding returns to the lens capsule after the initial surgery, then a
secondary procedure can be performed using a laser.
Refractive
surgery is undergoing many changes. We now have available implantable
contact lenses which leave the natural cornea intact. Very strong prescriptions
can be done. Let us know if you would like to be considered for this procedure.
A new
procedure called corneal molding is in development where a small injection
of an enzyme into the cornea relaxes the bonds which hold its shape. A
corneal mold, similar to a contact lens, is then placed on the eye
while the corneal bonds re-form to the mold. After the mold is removed
you have a newly shaped cornea and improved vision. The mold is computer
designed and can correct virtually any refractive condition without surgery!
This would be like permanent CRT .
Everybody
over age 40 experiences presbyopia, the loss of ability to change focus
from distance to near and back again. Clinical trials are now underway
for PressVIEWTM Scleral
Implants (PSI) to restore this focusing ability! If you would like to be
included in the study (it would still cost you about $3,000 for one eye),
give us a call.
Please submit any questions or comments to: wbarrod<at>drbarr.com
