Lasik and other Laser Vision Procedures
•
LASIK
•
All Laser LASIK” (Bladeless)
•
PRK
•
Wavefront-guided (Custom)
LASIK and PRK
•
LASEK
•
EpiLasik
Lens
Implants
•
RLE (Refractive Lensectomy
) or CLE (Clear Lens Lensectomy)
•
Phakic Implants
•
Toric Implants
•
Cataract Implants
Other Refractive Surgery Procedures
•
CK (Conductive
Keratoplasty)
•
Limbal Relaxing
Incisions or Arcuate Incisions
LASIK
(Laser In Situ Keratomileusis)
Refractive
Surgery Treatment for:
•
Nearsightedness
•
Farsightedness
•
Astigmatism
•
Presbyopia (Monovision)
LASIK
is the most common refractive surgical procedure worldwide and
nearly one million procedures
are performed annually in the United State. LASIK surgery consists
of the creation of a corneal
flap with either an IntraLase (femtosecond laser) or a surgical
blade (in medical terms, a “mechanical microkeratome”).
The flap is gently folded
back and the excimer laser resurfaces the cornea to a new shape.
LASIK has been
approved by the FDA to correct nearsightedness (Myopia), farsightedness
(Hyperopia),
astigmatism (either combined with nearsightedness or farsightedness),
and
Presbyopia (where LASIK is performed on one eye to create monovision).
“All
Laser" LASIK (Bladeless)
"All
laser" or bladeless LASIK is performed by using the IntraLase
Pulsion™ FS Laser system
and is the only all-laser alternative to the mechanical microkeratome
(surgical blade).
During an "all laser" LASIK procedure, the IntraLase
laser creates a corneal flap of aprecise
thickness and diameter with a lower suction level than a standard
precise microkeratome
without
using a blade. Bladeless LASIK offers laser eye surgeons optimal
precision and total
control, which makes creating a flap safer than standard
microkeratomes using
higher suction and blades.
All
Laser LASIK enables patients to choose laser vision correction
surgery with more confidence.
PRK
(PhotoRefractive Keratectomy)
Refractive
Surgery Treatment for:
•
Nearsightedness (Myopia)
•
Farsightedness (Hyperopia)
•
Astigmatism
•
Presbyopia (Monovision)
PRK
(PhotoRefractive Keratectomy) involves reshaping the curvature
of the cornea with an
excimer laser to correct nearsightedness or farsightedness with
or without astigmatism.
PRK was the first procedure approved by the FDA in 1996. It is
performed by
removing the surface layer of the cornea (epithelium is the “skin”
of the eye) and applying
the laser directly to the layers beneath the surface. It is essentially
LASIK without the creation of a LASIK flap. PRK generally produces
results similar to LASIK ; however, the patient usually experiences
more discomfort and has a slower recovery of vision than
in LASIK, since it takes several days for the epithelium to grow
back. PRK has been approved
by the FDA to correct nearsightedness (Myopia), farsightedness
(Hyperopia), astigmatism
(either combined with nearsightedness or farsightedness). Monovision
is also
an option with PRK, for either nearsighted, farsighted or astigmatic
eyes as well as
with Presbyopia, although Monovision PRK represents an "off
label" use of thelasers
since it is not FDA-approved.
Wavefront-guided
(Custom) LASIK and PRK
The
Wavefront-Guided procedure is used for LASIK and PRK. All of the
Wavefront-guided procedures
were approved by the FDA for LASIK. They can be utilized with
PRK, but this
represents an “off label” use of the laser.
Procedure
is used with LASIK and PRK in treatment of:
•
Nearsightedness
•
Farsightedness
•
Astigmatism
•
Presbyopia (Monovision)
One
of the most exciting advances in the field of refractive surgery
involves the application
of Wavefront testing to the human eye. The basis of Wavefront
testing is from
the field of adaptive optics, used for years by astronomers to
build better lens systems
for improving the optics of telescopes.
The
human eye has two bread categories of aberrations, lower order
and higher order. Lower
order aberrations represent the patient’s prescription for
glasses. There are many
higher order aberrations but the two most important
ones for potential LASIK patients
are
spherical aberration and coma. When these two aberrations are
increased above
preoperative
levels, patients may notice more problems with the quality of
their night
vision
and be more aware of halos, starbursts, flare, and glare.
Conventional
laser eye surgery (LASIK and PRK) for years was excellent at reducing
or eliminating
the lower order aberrations and most patients obtained satisfactory
uncorrected
vision, usually near 20/20. However, conventional laser eye surgery
procedures
like LASIK and PRK have often increased the degree of higher order
aberrations,
which accounted for the possible increased likelihood of night
vision problems.
Wavefront-based
laser eye surgery measures the amount of both lower and higher
order aberrations.
This information is then used by the excimer laser system for
both LASIK
and
PRK in an attempt to either reduce or at least minimize the increase
of higher
order aberrations. All of the FDA approved laser systems for LASIK
and PRK now
offer this
type of treatment, so that each patient’s optical system
is measured more
accurately
than ever before, producing in effect a unique “finger print”
of their pre-operative
visual problems. This truly customized treatment plan is then
implemented
in the laser eye surgery (LASIK, PRK) for each patient.
This
Wavefront fingerprint enables the laser eye surgeon to program
the laser in order to
obtain the best results for the laser eye surgery that is best
for you. By using Waverfront
testing, there is a possibility that your existing higher order
aberrations may not
increase at all, and some patients report that they can see even
better than they did
with glasses or contact lenses. This is known as a "gain
in best spectacle corrected visual
acuity". The FDA studies of Wavefront-based treatments in
LASIK, PRK and other
laser eye procedures have improved the chance of obtaining 20/20
vision or better and
have decreased the chances of significant night vision problems
(due to higher order aberrations).
EpiLasik
EpiLasik
a form of PRK where the epithelim is removed with a mechanical
microkeratome and the underlying surface is then treated with
an excimer laser.
LASEK
LASEK
(Laser-Assisted Sub-Epithelial Keratectomy) is a form of PRK where
the epithelium is loosened, usually with alcohol, and either reflected
like a LASIK flap and replaced after the excimer laser is applied
to reshape the cornea. At times the epithelium is simple discarded
and allowed to regenerate as it does in standard PRK surgery.
Lens
Implants
RLE
(Refractive Lensectomy ) or CLE (Clear Lensectomy)
Refractive
Surgery Treatment for:
•
Farsightedness (Hyperopia)- Moderate to high
levels
• Nearsightedness (Myopia)- Can possibly
be used for people with a high degree of nearsightedness
where LASIK or Phakic implants are not suitable procedures.
• Astigmatism
RLE
(Refractive Lensectomy ) or CLE (Clear Lensectomy) is a refractive
surgery procedure
where the eye surgeon removes the internal lens of the eye (as
in a cataract operation)
and inserts a lens implant of a stronger power inside the eye.
The refractive surgeon
will calculate the power of the replacement lens implant through
special measurements
of the length and curvature of the eye, which are then entered
into a special
computer formula.
Phakic
Implants
Refractive
Surgery Treatment for:
•
Extreme Nearsightedness (Myopia)
•
Astigmatism (FDA approval expected in the near
future)
Phakic
Implants are intraocular lens implants (inside the eye rather
than on the surface of
the eye like contact lenses) surgically placed inside the eye
in front of the eye’s natural
lens by a refractive eye surgeon. Phakic Implants are used to
correct higher amounts
of nearsightedness (Myopia). Because this refractive surgery
procedure is performed inside the eye (as opposed to a laser vision
proceudre that is performed on the surface of theeye),
the risks are slightly higher. Phakic Implants are utilized for
higher amounts of nearsightedness (Myopia) usually above -8.00
D to -10.00 D in an eye, which is often not correctable by laser
eye surgery. Phakic Implants
can also be used in cases with lower amounts of myopia if laser
eye surgery is
contraindicated because the cornea is too thin or abnormally shaped.
At present, these
implants do not correct astigmatism but FDA approval is expected
in the near
future.
Two Phakic implants are approved by the FDA. The Visian from STAAR
surgical and
the Verisyse from Advanced Medical Optics (AMO). More details
about these implants are available on the company web sites. For
STAAR, please visit www.visianinfo.com and for Verisyse please
visit, www.visioninfocus.com.
Toric
Implants
Refractive
Surgery Treatment for:
•
Astigmatism for Nearsighted (Myopic) Eyes
Toric
Implants have the astigmatism correction incorporated in the power
of the implant
and
they are available for some eyes undergoing Refractive Lensectomy
(RLE or
CLE). This
refractive medical procedure should be available in late 2008
for Phakic Implants
for
Nearsightedness (Myopia).
Cataract
Implants
Refractive
Surgery Treatment for:
•
Cataracts
Cataract
surgery is performed under local anesthesia on an out-patient
basis. The surgery
is accomplished in 15 to 30 minutes, utilizing a very small incision,
usually without
sutures. The cataract is broken up (emulsified) with an ultrasonic
vibrating needle
and the liquefied cataract is aspirated through this same needle.
The cataractous
lens is then replaced with a lens implant designed to replace
the natural lens.
This new lens can usually reduce or eliminate the previous need
for glasses in near
sighted or farsighted patients so they may no longer require glasses
for distance. Lens
implants can also create a monovision situation similar to the
monovision form LASIK
or PRK. More recently, the FDA has approved 3 “presbyopia”
correcting implants
which can allow the eye to see clearly for both far and near.
These lenses include
multi-focal lenses like the the Restor by Alcon and the Rezoom
by Advanced Medical
Optics (AMO) and the the Crytalens from Eyeonics, which is designed
to change focus by flexing
in the eye. You can learn more about these lenses by visiting
the company web sites.
For the Restor lens, please see www.acrysofrestor.com. For the
Rezoom lens, please
see www.rezoomiol.com.
For more information about the Crystalens, please see
www.crystalens.com.
Other
Refractive Surgery Procedures
CK
(Conductive Keratoplasty)
Refractive
Surgery Treatment for:
•
Mild Farsightedness (Hyperopia)
•
Presbyopia (in normal sighted eyes and in patients
who are now normal sighted following
laser surgery years earlier but who are now Presbyopic).
Nearvision
CK (Conductive Keratoplasty) is capable of correcting low amounts
of farsightedness
(Hyperopia) or Presbyopia. The procedure is very safe and easy
to perform.
CK consists of applying a special probe with a very fine, short
tip. The tip is typically
applied to 8 spots on the peripheral cornea, delivering a less
than one second burst
of radio frequency energy to the eye which steepens the central
corneal curvature.
Conductive Keratoplasty is the only FDA-approved procedure for
the correction
of Presbyopia.
NearVision
CK (Conductive Keratoplasy) can change how the eye focuses light
by reshaping
the cornea to improve near vision. It uses a controlled release
of radiofrequency
(RF) energy to shrink corneal tissue, which steepens the cornea.
This steepening
creates a safe and predictable modification to the topographical
(surface) curvature
of the cornea for the temporary reduction of Presbyopic and mild
hyperopic symptoms.
CK is usually performed on only one eye and is designed to reduce
the dependence
on reading glasses. As the patient ages, the effect of the CK
can lessen,
and the procedure may need to be repeated to maintain best reading
vision.
Limbal
Relaxing Incisions or Arcuate Incisions
Refractive
Surgery Treatment for:
•
Astigmatism
Incisions
in the cornea are accomplished with a special diamond scalpel
where the blade
depth is set by a micrometer as determined by the corneal thickness.
These incisions
are placed in the steep or more curved portion of the cornea in
order to reduce the
curvature of the cornea and thereby potentially reduce astigmatism.
Limbal relaxing incisions are placed
just inside the white portion of the eye (sclera). Arcuate incisions
are placed in
the more central clear portion of the cornea.
To
find a vision correction expert surgeon who has qualified to be
listed at Trusted LASIK surgeons in another area, please visit:
Find
a Trusted LASIK Eye Surgeon
The
screening process and standards used by Trusted LASIK Surgeons,
can be found at:
How
Are Lasik Eye Surgeons Qualified at TLS