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WHAT IS LASIK
LASIK stands for
Laser-Assisted In Situ Keratomileusis
(ker-a-toe-my-loosis) and is a two-step procedure
that reshapes your cornea to allow light to
properly focus on the retina. The first step
in the procedure is the making of the flap and the
second step is laser ablation to reshape the
cornea. At Lasik Eye Turkey , we use
the Intralase 60kHz for making the flap and VISX
Star 4 Custom Wavefront with Iris Registration for
the reshaping of cornea to correct the patient’s
vision. A description of the LASIK procedure
follows.
LASIK eye surgery generally requires twenty (20)
minutes of operating room time, but the actual
duration may vary according to the type and amount
of correction needed. A mild sedative,
Ativan, is usually taken to help you relax just
prior to the procedure. During LASIK eye
surgery, you will be lying on the laser bed
or reclining chair and your eyelids will be held
open with a device called a lid speculum. You will be asked to focus on a special fixation
light. You will be given eye drops to numb
your eyes in a very similar way to the numbing of
the eyes with cataract surgery.
The Intralase 60kHz (femtosecond laser) is used
to create a flap of tissue in the cornea.
This flap is then lifted like the cover of a book
to expose the tissue just below the cornea's
surface. There is a hinge in the superior
cornea that allows accurate repositioning after
the laser procedure is completed.
The excimer laser (VISX Star 4 with custom
wavefront and iris registration) is used to
reshape the cornea by removing an ultra-thin
amount of the exposed tissue of the cornea. A computer inside the excimer laser is used to
control how much corneal tissue is removed. The flap is put back into position and antibiotic
drops are applied.
You must wear protective eye shields for the
first night to prevent rubbing your eyes, and
you will be required to use antibiotic and
anti-inflammatory eye drops on a regular basis for
a few weeks after LASIK eye surgery. You may
need to use lubrication eye drops for several
weeks after your LASIK eye surgery.
LASIK eye surgery is performed on an outpatient
basis at Carolina Cornea and Laser Center. You
will be able to go home approximately 30 minutes
after your LASIK eye surgery, but you will need to
arrange for someone to drive you home after your
surgery. The typical patient is able to go
back to work the next day and is able to drive him
or herself to the office for follow-up. Follow-up visits are one day, one week, one month,
and 6 months.
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The LASIK
Procedure
The LASIK procedure is performed in three steps:
- First, a microkeratome is used
to make a thin flap in the outer layer of the cornea without
damaging the surface. The flap is temporarily folded back.
- The surgeon then uses the
laser to reshape the cornea, improving the way light is
focused on the retina and thus producing clearer vision. The
laser is so accurate that it can be used to sculpt ones name
on a human hair. The total depth of sculpting needed to
provide naturally crisp vision is typically less than
one-fourth the thickness of a human hair.
- Finally, the corneal flap is
returned to position and heals in place. Because the reshaped
portion of the cornea is protected from exposure to the air by
the repositioned corneal flap, patients report virtually no
discomfort with LASIK .
Normally, the entire procedure
lasts less than ten minutes, with patients typically experiencing
an improvement in their vision immediately following the
procedure.
Some discount providers perform
LASIK using lasers that are not approved by the FDA specifically
for the LASIK procedure. These lasers have not gone through the
clinical trials and evaluation the FDA requires in order to
certify these devices as safe and effective for this use.
What is Wavefront?
Also known as Custom LASIK or
Custom Wavefront LASIK, Wavefront guided treatment replaces 'the
one treatment fits all' with a procedure that is
tailored to the precise optics of the eye. Whilst standard
laser eye treatment (without Wavefront guidance) gives very high
quality results for the majority of patients, many peoples' eyes
are not 'standard'.
Everybody who comes to
Laser Eye Turkey has
their eyes measured, not just for prescription strength, but to
assess their optical performance in terms of quality of vision
when the prescription is in place.
Glasses lenses are standard
shapes and their optical performance is made to fit the average
population as a whole, whilst the laser improves individual
physical and optical characteristics precisely for each eye.
Patients who are suitable for Wavefront treatment
can achieve better results than wearing glasses or contat
lenses can.
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Wavefront Customised Laser Beam |
Wavefront and Night Time Vision
Wavefront is a big advantage to those with large pupils and
poor night time vision. The optical performance of the eye is
measured at each and every place on the cornea, including the
part which is used when the pupil is large. Laser treatment is
then programmed to each tiny part of the corneal surface so that
every area of the cornea gets the optimised dosage. Contrast
sensitivity in low lighting levels is increased and the risk of
developing night time halos and glare is greatly decreased.
Wavefront Results
About half of patients should benefit significantly with
sharper vision from Wavefront treatment. Our experienced
doctors will cover this in detail during the consultation.
Our published
statistics are based on 7,000 standard treatments during
2004 and 2005. These will see substantial improvement when
Wavefront becomes the norm for suitable patients, both in the
number who achieve 20:20 without glasses and safety as
measured by change in visual sharpness.
We use the most
advanced diagnostic machine available in the marketplace -
the Nidek OPD (Optical Path Difference) device.
The Nidek OPD
measures the progress of 8,000 waves of light as they pass
through different parts of the eye and is the best
available technology in its field in the world.
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When the light rays are
reflected back from the eye into the Nidek OPD, it
digitally analyses the differences in the wave paths to
what they should be for perfect sight.
These 8,000 data points
are used to program the laser to correct each part of the
eye (corneal surface). The aim is to shape each tiny
section of the cornea to the correct focusing power,
resulting in the sum total of the cornea focusing to be
perfect and to be as near distortion free as is possible
(click image to enlarge).
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Iris recognition
The Nidek OPD is very precise in locking onto the eye to be able
to digitally map tiny sections of the cornea and then instruct
the laser to target the same area to remove any tiny
imperfections. In this way the laser is accurately given
instructions to laser the intended area on the cornea.
High Speed Tracking
Optimax uses the fastest tracker of any make of laser used in
eye treatment. During treatment the tracker on the laser videos
the image of the iris 200 times per second (200 htz) and matches
it to the data it is given from the Nidek OPD. If you move your
eye during treatment the laser follows it precisely.
Tissue Sparing
A benefit of Wavefront is that only precise amounts of tissue
are removed from the parts of the cornea that need it. By
getting treatment dosage closer to the actual need of each
part of the cornea, less tissue is removed. This improves long
term safety by maintaining the maximum structural strength of
the eye following treatment.
Optimised and Customised Wavefront (OATZ/CATZ)
OATZ (Optimised Aspheric Treatment Zone - Aspheric) means
‘not spherical/round’. Optimised Wavefront is for those with
normal corneal surfaces but whose general shape of the eye
is not optically round enough for perfect focusing.
CATZ means Customised Aspheric Treatment Zone. Customised
Wavefront is used for patients whose eyes have undulations on
the corneal surface that require individual removal and who will
benefit from Aspheric Treatment.
All other Wavefront treatment
details are the same as for LASIK
and Epi-LASEK
laser eye surgery.
Wavefront Charges
Additional equipment and extra doctors time are required for
the extensive calculations required to provide Wavefront
treatment. Optimax charges a modest £295 per
eye for this service in addition to the normal treatment cost
for LASIK or Epi-LASEK laser eye surgery.
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