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Every Cornea is Different
Every corneal flap is different, too. But
there are certain characteristics that every flap must have, including
precise diameter, centration and thickness, thereby setting the
stage for your doctor to perform an excellent Step Two.
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Traditionally, doctors have used a noisy mechanical
procedure to create the flap. In this method, the doctor cuts
across the cornea using a hand-held microkeratome with an oscillating
blade. Achieving accurate depth, flap thickness, and centration
on a curved cornea of varying dimension can be difficult with
a microkeratome. The precision of this step is highly dependent
upon the performance of the microkeratome device, which may be
unpredictable despite a high degree of surgeon skill.
Creating the Laser Flap
The INTRALASE® laser actually represents a breakthrough in
the field of ultrafast laser science. Generating light pulses
as short as one-quadrillionth of a second, femtosecond laser technology
has opened new fields of scientific study and provided the basis
of femtochemistry research that won the 1999 Nobel Prize in Chemistry.
The use of the femtosecond laser in the field of ophthalmology
was developed by a team of physicists, biomedical engineers and
ophthalmologists at the Center for Ultrafast Optical Sciences
and the Kellogg Eye Center of the University of Michigan.
The IntraLase ultrafast femtosecond laser is the first bladeless
laser technology for performing Step One of LASIK and the most
accurate technology for corneal flap creation available today.
The laser uses an infrared beam of light to precisely separate
tissue through a process called photodisruption. In this process,
the focused laser pulses divide material at the molecular level
without the transfer of heat or impact to the surrounding tissue.
• IntraLase creates the flap from below the
surface of the cornea, using an “inside-out” process.
• The silent beam of laser light is focused to a precise
point within the stroma (central layer of the cornea) where
each pulse of the laser creates a tiny 2- to 3-micron bubble
of carbon dioxide and water vapor.
• Thousands of these microscopic bubbles are precisely
positioned to define the flap’s dimensions, as well as
the location of the hinge.
• Bubbles are then stacked along the edge of the flap up
to the corneal surface to complete the flap.
• The process from start to finish takes approximately
45 seconds.
• The surgeon then lifts the flap to allow for treatment
by the excimer laser. When treatment is complete, the flap is
repositioned.
With IntraLase, your doctor can create a corneal flap of exact
diameter, depth, hinge location, centration, and overall architecture.
Such accuracy and precision are nearly impossible in a hand-held
blade.
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David V Leaming,
M.D.: Practice styles and preferences of American Society
of Cataract and Refractive Surgery (ASCRS) members—2003
survey. Journal of Cataract and Refractive Surgery April
2004; 30:892-900. |
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“It didn’t make sense to do custom LASIK, which involves
a more precise second step, without a better flap.”
Dan Durrie, M.D.
Overland Park, Kansas
IntraLase Flap Configuration:
• Uniform flap thickness
• Uniform flap bed
• Round flap with beveled edge for precise repositioning,
alignment, and seating of the flap.
In an industry survey, a majority of surgeons (52%) indicated
that the device they would prefer to create the corneal flap
is the IntraLase FS laser.*
Femtosecond lasers produce light pulses of one quadrillionth
of a second or one millionth of a nanosecond.
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