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IntraLase & iLASIK :
Creating a LASIK Flap with
Precision
A newly developed technology
called IntraLase appears to
enhance the safety of LASIK
vision correction by using
laser energy instead of a
microkeratome, a cutting
tool with a metal blade used
in traditional LASIK
procedures.
In LASIK, the microkeratome
is used to cut a hinged flap
in the cornea. The flap gets
folded back, and an excimer
laser is used to remove (or
"ablate") some tissue from
the newly exposed surface.
Then the flap is put back in
place, resulting in a
reshaped cornea that
produces better vision.
With IntraLase, a special
laser is used instead of a
blade to create the flap.
Then the usual excimer laser
does the ablation.
So in the IntraLase
procedure, two different
lasers are used, which is
why LASIK surgeons sometimes
call it "bladeless" or
"all-laser" LASIK.
As in typical LASIK, the
flap then is replaced to
serve as a type of natural
"bandage" for healing.
Advanced Medical Optics
(AMO) in 2007 acquired
IntraLase, which was
integrated into the
company's CustomVue excimer
laser platform. The new
system now is marketed as
iLASIK.
Considering Complications:
Blade Versus Bladeless
While LASIK complications
are relatively rare, they
are sometimes associated
with the oscillating blade
used with traditional
microkeratomes. Metal blades
might create uneven flap
edges, resulting in abnormal
corneal surfaces and vision
defects such as irregular
astigmatism.
Metal blades also have been
associated with formation of
incomplete or improperly
formed "buttonhole" flaps
that can cause
vision-threatening scars.
Many eye surgeons report
these types of complications
are far less likely with
laser-created flaps.
As a replacement for
microkeratomes, IntraLase
creates flaps through
infrared laser energy that
inserts a precise pattern of
tiny, overlapping spaces
just below the corneal
surface. The IntraLase laser
operates at extremely high
speeds (pulses of one
quadrillionth of a second),
allowing tissue to be
targeted and divided at a
molecular level without heat
or impact to surrounding
tissue.
Studies indicate that
IntraLase is associated with
significantly fewer overall
LASIK complication rates.
Nevertheless, eye surgeons
recently have reported one
postoperative complication
of unusual light sensitivity
such as photophobia that
appears unique to the use of
the IntraLase in LASIK.
Usually patients are given
the choice of whether they
prefer LASIK flaps to be cut
with a blade or with the
more expensive laser
technology, but some
surgeons may prefer to use
only IntraLase and may
bundle that cost into their
overall LASIK fee.
The LASIK surgeon uses
computer software to guide
the IntraLase laser beam,
which applies a series of
tiny (3-micron-diameter)
bubbles within the central
layer of the cornea. The
resulting corneal flap is
created at a precise depth
and diameter pre-determined
by the surgeon.
As occurs with a mechanical
microkeratome, a small
section of tissue at one
edge of the flap is left
uncut, forming a hinge that
allows the surgeon to fold
back the flap so that the
cornea can be accessed and
reshaped for vision
correction.
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