| The astigmatic
keratotomy (AK) is used to reduce severe astigmatism
of approximately 3 diopter or higher.
What is astigmatism?
As discussed in the chapter Refractive Errors (Astigmatism),
the surface of the cornea normally is curved evenly like the surface
of a ball. In case of astigmatism, the curvature is stronger in one
direction than in the other, so that images appear distorted. The surface
resembles that of an egg or a football more than that of a round ball.
What happens
during the AK procedure?
For the AK procedure, an arch-shaped deep incision (approximately 80%
of the thickness of the cornea) is placed in the axis of the strongest
curvature on the periphery of the cornea using a special diamond blade
or a custom-made single-use blade. This incision relaxes the corneal
tissue in the axis and results in a reduction of the curvature and thereby
in a reduction of the astigmatism.
Typical course
of an AK procedure and recovery after the surgery
The astigmatic keratotomy is an outpatient procedure. Prior to surgery,
you will be offered a relaxant. The eye, which is to be treated, is
then anesthetized locally with eye drops so that you will not feel any
discomfort during surgery. For the surgery itself, which only lasts
a few minutes, your eye is fixated with light pressure by a special
ring-shaped device. The procedure is painless.
After the surgery, the eye is covered with a clear bandage, which you
may remove a few hours afterwards. It is possible that a light foreign
body sensation or light discomfort may occur for a few hours following
the AK procedure.
A reduction of the astigmatism can be observed as early as the day
after surgery. However, it takes a few weeks until the result is stabilized.
Usually, new eyeglasses have to be prescribed a few days after the surgery
because the astigmatism has been reduced but not eliminated altogether.
You will receive eye drops, which have to be applied for several days
after surgery, and you will generally be able to resume work within
a few days after the procedure.
Treatment costs
The treatment costs are not covered by public or private health insurances.
This fact also applies in cases of documented intolerance to eyeglasses
or contact lenses. Currently, the costs for the preoperative and postoperative
exams generally are to be paid by the patient himself as well and are
calculated in accordance with the German coding system for the calculation
of medical services (Gebührenordnung für Ärzte –
GOÄ).
Please feel free to inquire about
the costs for an astigmatic keratotomy.
When is the
AK procedure used?
The AK procedure is indicated for the
reduction for severe astigmatism, although in most cases it cannot be
corrected entirely. Thus, the AK procedure is usually performed in combination
with a later second procedure such as LASIK.
In a typical scenario, an astigmatism is reduced with the AK and eliminated
altogether with the LASIK procedure about 3 months later.
Which problems
can occur?
After an astigmatic keratotomy, your vision without eyeglasses may
possibly get worse at first, especially in cases of a combination of
farsightedness and astigmatism.
Good vision without eyeglasses will then be achieved after a second
procedure such as the LASIK procedure is performed. The vision you can
achieve with eyeglasses will be better after the operation than before,
because part of the astigmatism has been eliminated. Furthermore, it
is likely that a new prescription for eyeglasses is required before
operating a motor vehicle.
Although severe side effects are not likely, they cannot be excluded
completely. In some cases, an irregular astigmatism may occur. In extremely
rare cases, a perforation of the eye may occur because the incision
was placed too deep.
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