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What is the cornea? 
The cornea is the clear window
at the front of the eye that provides physical protection to the
eye and is the part of the eye's focusing power required for
sight.
Why may the cornea need to be replaced?
When the cornea is damaged by
injury or disease, scarring and inflammation can hinder the
passage of light and prevent vision. Under these circumstances,
it is necessary to replace the cornea in order to restore sight.
This is usually achieved by transplanting a donated human
cornea.
What is AlphaCor Artificial Cornea?
AlphaCor is a small, flexible
plastic disc that is designed to replace a scarred or diseased
cornea. The central part of AlphaCor is clear and acts a bit
like a lens, just like the natural cornea. The rim or skirt of
AlphaCor resembles a sponge and acts to secure the device into
place by allowing the patient's own tissue to grow into it and
hold it in place.
Why do we need AlphaCor?
While a donated human graft
can be very successful, there are occasions when they fail. In
these cases the likelihood of further transplants being
successful is reduced. In some instances the chance of failure
is so high, a further graft would not even be attempted. Thus,
there are many patients who are currently considered untreatable
by means of a conventional corneal transplant. In addition,
there are some parts of the world without an adequate Eye
Banking System and some religious denominations discourage the
use of donor tissue.
What does the surgery involve?
The surgery itself is similar
to the implantation of a donor cornea, in that part of the
cornea is removed and the AlphaCor put in its place. A pocket is
made within the plane of the scarred cornea and this is where
the AlphaCor is implanted. In many cases, the operation is
completed by the formation of a flap of tissue from the
conjunctiva (the outer layer of the 'white' of the eye), which
is used to cover the surface of the front of the eye. This means
that the eye does not look normal after the operation, but it is
important because it allows the artificial cornea to heal into
place under the protection of this natural bandage. After three
months, the flap of tissue and a thin layer of cornea are
removed, exposing the AlphaCor and allowing light to enter the
eye.
What side effects or complications may occur?
All surgery is associated with
the risk of complications. This procedure involves all the same
risks and potential complications of a conventional corneal
graft, which, although uncommon, include infection, glaucoma and
retinal detachment. All accredited surgeons have access to the
latest clinical data so would be able to advise prospective
patients.
How long will it last?
AlphaCor has been implanted in
some patients for more than five years, however, it is difficult
to predict how long AlphaCor will last in individual patients.
All AlphaCor recipients should remain under close review, so
that any complications are detected and managed appropriately.
If necessary, AlphaCor replacement is possible and can be done
either with another implant or with donor corneal tissue.
How well will I be able to see through it?
AlphaCor is made to act in a
similar manner to a natural cornea. It is difficult to predict
how good vision will be in an individual patient. The patients
who have received an AlphaCor have had outcomes varying from
little improvement in vision to regaining the ability to read.
The visual potential of an eye depends upon the health of all
parts of the eye; someone with glaucoma or retinal problems, for
example, might find that their vision was still limited, even if
the artificial cornea itself worked perfectly.
Following the second stage of the procedure, vision can be improved for AlphaCor recipients using the same techniques that are used to correct vision in people with normal corneas. For a patient with good vision in the other eye, it is unlikely that an eye with the AlphaCor would be better than its fellow eye, but might give useful additional sight. However, if the other eye was of little use, the AlphaCor eye might well become the one that was depended upon for useful vision. Could I end up "worse off" after having an AlphaCor implanted?
The clinicians who have been
involved in testing the AlphaCor don't consider that the risks
associated with AlphaCor are substantially greater than those
associated with a normal graft. However, as with any major
surgery the potential for complications does exist, and this
should be discussed with your specialist. A unique feature of
AlphaCor is its ability to be reversed. Because of the size and
design of the device, it can be removed at any time and a donor
graft can be implanted thus, returning the patient back to their
original post-operative state.
Addition Technology is dedicated to ensuring all surgeons implanting the AlphaCor are fully informed of known risk factors and are familiar with the most appropriate management regimes. In order to minimize risks, patients should only be offered surgery after detailed ocular assessment and elimination of any extra risk factors. All possible precautions should be taken before, during and after the procedure. What would the follow-up requirements involve?
Patients with AlphaCor will
require regular checkups. In routine cases, patients are not
required to take oral steroids but use topical medications on a
continuous basis to minimize the risk of complications. Patients
will be advised of sensible precautions they should take to
minimize the risks of injury or infection. Occasionally, follow
up procedures may be required.
How do I get an AlphaCor?
Only Accredited Surgeons who have
attended the AlphaCor accreditation program are able to implant
the AlphaCor.
Patients should discuss their suitability for an AlphaCor with their local ophthalmologist before seeing an AlphaCor accredited surgeon. |
AlphaCor
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