| What
is lamellar keratoplasty
Lamellar keratoplasty is the removal and replacement of
less than the total thickness of the cornea. The deeper part of the stroma, Descemet's membrane, and the endothelium are not removed; this is
the difference between lamellar keratoplasty and penetrating keratoplasty
(corneal graft surgery), in which the entire thickness of the corneal is
replaced.
Lamellar keratoplasty can be useful in treating corneal dystrophies
in two situations.
1. It is sometimes used when the corneal dystrophy changes are
located in the anterior stroma or when there are surface
irregularities. Examples of these conditions are Reis-Buckler's
corneal dystrophy and sometimes lattice corneal dystrophy.
2. A lamellar graft might be used to treat a thin and abnormally
shaped cornea. An example of this is keratoconus,
in which extensive thinning can occur in the central cornea; this thinning
can lead to a cone-like bulging forward of the cornea. A lamellar
keratoplasty can be performed to correct this abnormal shape by restoring
normal thickness to the cornea. Lamellar keratoplasty is not
performed on patients who have deeper stromal dystrophies or endothelial
dystrophies.
The operation
 In a lamellar keratoplasty, the cornea is not completely
cut through during surgery. A
trephine (an instrument that works
like a cookie cutter) is used to mark the area of your
cornea that is to
be removed. Another instrument, like a spatula, then cuts underneath
the diseased layer of tissue and removes it, leaving the deeper corneal
layers in place. The surgeon makes a partial thickness graft from a
donor cornea in a similar fashion. This graft is inserted into the
opening made in your cornea and sewn into place. These steps are
shown in below. The suture stays in place for months and can be
easily removed when necessary.
a) The ophthalmologist removes abnormal portions of the diseased
cornea but leaves the deeper layers of the cornea in place.
b) Donor tissue of similar size and shape s inserted into the
opening and sutured into place.
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Chances of Success
Since the cornea is not cut through completely, there is
less risk of infection inside your eye. There is also a smaller risk
that your body will reject the graft. A lamellar keratoplasty heals
more quickly than a penetrating keratoplasty.
Generally speaking, visual acuity is not quite as good
after lamellar keratoplasty as after a penetrating keratoplasty.
Also, a lamellar keratoplasty is technically more difficult to do than a
penetrating keratoplasty. Occasionally at the time of surgery the
cornea is cut completely through. If this occurs, it might be
necessary to convert the operation to a penetrating keratoplasty. In
either instance, the surgery has an excellent chance of restoring good
vision.
Why are regular medical eye examinations
important for everyone?
Eye disease can occur at any age. Many eye diseases
do not cause symptoms until the disease has done damage. Since most
blindness is preventable if diagnosed and treated early, regular medical
examinations by an ophthalmologist are very important. If you
are experience any optical difficulties, or just need a routine eye exam,
please make an appointment to see Dr. Cano or Dr. Manning.
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