We are frequently asked
to describe the method in which we fabricate plastic
artificial eyes. This is our attempt to do this in as
brief and concise manner as possible.
We fit
plastic artificial eyes by a very special Modified
Impression Method, perfected and improved by us since
1953. It results in a prosthesis with the best possible
appearance and with most comfort. The superiority of this
method makes it possible for surgeons to use the latest,
sophisticated implants in the eye removal surgery knowing
it also offers the greatest safety to the eye socket
tissues. It also offers the best transference of movement
from whatever is available from the eye socket. This may
be only minimal if there is no implant, or moderate to
excellent with various types of implants.
We require that adequate healing take place before
fitting with the plastic eye. Schedule permitting, we
will fit the prosthesis at six to eight weeks after
surgery.
The patient fills out a registration form which is
the beginning of a record similar to any kept by a
practitioner.
An impression of the shape of the space in the eye
socket is made with alginate, which sets up within 1
minute without discomfort to the patient, until it has a
consistency similar to the white of a hard boiled egg.
After removal from the eye socket, a two piece mold is
made around it with dental stone, a material very much
like Plaster of Paris. The impression material is removed
and a molten hard type of wax is poured into the mold and
allowed to cool and harden. After opening the mold, this
wax piece constitutes a pattern for the artificial eye
which can be changed in shape on the front surface and
edges to improve the appearance and comfort of the piece
by removing or adding wax where desired and the posterior
surface irregularities are softened but retained for
comfort and motility.
A plastic piece similar to the pupil, iris and
cornea of the front of the eye, as near the color of the
patient's living eye as possible, is chosen and this is
built into the wax pattern. It can be removed and
replaced in a different position on the pattern in order
to give the proper effect of direction of gaze and
vertical and horizontal positions as well as to give the
desired prominence to the artificial eye and to create
the proper opening of the eyelids. This part of the
procedure usually takes several hours during which the
patient must remain available at 10-20 minute intervals
for trial fittings.
When all the improvements possible have been made
in the wax pattern, a new, final mold of dental stone is
made around it in a strong bronze flask. The wax pattern
is removed, and the pupil-iris-cornea piece is placed
back in the mold exactly where it had been in the wax
pattern. A dough of white plastic (acrylic) is packed in
the mold and processed by heat and pressure until it is
cured and hardened. This, then, constitutes the beginning
of the final plastic eye.
A thin layer of plastic is ground, filed and sanded
from the front surface of the eye so that, after tinting
with color and placement of red cotton threads to
simulate blood vessels, a protective layer of transparent
acrylic can be cast over the front surface to bring the
form back to exactly the shape of the final wax pattern.
The coloring of the eye is done with the greatest
care to match the companion eye and to present an
appearance of living tissue. This is done by a method
devised by us in October, 1976 and used exclusively by us
and a few of our former apprentices. The patient must be
present for this part of the work for perhaps three or
more hours. During the painting, the prosthesis can be
made to have its final shape and to look as if completely
finished. It can be placed in the patient's eye socket to
be judged with all illusions present, then removed and
the coloring altered. This step can be repeated until the
coloring is fully satisfactory.
When the color is judged to be correct, the eye is
returned to the final mold and a layer of transparent
acrylic is cured on its front surface to protect the
color during polishing and wearing.
The finished, highly polished prosthesis is placed
in the eye socket and judged in all respects. If it is
not right in every way, changes can be made until it is
not possible to improve it further.
This whole procedure takes 2 days ordinarily. If
the eye socket is a very difficult one to fit, it might
take 1 or 2 days more. While most other eye fitters take
less time, we find that we can produce far superior
prostheses, in all respects, by using this time
consuming, painstaking method.
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