How a Prosthetic Eye is Made
We require that adequate healing take place before fitting. Schedule permitting, we fit the prosthesis at six to eight weeks after surgery.
Using alginate, we take an impression of the eye socket (photo 1).
Initially, the material has a consistency similar to the white of a hard-boiled egg. With no discomfort to the patient, the alginate sets up in one to two minutes.
After removal from the socket, the impression is encased in dental stone, which is very similar to plaster of paris. The impression material is then removed from the mold and molten wax is poured into the mold. This is allowed to cool and harden. What we obtain is a wax piece that constitutes a model for the artificial eye. The wax allows us to make changes for comfort as well as opening eyelids to match the companion eye.
An iris button, similar to the pupil, iris, and cornea of the front of the eye is chosen and built into the wax model (photo 2).
This can be adjusted in order to give the proper direction of gaze. this portion of the proceedings usually takes two hours with the patient available for trial fittings so as to give the desired prominence to the artificial eye and create the proper opening and contour of the eyelids.
When satisfied with the wax model, we make a final mold of dental stone around it in a fiberglass flask (photo 3).
The model is then removed and after placing the iris button back in the mold exactly in the same position, we pack a dough of white plastic into the mold and process it by heated water bath until it has cured. This is the beginning of the final prosthesis.
A thin layer of plastic is ground, filed and sanded from the front surface of the eye. We then make a painting shell by placing a clear polyethylene sheet between the artificial eye and a new layer of clear plastic, which then must be cured. This is the painting lens which affords us a way of judging the color of the prosthesis with all optical effects present, while the patient wears the prosthesis. When placed over the surface of the eye, the painting lens will bring the form back to the shape of the original wax model.
The coloring of the prosthetic eye is done with the greatest of care to match the companion eye in current appearance of the living tissue (photo 4). The patient must be present for this part of the procedure.
At intervals, the painted prosthesis can be placed in the socket (photo 5).
We can then judge the color with all illusions present and then alter colors as desired until completely satisfied (photo 6).
When the color is judged to be correct, the eye is returned to the final mold and the layer of transparent acrylic is cured onto the front surface to protect the color during polishing and wearing.
If the finished, highly polished prosthesis is not correct in every way, we will make changes until it is not possible to improve the eye any further. The procedure only takes 1 day to complete. This makes one-day service possible when scheduling early appointments. Difficult sockets may take 1 to 2 days longer. While this method is more time consuming than many other eye fitters, we feel that this is the way we can best produce a superior prosthesis. This same method is applied to fitting the corneal scleral shells.
We have a comfortable office and with the patient’s permission, any family member or friend of the patient is welcome to accompany him or her during parts of, or entire process. Just contact us and we will be happy to answer any questions you may have.
Printed with permission from Iowa Eye Prosthetics.