What it takes to make an eye

It passes the grandkid test: Sherry McClain’s grandkids can’t tell the difference between her real and her prosthetic eye, and most other people wouldn’t notice either.

When Sherry—of Platteville, Wisconsin—had two spots on her left eye and inner eyelid identified as suspicious for evolving melanoma, she chose to come to University of Iowa Hospitals and Clinics. Mark Greiner, MD, confirmed the melanoma diagnosis, and the spot on her eye was removed. But the cancer grew back. After exhausting other options, Sherry made the decision to have her eye removed and replaced with a prosthetic eye. She had the procedure in the fall of 2016.

Pronk makes adjustments to Sherry’s prosthetic eye to ensure a proper fit.

The timing turned out to be good for Sherry, as the Department of Ophthalmology and Visual Sciences at UI Hospitals and Clinics had just launched the Ocular Prosthetics Service in the summer of 2016. The service is led by Lindsay Pronk, an ocularist who specializes in creating and fitting prosthetic eyes for people who have had an eye removed. Patients may need a prosthetic eye for a variety of reasons, including cancer, accidents, developmental issues (in children), glaucoma, or serious infections.

The shape of the prosthetic eye is not actually spherical, as one may expect. When a patient’s eyeball is surgically removed, a spherical implant is permanently attached to the inside of the eye socket. The back of the prosthetic eye is concave, and it is made to fit perfectly over the implant already in the eye socket.

Making of an eye: the process

First, Pronk makes an impression of the eye socket by injecting alginate into the space. The alginate is the same material used to make dental impressions. It is safe and takes less than a minute to set.

Pronk begins the process of adding “veins” (red thread) and painting a prosthetic eye.

Pronk begins the process of adding “veins” (red thread) and painting a prosthetic eye.

Next, Pronk makes a mold around the impression. Liquid wax is poured into the empty mold to make a wax replica of the eye. A plastic iris is attached to the replica and is placed in the eye socket to ensure correct direction of gaze and the proper fit, symmetry, and comfort of the prosthetic eye. The wax is adjusted as necessary, and when the fitting is complete, a second mold is made around the wax replica.

Adding a layer of clear plastic

Adding a layer of clear plastic

A white polymer mixture is placed into this mold, compressed, and cooked for 35 minutes to create the acrylic eye, which is then trimmed and polished. Pronk creates “veins” on the surface using red cotton thread covered by a layer of clear plastic, and the prosthetic eye is cooked again. Pronk then spends three to four hours painting the prosthesis using multiple layers and colors of paint to give the iris depth and to match the patient’s other eye. Throughout the process, Pronk makes tiny adjustments to ensure proper curvature, a natural-looking gaze, and precise symmetry to the other eye, both in shape and coloring.

The final product

The final product

When both Pronk and the patient are happy with the prosthesis, it is placed in a water bath for 90 minutes then given a final trim and polish.

Lastly, the patient learns how to insert and remove the prosthetic eye (although the patient rarely has to remove it), as well as proper care and handling.

“I’m very happy with it,” Sherry says, “One of my coworkers even said, ‘Wow it looks great, I never would’ve noticed.’”

Although Pronk is the only ocularist at UI Hospitals and Clinics, she works in collaboration with a variety of other providers and staff members, including oculoplastic surgeons, pediatric providers, and oncologists at Holden Comprehensive Cancer Center, as well as consulting with the patient’s local providers.

“Every day is a challenge,” Pronk says of her job. “Everyone’s eye is so different, it’s a brand new experience with each person.”

And as for Sherry, what does it feel like to have a prosthetic eye? “It kind of felt like a thumb in my eye at first, but I’ve gotten used it,” she says with a smile.

Patient Sherry McClain and Lindsay Pronk, ocularist

Patient Sherry McClain and Lindsay Pronk, ocularist

Write a Reply or Comment

Your email address will not be published.

When commenting, please be respectful of others.