Building a durable, flexible iris

In addition to giving the eye color, the iris offers protection. Composed of tissue, fibers and pigments, the iris acts as a curtain to restrict the amount of light reaching the retina.

For someone born without an iris or living with a damaged iris, glare can be debilitating.

“These are people who can’t drive in the daylight,” said Marshall Bowes Hamill, M.D., a professor of ophthalmology at Baylor College of Medicine’s Cullen Eye Institute. “So much light is coming in that they’re glare-disabled.” Congenital or traumatic aniridia— the absence of an iris—creates cosmetic concerns, as well.

But technology offers a solution. The CustomFlex Artificial Iris is a prosthetic made of thin silicone and produced by German company HumanOptics. Each prosthetic is individually sized and colored for each patient.

The device comes “in two flavors,” Hamill said. One is a silicone sheet—“very soft, very pliable”—and the other is a silicone sheet embedded with fiber mesh, strong enough to be sewn to an eyeball.

For a patient outfitted with the device in combination with cataract surgery, surgeons perform a standard cataract operation. They remove the lens of the eye and replace it with an artificial lens, leaving the original back surface of the eye’s natural lens—the “posterior capsule”—and fitting the new lens into this natural shrink wrap. The artificial iris goes into the same wrapper, so no stitches are required.

“But in a traumatic injury, if you’ve lost your lens and part of your iris, we don’t have any support structure, so now we have to support that iris implant by actually sewing it to the eyeball,” said Hamill, who participated in the clinical trials leading up to the U.S. Food and Drug Administration’s approval of the device in May 2018.

The CustomFlex Artificial Iris costs $7,700, according to the manufacturer, and is not yet covered by insurance. Hamill said he hopes insurance companies will sort out reimbursement soon.

“This, in my opinion, is a significant advance in both reconstruction function surgery and reconstruction aesthetic surgery,” he said. “It’s a game-changer.”