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Enrollment completed for PMA arm of first US clinical trial of artificial iris
The implant aims to reduce photophobia and glare in patients with damaged irises or aniridia.
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An artificial iris is available to an increasing number of patients participating in a clinical trial because of a humanitarian use designation granted by the FDA.
The CustomFlex artificial iris prosthesis, manufactured by HumanOptics, is designed for patients with iris defects, iris damage and aniridia. The clinical trial’s sponsor, Clinical Research Consultants, plans to submit a premarket approval (PMA) application to the FDA when the trial is completed.
“The clinical trial is now in its second year. There currently are no artificial irises available in the United States, so this is going to be the first. Currently, it’s available only within the clinical trial confines,” Michael E. Snyder, MD, a medical monitor for the study, told Ocular Surgery News.
R. Doyle Stulting, MD, PhD, an OSN Cornea/External Disease Board Member, is also serving as a medical monitor for the study.
The implant is custom made for each patient. An artist uses a photo of a patient’s normal iris to match the implant to the photo, Snyder said.
“Typically, it looks pretty darn good, too, in most instances. The color matches are not always perfect, but they’re usually pretty good and they’re almost invariably better than nothing,” he said.
Function, appearance
“The device is initially made for and designed for trauma, but there are all kinds of different disorders of the eye that can be inflammatory or can follow surgical interventions that didn’t go as they should, or removal of tumors,” Snyder said. “The artificial iris gives an opportunity for us to allow these people to function more normally from a light sensitivity and glare perspective.”
The natural crystalline lens is about 10.5 mm in diameter, Snyder said.
“That fills pretty much the whole space from side to side of the eye. When the pupil is fully dilated, the natural lens still focuses all of the light that comes in,” he said.
However, because the typical IOL is only about 6 mm in diameter, pseudophakic patients with damaged irises or aniridia can experience adverse optical effects.
“If you’ve got somebody with a damaged iris, the light that’s getting focused is only the light that’s going through the implant, and all of the light that’s going around the implant is defocused. That can cause a couple kinds of problems,” Snyder said. “One, it can cause a second shadow image. You can have one clear image from light that is being focused through the implant, and you can have one shadow image from the light going around the implant. Further, the edge of the implant lens is exposed to light, so that can cause glare from the light that hits the edge and becomes dispersed.”
The implant can also improve the confidence of some patients with damaged or deformed irises, Snyder said.
“Some people might have an abnormal-looking iris, and they couldn’t care less. But for some people it’s a big deal, and it truly impedes how they’re able to interact with their peers and whether they’re going to go out into society looking down at the floor or looking at people in the eye and having confidence. It makes a big difference,” he said.
Clinical trial
The clinical trial comprises three arms. A PMA arm includes 180 subjects who met the primary inclusion criteria: age older than 22 years, a diagnosis of congenital or acquired full or partial iris defect in the study eye, and symptoms of light sensitivity, photophobia and/or glare. Subjects must be pseudophakic or aphakic or require cataract extraction. Enrollment for the PMA arm is completed, Snyder said.
A compassionate use arm has 150 slots, 42 of which have been filled.
“There are some patients who do not fit the normal study criteria, by way of example, children. Children are not permitted to be in the PMA arm of the study,” Snyder said. “There are some people who just don’t fit the criteria based on how the FDA asks the study to be structured, or they’ve got very unique problems with their eyes that preclude entry into the PMA arm, in which case they can potentially be entered into this compassionate use arm of the study.”
A continued access arm has 130 slots, eight of which have been filled. The FDA granted continued access because the iris implant is a humanitarian device and there are no available alternatives. The arm is for patients who did not make it into the PMA cohort but meet the inclusion criteria.
“Right now, [patients’] only other alternative would be to leave the borders of the United States for treatment or to have a substandard treatment that would leave them with residual optical problems,” Snyder said. – by Matt Hasson
- For more information:
- Michael E. Snyder, MD, can be reached at Cincinnati Eye Institute, 1945 CEI Drive, Cincinnati, OH 45242; email: msnyder@cincinnatieye.com.
Disclosure: Snyder reports he is a consultant for HumanOptics.