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FDA advisory panel: Implantable telescope not recommended for approval
Device designed to restore sight to patients with AMD or Stargardt’s macular dystrophy was not recommended for approval by an FDA panel.
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The Implantable Miniature Telescope was found to be “not approvable” by an advisory panel to the Food and Drug Administration. The FDA’s Ophthalmic Devices Panel cited safety and efficacy concerns when recommending against approval of the device at its meeting in July.
The Implantable Miniature Telescope, or IMT, manufactured by California-based VisionCare Ophthalmic Technologies Inc., is designed for patients with moderate to severe bilateral central vision impairment due to either dry or scar-stage wet age-related macular degeneration or Stargardt’s macular dystrophy.
The Implantable Miniature Telescope is a micro-sized precision telescope that is implanted in one eye in an outpatient surgical procedure under local anesthesia. The implanted eye provides central vision, and the non-implanted eye is used for peripheral vision. The device provides magnification of 3X or 2.2X , depending on the model. A magnified image is projected over a wide field of the retina to improve the ability to recognize images that were either difficult or impossible to see without the implant, according to VisionCare.
![R. Doyle Stulting, MD, PhD [photo]](/images/osn/200608b/stulting.jpg) R. Doyle Stulting |
At the FDA hearing on July 14, R. Doyle Stulting, MD, PhD, OSN Corneal/External Disease section member, one of the investigators who had implanted the device in a 1-year multicenter clinical trial, said that 90% of the study population had severe or profound visual impairment at the study’s start, and patients had a positive response to the device in terms of quality of life.
“It is not a perfect device that cures macular degeneration or even stops its progress, but the data support its approval under limited circumstances,” Dr. Stulting said, according to a webcast of the meeting that was viewed on DVD.
According to an FDA document summarizing information presented at the meeting, 90.1% of implanted eyes experienced an improvement of two lines or more of either near or distance visual acuity. This exceeded the primary efficacy endpoint of the study, which was an improvement of two lines or more in either near or distance visual acuity in 50% of the implanted eyes at 1 year.
The primary safety endpoint of the study was a loss of less than 17% in mean endothelial cell density at 1 year after implantation of the IMT, according to the FDA document. In the study, the mean endothelial density decreased by 25.3% at 1 year.
Panel discussion
The FDA panel recommended by a 10-to-3 vote that the VisionCare Technology product be found “not approvable.” The FDA is not bound to follow the recommendations of its advisory panels, but in most cases it does.
The “not approvable” designation indicates that the panel found the study data did not provide “reasonable assurance that the device is safe and effective under the conditions of use prescribed, recommended, or suggested in the proposed labeling,” according to a summary of the panel meeting.
The panel’s decision was based on unresolved safety concerns, in addition to uncertainty regarding the efficacy of the device, according to the summary. The panel noted that the absence of morphometric analysis of endothelial cell density data did not allow panel members to adequately analyze the chronic rate of endothelial cell density loss, the major safety concern for the device.
Panel members agreed that while the device showed promise and is a much-needed technology for patients with dry or scar-stage wet age-related macular degeneration or Stargardt’s macular dystrophy, VisionCare Ophthalmic Technologies must present more data to demonstrate the safety of the product.
The panel also cited confounding factors that may influence the efficacy of the device, including the large incision necessary for implantation of the device and the risk that patients might need corneal transplants years after the implantation.
Panel member Neil M. Bressler, MD, made the motion not to approve the device. He said he made it specifically because of the 25% loss in endothelial cells, which was seen in the first 3 months after the device was implanted.
“Patients need something that does indeed work, but it has to stand on its own merits by the data presented here,” Dr. Bressler said at the panel meeting. “We have to make a decision scientifically to advise the FDA. In terms of safety, I believe that it has not been shown yet, by the information we have, to be safe. But I also believe, in terms of efficacy, that this is a very difficult task to sort out.”
He said it was difficult to know how much of the patients’ improvement in visual acuity came from removal of their cataracts, how much came from learning to use eccentric fixation over time and how much came from “the drive of the patient to try to improve.”
VisionCare Ophthalmic Technologies officials were unavailable to comment on the results of the panel meeting.
Clinical trials
The multicenter clinical study for FDA premarket approval included 217 patients with AMD at 28 sites. The mean age of the patients was 76 years and mean visual acuity in the study eyes preoperatively was 20/316. A year after the device was implanted, 90.1% of eyes patients showed improved distance and near visual acuity.
Ten patients reported a loss in acuity in either distance or near vision. Investigators removed eight of the devices, four of them from patients who were dissatisfied with how they worked.
Patients were monitored for safety and efficacy. One year after implantation, most patients gained three or more lines of distance or near visual acuity and improvement in their activities of daily living. The most common complication was transient inflammation, according to the company.
The panel noted that the trial should have included a control group.
For more information:
- R. Doyle Stulting, MD, PhD, can be reached at the Department of Ophthalmology, Emory University, Atlanta, GA 30319; 404-778-6166; fax: 404-778-6165.
- Neil M. Bressler, MD, is the James P. Gills Professor of Ophthalmology at the Wilmer Eye Institute of Johns Hopkins University. He can be reached at 550 North Broadway, Suite 115, Baltimore, MD 21205; e-mail: nmboffice@jhmi.edu.
- VisionCare Ophthalmic Technologies Inc., maker of the Implantable Miniature Telescope, can be reached at 14395 Saratoga Ave., Suite 150, Saratoga, CA 95070; 408-872-9393; fax: 408-872-9395; Web site: www.visioncareinc.net.
- Erin L. Boyle is an OSN Staff Writer who covers all aspects of ophthalmology.