Mini Telescope Implant Approved
SARATOGA, Calif., July 9, 2010 — The US Food and Drug Administration (FDA) has announced approval of an implantable miniature telescope (IMT) made by VisionCare Ophthalmic Technologies Inc. to improve vision in some patients with end-stage age-related macular degeneration (AMD).
Surgically implanted in one eye, the device — dubbed the “Implantable Miniature Telescope” (by Dr. Isaac Lipshitz) by VisionCare Ophthalmic Technologies — is a pea-size telescope that replaces the natural lens and provides an image that has been magnified more than two times.
AMD, a condition that mainly affects older people, damages the center of the retina (macula), resulting in a loss of vision in the center of the visual field. About 8 million people in the US are afflicted with AMD, and nearly 2 million of these already have significant vision loss, according to the National Eye Institute. AMD can make it difficult or impossible to recognize faces or to perform daily tasks such as reading or watching television.
Shown here is a telephoto ocular prosthesis designed for patients with end-stage age-related macular degeneration. The central optical portion of the device is a microlens system that renders a magnified image on the retina.
The IMT is designed to improve visual acuity. Magnification provided by the implant reduces the effect of the blind spot caused by end-stage AMD, which causes severe to profound central vision loss in both eyes. End-stage AMD results from either wet AMD that has progressed to scarring of the macula despite drug treatments or to dry AMD that has progressed to geographic atrophy.
"This innovation has the potential to provide many people with an improved quality of life," said Jeffrey Shuren, director of the FDA’s Center for Devices and Radiological Health.
The prosthetic lens is available in two models: one that provides 2.2× magnification and one that provides 2.7× magnification. Both are designed to magnify and project images onto a healthy portion of the retina. The IMT is intended to be implanted in only one eye; the nonimplanted eye is used to maintain peripheral vision.
The IMT is used in patients ages 75 years and older with stable severe to profound vision impairment (when vision impairment has not changed over time) caused by blind spots (bilateral central scotoma) associated with end-stage AMD. These patients also have evidence of a visually significant cataract.
Patients agree to undergo training with an external telescope with a low-vision specialist prior to implantation to determine whether adequate improvement in vision with the external telescope can be obtained and to verify if the patient has adequate peripheral vision in the eye that would not be implanted. Patients also agree to participate in a postoperative visual training program.
The tiny telescope is implanted in the place of the eye’s lens to help improve vision in patients with end-stage age-related macular degeneration, the leading cause of blindness. (Photo: VisionCare Ophthalmic Technologies)
In a 219-patient, multicenter clinical study of the IMT, 90 percent of patients achieved at least a two-line gain in either their distance or best-corrected visual acuity, and 75 percent of patients improved their level of vision from severe or profound impairment to moderate impairment. Results from a pair of US clinical trials, which were conducted at 28 ophthalmic centers, have been published in Ophthalmology, American Journal of Ophthalmology and Archives of Ophthalmology.
According to the manufacturer, the first-of-its-kind implant is integral to a new patient care program, dubbed CentraSight, for treating patients with end-stage AMD.
“This is truly a breakthrough technology for AMD patients, as their treatment options have been limited until now,” said Kathryn A. Colby, an ophthalmic surgeon at Massachusetts Eye and Ear Infirmary and an assistant professor of ophthalmology at Harvard Medical School, both in Boston. “The clinical results from the pivotal FDA trial have proven we can place this tiny telescope prosthesis inside the eye to help patients see better and, for some, even to levels at which they can recognize people and facial expressions that they could not before.”
“Despite the past decade of advancements in macular degeneration therapies, retina specialists still did not have a treatment for the many wet and dry AMD patients who progressed to end-stage disease,” said Julia A. Haller, ophthalmologist-in-chief of the Wills Eye Institute, and professor and chairwoman of the department of ophthalmology at Jefferson Medical College, both in Philadelphia. “Starting today, we can provide these patients with new hope.”
Although tiny, the IMT is a large device compared with the eye; therefore, implantation can lead to extensive loss of corneal endothelial cells (ECD), the layer of cells essential for maintaining the clarity of the cornea, and to chronic endothelial cell loss. The chronic rate of endothelial cell loss is about 5 percent per year. Significant losses in ECD may lead to corneal edema, corneal decompensation and the need for corneal transplant. In the study, 10 eyes had unresolved corneal edema, with five resulting in corneal transplants. The calculated five-year risk for unresolved corneal edema, corneal decompensation and corneal transplant are 9.2, 6.8 and 4.1 percent, respectively.
To ensure that the risks of IMT implantation are sufficiently and consistently communicated to patients, the FDA and VisionCare Ophthalmic Technologies created detailed labeling, including an Acceptance of Risk and Informed Decision Agreement that patients must complete prior to IMT implantation. The agreement provides a guide for patients and their physicians to discuss the risks associated with IMT implantation. Patients are to be given adequate time to review all of the information regarding the IMT.
As a condition of FDA approval, VisionCare Ophthalmic Technologies must conduct two postapproval studies. In one study, the company must continue follow-up on the subjects from its long-term follow-up cohort for an additional two years. Another study of 770 newly enrolled subjects will include an evaluation of the endothelial cell density and related adverse events for five years after implantation. The company announced that the first postapproval study will be led by Baltimore-based Oliver D. Schein, the Burton E. Grossman professor of ophthalmology at the Wilmer Eye Institute and professor of epidemiology at the Johns Hopkins University Bloomberg School of Public Health.
For more information, visit: www.centrasight.com.
- blind spot
- The spot on the retina where the optic nerve is attached; it is incapable of sensing light because of the absence of light receptors.
- A transparent optical component consisting of one or more pieces of optical glass with surfaces so curved (usually spherical) that they serve to converge or diverge the transmitted rays from an object, thus forming a real or virtual image of that object.
- The branch of medicine involved in the study of the anatomy, functions, diseases and treatments of the eye.
- 1. The photosensitive membrane on the inside of the human eye. 2. A scanning mechanism in optical character generation.
- An afocal optical device made up of lenses or mirrors, usually with a magnification greater than unity, that renders distant objects more distinct, by enlarging their images on the retina.
- visual field
- The angular field of view that is seen by the eyes when fixed on a point straight ahead. The normal binocular visual field is approximately 130° in diameter.
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