Sources for this information include American Academy of Ophthalmology (AAO) [1]; VisionCare Ophthalmic Technologies, Inc. [2]; Centrasight [3]; GizMag [4]
(July 6, 2010) After a rigorous five-year testing period, the U.S. Food and Drug Administration (FDA) has given approval to the Implantable Miniature Telescope (IMT). The IMT has been developed by VisionCare Ophthalmic Technologies, Inc. [5] as part of Centrasight [3], a new patient care system which treats end-stage age-related macular degeneration (AMD). The telescopic implant is designed to improve visual acuity by reducing the impact of the central "blind spot" caused by AMD.
You can learn more about age-related macular degeneration (AMD) at An Introduction to Macular Degeneration [6] by Lylas G. Mogk, MD, a renowned expert on AMD and the founding director of the Visual Rehabilitation and Research Center of Michigan, part of the Henry Ford Health System Eye Care Services.
Dr. Isaac Lipshitz of VisionCare Ophthalmic Technologies, Inc. developed the new, implantable telescope to combat the effects of AMD. The device consists of an actual telescope the size of a pea.
During surgery, the natural lens of the eye is removed and the telescope is inserted into the capsule in the eye where the lens had been located. Light entering the eye is enlarged three times as it passes through the telescope and into the eye.
The result is improved vision because the image is larger when it reaches the cells in the retina and macula. The actual damage in the macula cannot be repaired using this procedure. The goal is to help the eye use the healthy parts of the retina to compensate for the damaged cells.
The larger size of the image means the damaged cells in the macula are responsible for converting a smaller portion of the total image. For example, patients looking at a family member may have a black hole where the entire face should be prior to surgery. With the telescope implanted, only the nose or mouth may be missing, which will allow the patient to recognize family members and see expressions on their faces.
To qualify for this procedure, potential patients must meet strict guidelines:
First, potential patients will receive testing with an external telescope that simulates the effect of an IMT to learn whether vision improvement is possible and whether peripheral vision in the eye that would not have the IMT is adequate for the patient's needs. Several visits with a low vision specialist are required for this preliminary testing.
Because the telescope replaces the natural lens of the eye, peripheral vision is lost in the eye receiving the telescope. For this reason, the telescope can be implanted in only one eye. The other eye is needed to provide peripheral vision to help with walking and other safety issues. With training, the brain can learn to choose which eye to use to look at something up close or off to the side.
As with any surgery, there are risks involved in the procedure, including possible damage to the cornea. The cornea is the clear membrane that covers the front of the eye.
In addition, VisionCare will conduct a post-approval study to monitor patient outcomes. A second smaller study will follow clinical trial patients for an additional two years.
Results from the two U.S. clinical trials have been published in peer-reviewed scientific journals including Ophthalmology, American Journal of Ophthalmology, and Archives of Ophthalmology.
Links:
[1] http://www.visionaware.org/american_academy_of_ophthalmology
[2] http://www.visioncareinc.net/press_releases/pr_1277848108
[3] http://www.centrasight.com
[4] http://www.gizmag.com/eye-telescope-gets-fda-approval/15681
[5] http://www.visioncareinc.net
[6] http://www.visionaware.org/what_is_age_related_macular_degeneration_amd
[7] http://www.visionaware.org/vision_rehabilitation_services