Argus II Bionic Eye: Good News for Retinitis Pigmentosa Sufferers
In this context, one very alarming disease is retinitis pigmentosa (RP). A genetic disorder, it involves retinal pigment epithelium or the photoreceptor layer, causing their destruction and afflicting the vision. The loss of sight is progressive and may become evident from infancy or later age, affecting first side vision and night vision and then central vision later. However, scientists have devised methods to overcome this difficulty. A number of treatment options have been searched in this regard.
In 2006, stem cells from mice were transplanted to relieve blindness. In 2008, scientists at the Osaka Bioscience Institute discovered a protein named Pikachurin which could help treat blindness. Gene therapy underwent studies in 2010, along with ophthalmic solution UF-021 (Product Name Ocuseva (TM)) by R-Tech Ueno (Japanese Medicine manufacture enterprise) to aid against RP. Other than this, retinal implants, transplants and drug therapies are also under scientists’ radar to abate RP.
The first implantable device has now been approved by FDA – US Food and Drug Administration. It is Argus II Retinal Prosthesis System which will treat RP in adult patients. It consists of a small video camera, transmitter mounted on a pair of eyeglasses, video processing unit (VPU) and an implanted retinal prosthesis (artificial retina). The video collects the information while the transmitter sends it to the prosthetic. The prosthetic translates this information into electrical impulses that trigger the production of images by the retina.
The new treatment device is hoped to bring relief to the people suffering from RP. Jeffrey Shuren, M.D., director of the FDA’s Center for Devices and Radiological Health says in his interview, “This is a great opportunity for people who have lost their sight due to RP and have no other means of FDA approved treatment options for correcting. It is a surgically implanted device and helps the sufferers to be more mobile and perform daily activities.’’
The Argus II system has a few specifications for its usage. It is available for use in adult population, in people having age of 25 years or above, complaining of severe RP. These people have meager light perception (can perceive light, but not its direction) or no light perception in both eyes. There is also evidence of intact inner layer retina function, and a previous history of the ability of the sufferer to see forms.
The implantation requires follow-up and patients must be willing and able to receive the recommended post-implant clinical follow-up, device fitting, and visual restoration. Although Argus II Retinal Prosthesis System cannot restore vision to patients, it may allow them to detect light and dark in the environment, helping them to identify the location or movement of objects or people. The FDA approved the Argus II Retinal Prosthesis System as a humanitarian use device. In order to gain its authorization for use as humanitarian device, a company must prove with moderate guarantee that the device is safe and that its probable benefit are more than the adverse effects. The company also must demonstrate that there is no device equal in quality and efficacy available to treat or diagnose the disease or condition.
Before being approved, the device was analyzed by FDA in a clinical study of 30 participants with RP who received the Argus II Retinal Prosthesis System. The adverse effects following implantation surgery were investigated and patients were regularly assessed for their vision for at least two years following the implant. Results from the clinical study showed that there was an improvement in the ability of the participants to perform basic activities better with the Argus II Retinal Prosthesis System than without it. The activities for which the new device was tested included casual performances like detecting and touching a square on a white field; locating the direction of a action; recognizing large letters, words, or sentences; distinguishing street curbs; walking on a sidewalk without stepping off; and matching black, grey and white socks.
It was concluded that 19 of the 30 study patients experienced no adverse events related to the device or the surgery. Eleven study subjects experienced 23 serious adverse events, which constitute of deterioration of the conjunctiva (the clear covering of the eyeball), dehiscence (splitting open of a wound along the surgical suture), retinal detachment, inflammation, and hypotony (low intraocular pressure).
The project was supported and funded by three government organizations. The Department of Energy, National Eye Institute at the National Institutes of Health and the National Science Foundation collectively funded the project for the development of this new device for people suffering from RP. A massive contribution of more than $100 million was made on their behalf, and also the means for material design and other basic research for the project.
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