Artificial retina lets patient see patterns by wireless stimulation of retina

20 April 2006

Bonn, Germany. A limited clinical study by Intelligent Medical Implants AG (IMI) has demonstrated that its patented, first-generation Learning Retinal Implant enabled patients to see light and simple patterns via a wireless transmission of data and energy.

The company claims that this is the first time in the history of the development of artificial vision that completely wireless transmission of data and energy into an implant in the eye of long-time blind persons has resulted in pattern recognition.

The Learning Retinal Implant has been successfully implanted in four patients for a duration of up to 13 weeks to date (the first implantation occurred in late-November 2005). Subsequent clinical testing of the IMI device with these patients began in January 2006 at the University of Hamburg (Germany) Medical School under principal investigator Prof. Gisbert Richard, Professor of Ophthalmology. Each of the implantations has been "extremely well-tolerated" and fixation of the implant has been "stable, with no inflammatory reactions," according to Prof. Richard.

"Each of these blind persons had no visual perception at all, yet upon wireless stimulation of the retina via the Learning Retinal Implant, they were able to 'see' something," said Hans-Juergen Tiedtke, CEO of IIP-Technologies, a subsidiary of IMI.

"One patient, for example, a 65-year-old female from Marienberg, Germany, has not had sight for more than a half century. From early childhood she has suffered from RP, meaning that she has not seen normally for more than 60 years. Nevertheless, in her first pattern recognition test, she described continuous objects such as a half circle. There is no doubt that this result is extremely positive, given that she has had no sight for almost her entire life, yet was still able to immediately receive a visual perception from electrical stimulation.

"While further clinical testing is needed and planned, we are truly delighted by these early results. It is our expectation that, in the not-too-distant future, our Learning Retinal Implant System, along with rehabilitation, may allow patients to recognize objects by identifying their size, as well as their position, movements and shapes. In other words, a blind person, using our Learning Retinal Implant System, is expected to be able to move independently in an unfamiliar environment — thus enabling him or her to lead an autonomous life. Indeed, development of a wireless visual prosthesis that could be implanted permanently with good results is the 'Holy Grail' of artificial vision," added Mr. Tiedtke.

IMI's initial clinical-indication focus is blind persons with Retinitis Pigmentosa ('RP'), one of the two most common causes of vision loss in persons over the age of 50 by hereditary degenerative retinal diseases. RP is considered irreversible, and no treatment or cure is known to date. Several million people are affected worldwide.

About Retinitis Pigmentosa

More than one million persons worldwide are affected by the hereditary disease, Retinitis Pigmentosa (RP), in which the light-sensitive cells of the retina slowly degenerate and die. In about one-third of the affected persons, the disease leads to total blindness over a period of years. Scientific studies have shown, however, that certain adjoining nerve cells remain intact even in persons blinded by the disease.

Most persons with RP develop early symptoms between the ages of 10 and 30. The most common first symptom is difficulty in seeing in poor light, for example outdoors at dusk, or in a dimly lit room. A second symptom is reduction of the visual field, in which sight is lost from the sides, or from above and below. This is often referred to as tunnel vision. All RP conditions are progressive. There is currently no treatment to cure RP or arrest its progress.

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