Three blind people, who had a subretinal implant inserted under their retina, were able to see shapes and objects within days of the operation. The results of these surgeries were reported by German scientists in the journal Proceedings of the Royal Society B.
According to the presentation, one patient surprised researchers by recognizing and locating objects on a table. He also demonstrated the ability to walk unaided around a room, approach specific individuals upon request, read a clock, and successfully describe seven shades of gray.
The electronic visual prosthesis was designed and created by Retinal Implant AG, Germany and the Institute for Ophthalmic Research, University of Tuebingen, in Germany. It is described by its authors as an “unprecedented advance in electronic visual prostheses” that could change the lives of people with retinitis pigmentosa – a degenerative eye disease that affects about 200,000 people world wide.
Retinitis pigmentosa consists of a collection of inherited disorders that creates abnormalities in the rods and cones of the retina and leads to slowly worsening vision and eventual blindness. Individuals first experience night blindness, then their field of view constricts until eventually they lose central vision as well.
Founding Director of Retinal Implant AG, Dr. Eberhart Zrenner – who is also Chairman of the University of Tuebingen Eye Hospital – said “The results of this pilot study provide strong evidence that the visual functions of patients blinded by a hereditary retinal dystrophy can, in principle, be restored to a degree sufficient for use in daily life.”
In the surgical procedure, the subretinal implant is implanted under the retina to replace the retina’s light receptor cones and rods which were lost during the retinal degeneration.
“It uses the eyes’ natural image processing capabilities beyond the light detection stage to produce a visual perception in the patient that is stable and follows their eye movements,” explained the researchers.
Unlike epiretinal implant procedures, where a device is placed outside the retina, this subretinal implant does not require the recipient to wear an external camera and processor.
Since the subretinal implant has considerably more light receptors than any other similar device, it provided patients with unprecedented visual clarity.
Photo courtesy London Vision Clinic