Abstract:

Retinal degenerative diseases lead to blindness due to loss of photoreceptors, while neurons in the inner retinal layers remain largely preserved. We developed a system substituting the lost photoreceptors with photovoltaic arrays. Visual information captured by a camera is projected onto the retina from augmented-reality glasses using pulsed near-infrared (880nm) light. Subretinal pixels convert light into electric current, stimulating the second-order retinal neurons. This approach preserves many features of natural vision, avoids the use of bulky electronics and wiring, and allows scaling the number of electrodes to thousands.

43 patients blinded by atrophic age-related macular degeneration across 17 centers in 5 European countries were implanted with 2x2mm wireless photovoltaic arrays composed of 100mm pixels (PRIMA, Pixium Vision). Clinical trials demonstrated monochromatic form vision with a letter acuity closely matching the pixel size of the implant (20/420). Remarkably, central prosthetic vision is perceived simultaneously with the peripheral natural vision. Using electronic zoom, patients could read much smaller fonts – up to the letter size corresponding to acuity of 20/63.

To reduce the pixel size further, while providing sufficiently deep stimulation of the inner retina, we developed various strategies for shaping the electric field, including current steering between pixels and 3-dimensional electrodes. Grating acuity with pixels down to 40mm in rats matched the pixel pitch, while with 20mm, it reached their natural resolution limit of 28mm. If successful in clinical trials, the next-generation implant with 20mm pixels may increase acuity up to 20/80 even without zoom.

Gastgeber: Prof. Günther Zeck, öffnet in einem neuen Fenster und Dr. Paul Werginz, öffnet in einem neuen Fenster

Datum: 24. März 2025, 13:00 Uhr

Raum: Seminarraum 387, öffnet eine externe URL in einem neuen Fenster