An international research team led by Prof. Dr. Sedat Nizamoğlu from the Department of Electrical and Electronics Engineering at Koç University has developed a next-generation, safe, and wireless stimulation technology for retinal degenerative diseases that cause vision loss. The study was published in Science Advances, one of the world’s most prestigious scientific journals.
Retinal degenerative disorders affect millions of people worldwide and currently have no curative treatment. Existing retinal implants, however, face significant clinical limitations due to their bulky structures, complex electronic components, or the need for high-intensity visible light. To overcome these challenges, researchers at Koç University set out to develop an ultra-thin, biocompatible system capable of directly converting light into biological electrical signals.
To achieve this, the team designed a photovoltaic nano-assembly combining zinc oxide nanowire arrays with silver–bismuth–sulfide nanocrystals. This structure enables the conversion of near-infrared light, which penetrates tissue more deeply and safely than visible light, into precisely controlled electrical stimulation without causing damage to ocular tissue. Importantly, this process operates at low light intensities that remain well below established ocular safety limits and does so using a fully wireless, ultra-thin architecture.
The performance of the system was evaluated using retinal models from rats with vision loss. Experiments demonstrated strong, repeatable, and temporally precise responses in retinal neurons. In addition, comprehensive analyses of cell viability, biocompatibility, and long-term stability showed that the structure did not induce cellular stress or toxicity and is suitable for prolonged use. The negligible temperature increase observed during operation further highlights the safety advantages of the approach.
What distinguishes this technology from existing retinal implants is its ultra-thin active layer, its use of safer near-infrared light instead of visible light, and its completely wireless design that eliminates the need for external cables or electronic components. These features make the platform a strong candidate not only for visual prostheses but also for broader neuromodulation applications targeting electrically excitable tissues such as the brain, heart, and muscles.
Commenting on the study, Prof. Dr. Sedat Nizamoğlu said: “This study demonstrates that a nanotechnological retinal implant approach could potentially restore vision in the future for individuals who have lost visual function due to macular degeneration and retinitis pigmentosa. Inorganic nanocrystals, which received the 2023 Nobel Prize in Chemistry, are highly promising for retinal prosthesis technology when implemented using functionally optimized nanoarchitectures. Operating with near-infrared light, this nanoscale system offers a significant alternative to existing approaches in terms of performance. Our findings open new avenues not only for visual prosthetics but also for a wide range of biomedical applications that interact with the nervous system.”
This work, carried out at Koç University, once again underscores the university’s interdisciplinary research environment and its commitment to high-impact scientific innovation, while paving the way for the development of safer and more effective future treatments for individuals living with vision loss.