Photoelectric dye-based retinal prosthesis (OUReP) is an experimental subretinal implant developed at Okayama University that seeks to restore low-resolution vision in degenerative blinding disorders such as retinitis pigmentosa. Unlike electrode- or photodiode-based arrays, OUReP consists of a flexible polyethylene film (about 20 µm thick) whose surfaces are covalently coated with a photoelectric dye. When illuminated, the dye generates displacement currents (measurable as 100–200 mV surface-potential shifts under room-light levels) which in turn depolarise adjacent inner-retinal neurons. Because power generation and stimulation occur within the film itself, no external camera or battery is required.

Pre-clinical studies have shown that the film elicits light-evoked spikes in dystrophic rat and mouse retinas in vitro, improves behavioural and electrophysiological indices of vision after subretinal implantation in Royal College of Surgeons (RCS) rats, and restores visual-evoked-potential amplitudes for at least six months when implanted in a macaque model of macular degeneration. Surgical feasibility and ocular safety were further demonstrated in rabbits and dogs, aided by a single-use curved-tip “OUReP Injector” that rolls and inserts the film through a 1.4 mm cannula.

Extensive ISO 10993 biological evaluations found the device and its dye component non-toxic, and fabrication is performed under a dedicated clean-room quality-management system operated by Minori Industry in collaboration with the university.

A first-in-human, investigator-initiated trial has been designed for six ≥70-year-old patients with light-perception vision from retinitis pigmentosa, focusing on eyes that still retain inner-retinal layers on optical coherence tomography. OUReP is regulated in Japan as a class III medical device, with the injector classified as class II. The developers aim to offer a low-cost, wide-field prosthesis that aligns with global “no one left behind” sustainability goals.