Axorus (France)
French start-up developing a photoacoustic retinal prosthesis for AMD and other retinal degenerative diseases, based on technology licensed from Boston University (Chen Yang and Ji-Xin Cheng labs).
Key facts
- HQ: Paris, France.
- Founders / key stakeholders: Hélène Moulet (CEO / corresponding author on Leong 2026) and Jean-Damien Losasco (J-DL) — major stakeholders. Chen Yang and Ji-Xin Cheng (BU) — minor stakeholders. Yueming Li (BU) received partial Axorus research funding.
- Technology: PDMS/candle-soot/PDMS flexible photoacoustic film. 1030-nm pulsed NIR laser converts each pixel of light into a localised ultrasound wave (~51 µm lateral resolution) that stimulates mechanosensitive retinal cells surviving in AMD/RP. Unlike retinal-prosthesis electrical prostheses, the mechanism is acoustic not electrical; unlike photovoltaic (PRIMA), stimulation is ultrasound not charge injection. See retinal-prosthesis for full modality comparison.
- Product roadmap: developing a contact lens form factor that would project patterned NIR laser onto a subretinal PA film implant — no bulky external glasses required long-term (unlike PRIMA’s current headset). As of 2026 the technology is pre-clinical (rat subretinal implant results only).
- Funding: NIH (via BU PIs) and Axorus SAS directly.
- Stage (Aug 2026): Pre-clinical. Nature Communications paper published (Leong et al. 2026); next step is first-in-human safety study → clinical trial for blind patients. Chen Yang (BU) also plans a US start-up for domestic commercialisation.
Why it matters
The photoacoustic modality addresses a fundamental limitation of both electrical electrostimulation and photovoltaic prostheses:
- Resolution: 51-µm acoustic pixel from a 50-µm fibre — better than PRIMA’s current 100-µm pixel and potentially scalable to sub-20 µm for meaningful acuity.
- Coverage: the spatially continuous flexible film can in principle tile the full 25 mm² macula at up to 2,500 px/mm², whereas rigid photovoltaic chips are currently limited to 2×2 mm (7° visual field).
- Mechanism: stimulates mechanosensitive cells (via Piezo channels and upstream glutamate pathways), which persist even after photoreceptor and bipolar-cell loss.
- Safety: temperature rise <0.52 °C, MI <0.03–0.1, ISPTA <0.06–0.9 mW/cm² — all within FDA ophthalmic ultrasound guidelines.
Caveats / open questions
- Results so far are rat-only (ex vivo and in vivo); best achieved acuity not yet measurable (SC activation is not the same as letter acuity).
- Long-term biocompatibility not yet characterised (max 120 dpi for PDMS-CNT, 90 dpi for PDMS/CS/PDMS).
- Mechanosensitivity structures not fully characterised; long-term adaptation unknown.
- Surgery artefact (implant insertion track) needs refinement.
- Acoustic waves are bidirectional — RPE/choroid effects require further investigation.
- Patent portfolio for contact-lens form factor not publicly disclosed.
- COI: study partially funded by and co-authored by Axorus stakeholders.
Related pages
- retinal-prosthesis — modality context (photoacoustic vs photovoltaic vs electrical)
- retinal-prosthesis-companies — company schema
- visual-prosthesis — broader umbrella
- pixium-vision — comparable early-stage retinal prosthesis company (photovoltaic PRIMA)
- science-corp — current CE-marked commercial leader (PRIMA)
- brain-computer-interface — category hub
References
- Leong A, Li Y, Ruikes TR, et al. A flexible photoacoustic retinal prosthesis. Nat Commun 17, 815 (2026). https://doi.org/10.1038/s41467-025-67518-6 1
- Thurston A. “Could a Retinal Prosthesis Restore Sight for People with Age-Related Macular Degeneration?” The Brink, Boston University. 14 April 2026. https://www.bu.edu/articles/2026/retinal-prosthesis-age-related-macular-degeneration/ 2