Low Vision Research

Retinitis pigmentosa is a neurodegenerative eye disease resulting in a loss of photoreceptors that can lead to complete blindness. Optogenetics involves generating artificial photoreceptors i.e. using gene therapy to cause neuronal cells to respond to light stimulation (GS030, GenSight Biologics). This technology combines the use of gene therapy and a medical device to restore retinal light sensitivity by modifying and training retinal ganglion cells to act as photoreceptor. The purpose of this study is to safely restore partial vision in advanced stages of retinitis pigmentosa. In this study, participants are injected with an adeno-associated viral vector and wear specialized light-stimulating goggles. Participants receive low-vision occupational therapy services also to promote improvements in functional vision. ​

Sahel, J. A., Boulanger-Scemama, E., Pagot, C., Arleo, A., Galluppi, F., Martel, J. N., ... & Roska, B. (2021). Partial recovery of visual function in a blind patient after optogenetic therapy. Nature Medicine, 27(7), 1223-1229.​​

Individuals who suffer from atrophic age –related macular degeneration (AMD) lose sight due to central retinal degeneration/loss of photoreceptors. This can lead to significant loss of central visual field. The Pixium Vision prima system, developed by Daniel Palanker, Stanford and Pixium Vision, is a sub-retinal miniature photvoltaic wireless implant. In this system, the pixels convert images that are projected from the video glasses using near-infrared light into electric current to stimulate inner retinal neurons. The implant is designed to restore central vision without compromising the residual peripheral field. The purpose of this study is to safely enable central vision stimulation in end-stage atrophic age-related macular degeneration. In this study, participants have the system implanted and then the occupational therapy low vision rehabilitation team provides rehabilitation to promote the person’s functional vision. ​​

Palanker, D., Le Mer, Y., Mohand-Said, S., Muqit, M., & Sahel, J. A. (2020). Photovoltaic restoration of central vision in atrophic age-related macular degeneration. Ophthalmology, 127(8), 1097-1104.​

Palanker, D., Le Mer, Y., Mohand-Said, S., & Sahel, J. A. (2022). Simultaneous perception of prosthetic and natural vision in AMD patients. Nature Communications, 13(1), 1-6.​

The Impact of Iris Vision on Function study is a pilot descriptive study led by Dr. William Smith, PI, and Dr. Jose Sahel, along with the support of Holly Stants, MS, OTR/L, SCLV, CLVT, Maria Shoemaker, OTR/L, clinical interventionist. The Iris Vision device is an electronic head-borne magnification device that is often used with persons who suffer from low vision. This study is evaluating those individuals with central visual acuity loss (e.g., age-related macular degeneration (AMD)) between the ages of 18 and 80 years old. Eligible participants are those who have no previous experience with the IrisVision system or any other head-mounted low vision optical devices, and who have best-corrected visual acuity (BCVA) in the severe and profound ranges:

• SEVERE visual impairment with BCVA ranging from 20/200-20/400 (n=8)
• PROFOUND visual impairment with BCVA worse than 20/400 (n=8)

The first goal of this study is to describe the effect of IrisVision on functional performance in various domains. The second goal is to describe how patients use the IrisVision in everyday life and how they perceive the system affects their lives.