Optimization of a Ganglion Cell-Based Optogenetic Therapy for Vision Restoration – Study by the EKFZ

Degenerative retinal diseases such as retinitis pigmentosa (RP) and geographic atrophy (GA) affect approximately 10 million people worldwide and lead to significant and often irreversible vision loss. Optogenetic therapies have emerged as a promising way to treat these diseases by using light-sensitive proteins (opsins) to impart light sensitivity to surviving retinal cells such as retinal ganglion cells (RGCs). In these therapies, visual inputs are converted into stimulation patterns via special camera-equipped glasses. Despite the potential for significant improvements in vision restoration, optogenetic approaches face significant challenges, such as achieving sufficient resolution and light sensitivity.

In response to these challenges, the EKFZ Center for Optogenetic Therapies is pioneering the development of advanced optogenetic strategies that focus on novel opsins such as ChReef, which are characterized by high efficacy at lower light levels, thereby expanding the dynamic range of visual perception while reducing the risk of phototoxicity. This initiative is part of a broader project to develop a gene therapy product (GTMP) and associated specialized stimulation devices for human patients.

Staging System for RGC Degeneration

With the kind support of Pro Retina – Foundation for the Prevention of Blindness, between 120 and 125 patients for the EKFZ study were recruited from the Eye Clinic of the University Medical Center Göttingen and through Pro Retina self-help groups. All have already attended their appointments. The aim of the study is to establish a staging system for RGC degeneration to identify suitable patients for optogenetic therapy. The prospective observational study began in March 2025 and is planned for five years (Clinical-Trials.gov ID: NCT07056738).