A Second-Generation (44-Channel) Suprachoroidal Retinal Prosthesis: Interim Clinical Trial Results

• Published in: Translational vision science & technology Vol. 10; no. 10; p. 12
• Main Authors: Petoe, Matthew A., Titchener, Samuel A., Kolic, Maria, Kentler, William G., Abbott, Carla J., Nayagam, David A. X., Baglin, Elizabeth K., Kvansakul, Jessica, Barnes, Nick, Walker, Janine G., Epp, Stephanie B., Young, Kiera A., Ayton, Lauren N., Luu, Chi D., Allen, Penelope J.
• Format: Journal Article
• Language: English
• Published: United States The Association for Research in Vision and Ophthalmology 28.09.2021
• Subjects: Activities of Daily Living; Humans; Quality of Life; Retinitis Pigmentosa; Special Issue; Vision, Ocular; Visual Prosthesis
• ISSN: 2164-2591; 2164-2591
• DOI: 10.1167/tvst.10.10.12

To report the initial safety and efficacy results of a second-generation (44-channel) suprachoroidal retinal prosthesis at 56 weeks after device activation. Four subjects, with advanced retinitis pigmentosa and bare-light perception only, enrolled in a phase II trial (NCT03406416). A 44-channel electrode array was implanted in a suprachoroidal pocket. Device stability, efficacy, and adverse events were investigated at 12-week intervals. All four subjects were implanted successfully and there were no device-related serious adverse events. Color fundus photography indicated a mild postoperative subretinal hemorrhage in two recipients, which cleared spontaneously within 2 weeks. Optical coherence tomography confirmed device stability and position under the macula. Screen-based localization accuracy was significantly better for all subjects with device on versus device off. Two subjects were significantly better with the device on in a motion discrimination task at 7, 15, and 30°/s and in a spatial discrimination task at 0.033 cycles per degree. All subjects were more accurate with the device on than device off at walking toward a target on a modified door task, localizing and touching tabletop objects, and detecting obstacles in an obstacle avoidance task. A positive effect of the implant on subjects' daily lives was confirmed by an orientation and mobility assessor and subject self-report. These interim study data demonstrate that the suprachoroidal prosthesis is safe and provides significant improvements in functional vision, activities of daily living, and observer-rated quality of life. A suprachoroidal prosthesis can provide clinically useful artificial vision while maintaining a safe surgical profile.