Elizabeth K. Baglin

Objective. To evaluate the effectiveness of a novel depth-based vision processing (VP) method, local background enclosure (LBE), in comparison to the comprehensive VP method, Lanczos2 (L2), in suprachoroidal retinal prosthesis implant recipients during navigational tasks in laboratory and real-world settings. Approach. Four participants were acclimatized to both VP methods. Participants were asked to detect and navigate past five of eight possible obstacles in a white corridor across 20–30 trials. Randomized obstacles included black or white mannequins, black or white overhanging boxes, black or white bins and black or white stationary boxes. The same four participants underwent trials at three different real-word urban locations using both VP methods (randomized order). They were tasked with navigating a complex, dynamic pre-determined scene while detecting, verbally identifying, and avoiding obstacles in their path. Main results. The indoor obstacle course showed that the LBE method (63.6 ± 10.7%, mean ± SD) performed significantly better than L2 (48.5 ± 11.2%), for detection of obstacles (p < 0.001, Mack–Skillings). The real-world assessment showed that of the objects detected, 50.2% (138/275) were correctly identified using LBE and 41.7% (138/331) using L2, corresponding to a risk difference of 8 percentage points, p = 0.081). Significance. Real world outcomes can be improved using an enhanced VP algorithm, providing depth-based visual cues (#NCT05158049).

Background: To assess the safety and stability profile of the suprachoroidal retinal prosthesis (ScRP) in participants with retinitis pigmentosa (RP) for 2 years from implantation. Methods: Four participants, with advanced RP and bare‐light perception vision were enrolled in a prospective, single arm unmasked interventional clinical trial and unilaterally implanted with a 44‐channel ScRP (NCT03406416). Electrical stimulation commenced in the psychophysics laboratory prior to use in local environments. Outcome measures included serious adverse events, adverse events, implant stability and implant functionality to assess the safety and stability profile over 2.0–2.7 years. Results: Surgical procedures took 204–260 min and were uncomplicated. Postoperative recovery was uneventful. Imaging confirmed the device position under the macula and the absence of retinal trauma. There were no serious adverse events and the adverse events that occurred were mild. All electrodes were functional at surgery completion, and only 3% electrodes lost functionality by study end. There was minor array movement (translational and rotational) within the first 10–15 weeks only. The electrode to retina distance increased as expected with fibrous capsule development, but plateaued in three of four participants within 12 months. Retinal and choroidal thicknesses were consistent with the underlying retinal dystrophic disease. Conclusions: The ScRP can be safely implanted in the suprachoroidal space and has minimal long‐term impacts on the eye, with no SAEs and only slight array movement seen over 2.0–2.7 years. Hence, the findings indicate approach feasibility and further multicentre studies are warranted.