Photovoltaic Restoration of Central Vision in Atrophic Age-Related Macular Degeneration.

Abstract

PURPOSE:

Loss of photoreceptors in atrophic age-related macular degeneration results in severe visual impairment, although some peripheral vision is retained. To restore central vision without compromising the residual peripheral field, we developed a wireless photovoltaic retinal implant (PRIMA; Pixium Vision, Paris, France) in which pixels convert images projected from video glasses using near-infrared light into electric current to stimulate the nearby inner retinal neurons.

DESIGN:

We carried out a first-in-human clinical trial to test the safety and efficacy of the prosthesis in patients with geographic atrophy (ClinicalTrials.gov identifier, NCT03333954).

PARTICIPANTS:

Five patients with geographic atrophy zone of at least 3 optic disc diameters, no foveal light perception, and best-corrected visual acuity of 20/400 to 20/1000 in the worse-seeing study eye.

METHODS:

The 2-mm wide, 30-μm thick chip, containing 378 pixels (each 100 μm in diameter), was implanted subretinally in the area of atrophy (absolute scotoma).

MAIN OUTCOME MEASURES:

Anatomic outcomes were assessed with fundus photography and OCT for up to 12 months of follow-up. Prosthetic vision was assessed by mapping light perception, bar orientation, letter recognition, and Landolt C acuity.

RESULTS:

In all patients, the prosthesis was implanted successfully under the macula, although in 2 patients, it was implanted in unintended locations: within the choroid and off center by 2 mm. All 5 patients could perceive white-yellow prosthetic visual patterns with adjustable brightness in the previous scotomata. The 3 with optimal placement of the implant demonstrated prosthetic acuity of 20/460 to 20/550, and the patient with the off-center implant demonstrated 20/800 acuity. Residual natural acuity did not decrease after implantation in any patient.

CONCLUSIONS:

Implantation of the PRIMA did not decrease the residual natural acuity, and it restored visual sensitivity in the former scotoma in each of the 5 patients. In 3 patients with the proper placement of the chip, prosthetic visual acuity was only 10% to 30% less than the level expected from the pixel pitch (20/420). Therefore, the use of optical or electronic magnification in the glasses as well as smaller pixels in future implants may improve visual acuity even further.

• Authors: Daniel Palanker, Yannick Le Mer, Saddek Mohand-Said, Mahiul Muqit, Jose A Sahel
• Journal: Ophthalmology (Ophthalmology) Vol. 127 Issue 8 Pg. 1097-1104 (08 2020) ISSN: 1549-4713 [Electronic] United States
• PMID: 32249038 (Publication Type: Clinical Trial, Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)
• Copyright: Copyright © 2020 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Topics

• Electrodes, Implanted
• Feasibility Studies
• Female
• Humans
• Macula Lutea (pathology)
• Macular Degeneration (diagnosis, physiopathology)
• Male
• Middle Aged
• Recovery of Function (physiology)
• Tomography, Optical Coherence
• Visual Perception (physiology)
• Visual Prosthesis