Purchase this article with an account.
Daniel V Palanker, Yannick Le Mer, Saddek Mohand-Said, Ralf Hornig, Guillaume Buc, Martin Deterre, Jose Alain Sahel; Photovoltaic Restoration of Sight in Atrophic Age-Related Macular Degeneration: one-year follow-up. Invest. Ophthalmol. Vis. Sci. 2020;61(7):4302.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To evaluate structural integration of the photovoltaic subretinal implant and its functional performance for restoration of central vision in patients with geographic atrophy.
A prospective study in 5 patients with visual acuity ≤20/400 due to geographic atrophy of at least 3 optic discs diameters and no foveal vision. The wireless photovoltaic chip (PRIMA, Pixium Vision) is 2x2mm in size, 30µm in thickness, containing 378 pixels of 100µm in width. Each pixel in the implant converts pulsed near-infrared light (880nm) projected from video glasses into electric current to stimulate the nearby neurons in the inner nuclear layer of the retina. Anatomy of the chip integration with the retina was assessed with OCT, fundus photography and FA. Prosthetic vision was assessed using Landolt C test and letter recognition.
In all 5 patients, chip implanted under the macula remains stable and functional, with a follow-up exceeding now 12 months in all patients. No decrease in natural eccentric visual acuity was observed in any of the patients. In all 4 patients with the chip placed subretinally, distance to the inner nuclear layer remains in the range of 35-39µm. All 5 patients perceive white-yellow patterns with adjustable brightness, in retinotopically correct locations within previous scotomata. All 4 patients with subretinal placement of the chip achieved letter acuity. Out of them, all 3 patients with central placement of the implant demonstrated acuity in the range of 20/460 - 20/550, which is just 10-30% below the sampling limit of resolution for this pixel size (20/420). Patient with the chip placed off-center demonstrated prosthetic acuity of 20/800. In the second phase of the trial, patients started using transparent augmented-reality glasses, and demonstrated simultaneous perception of the peripheral natural and the central prosthetic vision. Adjustable zoom on new video glasses significantly increased the equivalent prosthetic acuity.
Wireless chip PRIMA implanted under the atrophic macula in patients with geographic atrophy remains stable and functional during the 12 months of follow-up. It did not reduce the natural residual visual acuity in any of the patients. The implant provides central visual perception with acuity close to the single pixel size of the photovoltaic array. Video glasses with optical or electronic zoom provide significantly higher resolution.
This is a 2020 ARVO Annual Meeting abstract.
This PDF is available to Subscribers Only