Patients with retinal degeneration lose sight due to the gradual demise of photoreceptors. Electrical stimulation of surviving retinal neurons provides an alternative route for the delivery of visual information. We demonstrate that subretinal implants with 70-μm-wide photovoltaic pixels provide highly localized stimulation of retinal neurons in rats. The electrical receptive fields recorded in retinal ganglion cells were similar in size to the natural visual receptive fields. Similarly to normal vision, the retinal response to prosthetic stimulation exhibited flicker fusion at high frequencies, adaptation to static images and nonlinear spatial summation. In rats with retinal degeneration, these photovoltaic arrays elicited retinal responses with a spatial resolution of 64 ± 11 μm, corresponding to half of the normal visual acuity in healthy rats. The ease of implantation of these wireless and modular arrays, combined with their high resolution, opens the door to the functional restoration of sight in patients blinded by retinal degeneration.
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http://dx.doi.org/10.1038/nm.3851 | DOI Listing |
To assess the repeatability of a microperimetry methodology for quantifying visual function changes in the junctional zone of eyes with geographic atrophy (GA) in the clinical trial context. A post hoc analysis of the OAKS phase III trial was conducted, which enrolled patients with GA secondary to age-related macular degeneration. Microperimetry using a standard 10-2 fovea centered grid was performed at baseline and follow-up visits.
View Article and Find Full Text PDFEur J Ophthalmol
January 2025
School of Medicine, Vita-Salute San Raffaele University, Milan, Italy.
Intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) medications are the primary treatment for neovascular age-related macular degeneration (nAMD). However, frequent administrations pose significant burdens on patients, healthcare providers, and systems. The treat-and-extend (T&E) regimen, which adjusts treatment intervals based on patient response, aims to reduce injection frequency while maintaining disease control.
View Article and Find Full Text PDFOphthalmic Genet
January 2025
Department of Ophthalmology, Casey Eye Institute, Oregon Health & Science University, Portland, Oregon, USA.
Introduction: Phosphoribosyl pyrophosphate synthetase 1 () is an X-linked gene critical for nucleotide metabolism. Pathogenic variants cause three overlapping phenotypes: Arts syndrome (severe neurological disease), Charcot-Marie-Tooth type 5 [CMTX5] (peripheral neuropathy), and non-syndromic sensorineural hearing loss (SNHL). Each may be associated with retinal dystrophy.
View Article and Find Full Text PDFArch Virol
January 2025
Departamento de Biología, Bioquímica y Farmacia, Universidad Nacional del Sur-Bahía Blanca, Buenos Aires, Argentina.
Neurodegenerative pathologies such as age-related macular degeneration currently have no cure or effective treatment. In this type of disease, the presence of amyloid-β peptides, oxidative stress, and inflammation trigger dysregulation of retinal pigment epithelial cells and progression toward the death of these cells, resulting in a loss of vision. The production of amyloid-β peptides, oxidative stress, and inflammation can be triggered in response to viral infections.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Ophthalmology, Kim's Eye Hospital, #156 Youngdeungpo-dong 4ga, Youngdeungpo-gu, 150-034, Seoul, South Korea.
To evaluate the outcomes and predictive factors for fluid resolution following three loading injections of faricimab for neovascular age-related macular degeneration(AMD). This retrospective study included patients diagnosed with treatment-naïve neovascular AMD who received three monthly injections of faricimab. Changes in best-corrected visual acuity(BCVA) and central retinal thickness(CRT) following treatment were evaluated.
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