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Restoration: Nanotechnology in Tissue Replacement and Prosthetics
Published in Harry F. Tibbals, Medical Nanotechnology and Nanomedicine, 2017
Retinal degeneration or detachment is one of the main causes of vision loss. Therefore, most efforts to develop a visual neuroprosthesis have attempted to stimulate the ganglia cell layer behind the retina, as the simplest strategy to interface to the visual signal processing that is in place on the optical nerve path. Some prostheses have been designed and tested that stimulate the visual cortex directly, producing a low-resolution pattern of visual sensation, and some have mapped digitized imaging onto touch sensors in the back or other skin areas, in a kind of transposed Braille that delivers images rather than encoded letters.
Gene Therapy for Retina and Eye Diseases
Published in Yashwant V. Pathak, Gene Delivery Systems, 2022
Leber congenital amaurosis (LCA) is a rare ocular disorder. It develops due to the inheritance of autosomal recessive genetic conditions causing severe loss of vision in infants. Vision loss is the result of retinal degeneration causing dysfunction of photoreceptors that precipitate an inability to capture images. Electroretinography (ERG) measures electrical retinal activity in response to impingement by light. The ERG tracings show diminished activity. Additional symptoms include cataracts, strabismus, photophobia, keratoconus, and/or nystagmus (4–5).
The individual and combined effects of spaceflight radiation and microgravity on biologic systems and functional outcomes
Published in Journal of Environmental Science and Health, Part C, 2021
Jeffrey S. Willey, Richard A. Britten, Elizabeth Blaber, Candice G.T. Tahimic, Jeffrey Chancellor, Marie Mortreux, Larry D. Sanford, Angela J. Kubik, Michael D. Delp, Xiao Wen Mao
Ocular damage and retinal degeneration can be promoted by many factors including aging, ischemia, fluctuation in oxygen tension, oxidative stress, and increased intraocular pressure.120 Visual disturbances associated with space travel may be due to exposure from altered gravitation changes and ionizing radiation.116,120–122 Although some ocular changes experienced by astronauts have been measured and evaluated,117,118 validation was difficult due to the limited subject cohort size and test constraints on ISS. Furthermore, the underlying mechanisms of these ocular disturbance and factors contributing to the development of damage are currently unclear. Comprehensive ground-based rodent study models to simulate space condition including low-dose ionizing radiation and microgravity is warranted to determine the impact of the space environment on ocular structure and function.
Cytotoxicity and genotoxicity of light emitted by incandescent, halogen, and LED bulbs on ARPE-19 and BEAS-2B cell lines
Published in Journal of Toxicology and Environmental Health, Part A, 2018
Marta Gea, Tiziana Schilirò, Paola Iacomussi, Raffaella Degan, Sara Bonetta, Giorgio Gilli
Constant exposure to light in excess can produce retinal degeneration as a consequence of photoreceptor or retinal pigment epithelium (RPE) cells' death (Contin et al. 2016). Moreover, light in excess may damage the human vision promoting retinal degeneration or accelerating some genetic diseases, such as retinitis pigmentosa or age-related macular degeneration (Contin et al. 2016).
Journey of Visual Prosthesis with Progressive Development of Electrode Design Techniques and Experience with CMOS Image Sensors: A Review
Published in IETE Journal of Research, 2018
Later on multifocal electrical stimulation of the retina was found to be a viable approach for providing vision in patients suffering from RP or outer retinal degeneration. Intraocular prosthesis with the provision of anti-irreversible toxic actions at electrode-tissue interface was found to be perfect for the job [98].