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Impact of Retinal Stimulation on Neuromodulation
Published in Yu Chen, Babak Kateb, Neurophotonics and Brain Mapping, 2017
The most familiar of the retina’s ten layers is the one with photoreceptors, split into the outer and inner segments of rods and cones. Photoreceptors need nourishment from another retinal layer, the retinal pigment epithelium (RPE). The constant interaction between the RPE and the rod photoreceptors is termed the visual cycle, triggered by lighting changes. Cones have a chemical interchange with Mueller cells. The external limiting membrane (or outer limiting membrane) separates the cell bodies of the photoreceptors from their outer and inner segments. The line of cell bodies is termed the outer nuclear layer of the retina. Oftentimes, a photoreceptor integrity line is evaluated on retinal imaging, but it is not a retinal layer. It simply represents the junction between the outer and inner segments of the photoreceptors, and its assessment is useful for determining the progress of various diseases.
Medical retina
Published in Mostafa Khalil, Omar Kouli, The Duke Elder Exam of Ophthalmology, 2019
The nine layers of the NSR, from inwards to outwards, are as follows: Internal limiting membrane: Separates the retina from the vitreous.Nerve fibre layer (NFL): Contains ganglion cell axons that come together to form the optic nerve. Presents in the macular area and travels nasally to the optic nerve directly through the papillomacular bundle.Ganglion cell layer: Contains the cell bodies of the ganglion cells. Involved in transmitting visual information to the brain including the stimulus required for light pupillary response.Inner plexiform layer: Synaptic layer between second and third order neurons.Inner nuclear layer: Contains cell bodies of bipolar cells and cell bodies of Müller cells (principal glial cells of the retina).Outer plexiform layer: Synaptic layer between photoreceptors and bipolar cells.Outer nuclear layer: Contains cell bodies of rods and cones.External limiting membrane (ELM): Connections between photoreceptors and Muller cells create the ELM.Photoreceptor layer: Composed of rods and cones.
Nerve Growth Factor Promotes Retinal Neurovascular Unit Repair: A Review
Published in Current Eye Research, 2022
Baohua Li, Bobiao Ning, Fan Yang, Chengwei Guo
There are five types of retinal neurons: photoreceptors, horizontal cells, bipolar cells, amacrine cells, and ganglion cells. Photoreceptors predominantly comprise cones and rods and are located in the outer nuclear layer (ONL). The cell bodies of horizontal, bipolar, and anaplastic cells are primarily located in the internal nuclear layer (INL), whereas retinal ganglion cells (RGCs) are distributed in the ganglion cell layer (GCL).14 The outer plexiform layer (OPL) and the inner plexiform layer (IPL) are the sites where these three levels of neurogenic synapses are connected.15 The internal limited membrane (ILM) brings together the synapses of ganglion cells, which are sent by the optic nerve to the visual cortex to complete the transmission of visual signals.
Multimodal Imaging in Dengue-Fever-Associated Maculopathy
Published in Ocular Immunology and Inflammation, 2018
Marib Akanda, Sapna Gangaputra, Shilpa Kodati, Alexander Melamud, H. Nida Sen
About 28–34% of patients with dengue maculopathy have yellow–orange lesions seen on funduscopic exam corresponding to the outer retinal changes seen on OCT.6 Characteristic lesions of AMN occurred in 55.6% of dengue maculopathy cases seen at one center,7 which are best visualized on near-infrared reflectance.8,11 OCT findings include hyperreflectivity of the outer nuclear layer and outer plexiform layer in the acute phase, followed by irreversible outer segment disruption and outer nuclear layer thinning that persist long term with scotomas even after visual recovery.9–11 Our patient did not show the yellow lesions, but demonstrated these OCT findings, with resolution of the outer nuclear and outer plexiform layer swelling after 4 weeks.
Effect of autologous growth factors on apoptosis and thickness of the outer nuclear layer in an experimental retinal degeneration model
Published in Growth Factors, 2020
Emin Ozmert, Sibel Demirel, Umut Arslan, Özlem Biçer, Ozan Ahlat, Figen Şermet
Sodium iodate (NaIO3) denatures peptides in RPE leading to intracellular accumulation of mutant proteins and disruption of ETC (Reisenhofer, Balmer, and Enzmann 2017; Wang et al. 2014; Lin et al. 2018). This is a good option for creating a pigmented outer retinal degeneration model and can measure the thickness of the outer nuclear layer (ONL) in rabbits. The outer nuclear layer of the retina contains the nuclei of the cone and rod photoreceptors. Loss of the cellular integrity in this layer causes irreparable loss of the photoreceptors and the capacity for visual functions as seen in the retinitis pigmentosa (RP).