Retinal whole-mount preparations from the eyes of the North American paddlefish, Polyodon spathula, were examined with a combination of bright field and differential interference contrast microscopy. The entire retina was mapped and population counts of rod and cone photoreceptors were made at regular intervals throughout the retina. The retina is dominated by rods, but a significant percentage (ca. 38%) of the photoreceptors are cones. Mean cone packing density for the entire retina is 6,402+/-1,216 cones/mm2. There is a small (16%) but statistically significant difference between cone packing density in the dorsal retina (6,674+/-1,168 cones/mm2) and the ventral retina (5,745+/-1,076 cones/mm2). There is no region of unusually high cone concentration that might be construed as a fovea or a visual streak. Mean rod packing density for the entire retina is 10,271+/-1,205 rods/mm2. Except in the far periphery, where rods are less numerous, the density of rods is fairly uniform throughout the retina. The data are discussed with regard to paddlefish habitat and behavior.
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http://dx.doi.org/10.1002/jez.a.63 | DOI Listing |
Nat Commun
December 2024
Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
Currently there are no effective treatments for an array of neurodegenerative disorders to a large part because cell-based models fail to recapitulate disease. Here we develop a reproducible human iPSC-based model where laser axotomy causes retrograde axon degeneration leading to neuronal cell death. Time-lapse confocal imaging revealed that damage triggers an apoptotic wave of mitochondrial fission proceeding from the site of injury to the soma.
View Article and Find Full Text PDFJAMA Ophthalmol
December 2024
Casey Eye Institute, Oregon Health and Science University, Portland.
Importance: Capturing high-quality images of the entire peripheral retina while minimizing the use of scleral depression could increase the quality of examinations for retinopathy of prematurity (ROP) while reducing neonatal stress.
Objective: To evaluate whether an investigational handheld ultra-widefield optical coherence tomography (UWF-OCT) device without scleral depression can be used to document high-quality images of the peripheral retina for use in ROP examinations.
Design, Setting, And Participants: This was a prospective, cross-sectional study in the neonatal intensive care unit at a single academic medical center.
Cureus
November 2024
Institute of Ophthalmology, Jawaharlal Nehru Medical College and Hospital, Aligarh Muslim University (AMU), Aligarh, IND.
Background: Diabetes mellitus (DM) is a global disease that is strongly associated with both microvascular and macrovascular complications. A significant proportion of individuals with diabetes develop diabetic retinopathy (DR), a microvascular complication that can lead to blindness, particularly in working-age adults. Diabetes adversely affects the entire neurosensory retina, with accelerated neuronal apoptosis and activation or altered metabolism of neuroretinal supporting cells.
View Article and Find Full Text PDFTransl Vis Sci Technol
December 2024
Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, Baltimore, MD, USA.
Purpose: Visual evoked potentials (VEPs) are electrical signals generated at the visual cortex following visual stimulation. Flash VEPs (fVEPs) are produced by global retinal stimulation and are considered an objective measure of the integrity of the entire visual pathway. However, fVEP measurements are highly sensitive to external variables, making relative comparisons of the fVEP waveforms between the two eyes in the same individual challenging.
View Article and Find Full Text PDFEye (Lond)
December 2024
Center for Ophthalmic Bioinformatics, Cleveland Clinic, Cole Eye Institute, Cleveland, OH, USA.
Background/objectives: Patients with thyroid eye disease (TED) taking teprotumumab have reported audiologic symptoms as a side effect; however, limited real world data and large sample sizes have been utilized to evaluate this relationship.
Methods: A retrospective cohort study was created in TriNetX to identify patients with TED utilizing ICD-10, CPT, and Healthcare Common Procedure coding systems. TED patients with and without teprotumumab treatment were analysed with greedy one-to-one propensity matching.
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