Aim: To evaluate the effect of long-term weightlessness on retina and optic nerve in tail-suspension (TS) rats.
Methods: A stimulated weightlessness model was established by suspending rats' tail. After 12wk, the ultrastructure and the number of optic nerve axons were observed by transmission electron microscope. The number of survival retinal ganglion cells (RGCs) was calculated by fluorescent gold retrograde labeling. Retina cells apoptosis was detected by TUNEL staining. The function of optic nerve and retina was evaluated by the visual evoked potential (VEP) and oscillatory potentials (Ops).
Results: The optic nerve axons were swollen and sparsely aligned, and the lamellar separation and myelin disintegration occurred after 12wk in TS rats. The density of optic nerve axons was 32.23±3.92 (vs 37.43±4.13, P=0.0145), the RGCs density was 1645±46 cells/mm(2) (vs 1867±54 cells/mm(2) P=0.0000), the incidence rate of retinal cells apoptosis was 5.38%±0.53% (vs 4.75%±0.54%, P=0.0238), the amplitude of VEP-P100 was 15.43±2.14 µV (vs 17.67±2.17 µV, P=0.0424), the latency of VEP-P100 was 69.05±5.34ms (vs 62.43±4.87ms P=0.0143) and the sum amplitude of Ops was 81.05±8.34 µV (vs 91.67±10.21 µV, P=0.0280) in TS group and the control group, respectively.
Conclusion: Long-term weightlessness can induce the ultrastructural changes and functional depress of the optic nerve, as well as retinal cell damages in TS rats.
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http://dx.doi.org/10.18240/ijo.2016.06.06 | DOI Listing |
Am J Emerg Med
December 2024
Department of Neurology, University of Wisconsin-Madison, Madison, WI, USA. Electronic address:
Objectives: While lumbar puncture (LP) remains gold standard for assessing intracranial pressure (ICP), LP can be difficult to perform and lead to complications. Noninvasive correlations for elevated ICP via ocular ultrasound (OUS) have shown mixed results. The primary objective of this study is to identify the frequency and test characteristics of the crescent sign on OUS for elevated ICP.
View Article and Find Full Text PDFAlzheimers Dement
December 2024
Center for Neurodegenerative Disease Research, Department of Pathology and Laboratory Medicine, University of Pennsylvania, Perelman School of Medicine, Philadelphia, PA, USA.
Background: Glaucoma is characterized by progressive optic nerve degeneration that results in irreversible blindness, and it can be considered a neurodegenerative disorder of both the eye and the brain. Increasing evidence suggest that glaucoma shares some common neurodegenerative pathways with Frontotemporal Lobar Degeneration (FTLD), Amyotrophic Lateral Sclerosis (ALS), and Alzheimer's Disease (AD) among others. Interestingly, a recent study revealed the presence of abnormal TAR DNA-binding protein 43 (TDP-43) inclusions and aggregates in retinal ganglion cells and other retinal cell types in FTLD-TDP patients; however, the significance of this pathology and its impact on retinal function and optical nerve integrity is unknown.
View Article and Find Full Text PDFCureus
December 2024
Department of Ophthalmology, Xi'an No. 3 Hospital, the Affiliated Hospital of Northwest University, Xi'an, CHN.
Choroidal nevus is the most common intraocular tumor, and most cases are benign and have no symptoms. However, choroidal nevus carries a low risk for transformation into melanoma, which is a highly aggressive and deadly cancer. In this case report, we present a male patient with blurred vision in his left eye for six months.
View Article and Find Full Text PDFExpert Rev Med Devices
January 2025
Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, China.
Objective: To explore the impact of glaucoma on the retinal nerve fiber layer (RNFL) optical density ratio (ODR) by volumetric optical coherence tomography (OCT) under different analytical radii.
Methods: Twenty-five eyes identified as healthy and 57 eyes with a glaucoma diagnosis (23 mild and 34 moderate-advanced cases) underwent volumetric OCT scans centered at the optic nerve head. Cross-sectional images were obtained through 5 distinct analytical circles with varying radii.
BMC Ophthalmol
January 2025
Department of Ophthalmology, University of Health Sciences, Izmir Bozyaka Education and Research Hospital, Bahar Mah. Saim Çıkrıkcı Cad No: 59, Karabağlar, Turkey.
Background: The aim of the present study was to compare the rates of change in Ganglion Cell- Inner Plexiform Layer (GCIPL) and Retinal Nerve Fiber Layer (RNFL) thickness, as measured by Optical Coherence Tomography (OCT) Guided Progression Analysis (GPA) program in control group, Primary Open Angle Glaucoma (POAG) and Pseudoexfoliation Glaucoma (PXG) eyes.
Methods: 60 POAG and 60 PXG patients and 30 control group patients were included in the study. Patients diagnosed with glaucoma were divided into two groups as mild (Mean deviation (MD) > -6.
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