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Optic Neuropathies Associated With Multiple Sclerosis (MS) and Neuromyelitis Optica Spectrum Disorders (NMO-SD)
Published in Vivek Lal, A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
MRI is considered the gold standard in the diagnosis of MS (refer to Annexure 5.1. – for Diagnostic Criteria of MS), but diagnostic confusion may occur in certain clinical scenarios (15). Newer neuro-ophthalmic tools like spectral domain optical coherence tomography (OCT) to measure the retinal nerve fiber layer (RNFL), ganglion cell inner plexiform layer (GCIP) may have a role as potential novel biomarkers of MS. Greater neuro-retinal loss may be a marker of greater disease activity (16). OCT is rather a novel biomarker to study the disease activity and progression of MS (17). Objective markers have the potential to explore such manifestations as subclinical involvement of the asymptomatic fellow eye. Structural changes in retinal layers other than the optic nerve fiber and ganglion cell layers have been observed. Variously known as “microcystic maculopathy” or “retrograde maculopathy,” there is controversy as to whether inner nuclear layer pathology represents a primary pathological process or the result of retrograde trans-synaptic changes. However, this change certainly reflects more advanced disease (17, 18).
Comparative Anatomy and Physiology of the Mammalian Eye
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
The retina is the most complex of all the ocular tissues. The classic description of the retina includes 10 layers which, from the outside in, are as follows (see Figures 17, 18, and 19): Retinal pigment epitheliumPhotoreceptor outer segmentsOuter limiting membraneOuter nuclear layerOuter plexiform layerInner nuclear layerInner plexiform layerGanglion cell layerNerve fiber layerInner limiting membrane
Impact of Retinal Stimulation on Neuromodulation
Published in Yu Chen, Babak Kateb, Neurophotonics and Brain Mapping, 2017
A large amount of retinal processing occurs at synaptic junctions. The outer plexiform layer of the retina is where electrical signals from the photoreceptors interact with bipolar cells. This outer layer includes dendrites from bipolar and horizontal cells as well as axons from photoreceptors. The inner nuclear layer contains the cell nuclei of horizontal, bipolar, and amacrine cells. The inner plexiform layer contains axons of bipolar cells, many types of amacrine cells, and dendrites of ganglion cells (Roska et al. 2006). A web of filtered excitatory and inhibitory signals in the inner plexiform layer detects motion and suppresses eye movements (Baccus 2007). The combination of those signals affects judgments in space and time (Kim et al. 2014a, Robinson 2014) and results in the final exiting signal from the ganglion cell.
A comparative study between the possible protective role of melatonin versus its combination with adipose derived-mesenchymal stem cells on experimentally induced diabetic retinopathy in adult male albino rats (Histological and immunohistochemical study)
Published in Ultrastructural Pathology, 2023
Samar Reda, Ghada A Elsammak, Tamer G Elsayed, Samar Abdelaziz Mostafa
H&E-stained sections from rat's retina of control group revealed the retinal layers from outside inwards; the retinal pigmented epithelium, photoreceptor layer, outer limiting membrane, outer nuclear layer, outer plexiform layer, inner nuclear layer, inner plexiform layer, ganglion cell layer, and inner limiting membrane (Figure 2a), the diabetic group (II) showed apparent decrease of retinal thickness. Vacuoles in photoreceptor layer and inner plexiform layer were observed. Focal widening of intercellular spaces of the inner nuclear layer and the outer nuclear layer were seen. GCL had some ganglionic cells with shrunken darkly stained nuclei. Congested blood vessel was also noticed (Figure 2b), the diabetic rats treated with melatonin (group III) showed partially preserved histological structure of the retinal layers. There were many vacuoles in photoreceptor layer. Ganglionic cells appeared with shrunken nuclei and vacuolated cytoplasm. Congested blood capillary in ganglion cell layer was noticed (Figure 2c), while the diabetic rats treated with melatonin and stem cells (group IV) showed structure nearly similar to the control group. There were some vacuoles in photoreceptor layer (Figure 2d).
Clinical reassessments and whole-exome sequencing uncover novel BEST1 mutation associated with bestrophinopathy phenotype
Published in Ophthalmic Genetics, 2022
Susmita Chowdhury, Roopam Duvesh, Manojkumar Kumaran, Rupa Anjanamurthy, Jayant Kumar, Ayyasamy Vanniarajan, Bharanidharan Devarajan, Periasamy Sundaresan
A 7-year-old Asian Indian male referred to our hospital in August 2016 with the chief complaint of decreased vision in both of his eyes noticed since the last few months. The best-corrected visual acuity (BCVA) of 0.30 logMAR (Snellen equivalent, 20/40) was noted in both the eyes. Anterior segment examination was normal for both eyes. Fundus examinations showed numerous faint subretinal vitelliform lesions and pigmentary changes surrounding the arcade, few foveal vitelliform lesions and spoke wheel-like pattern at the macula of both eyes. (Figure 1). Other peripheral retinal pathology ruled out in both eyes. Optical coherence tomography (OCT) evaluations of both eyes showed the presence of intra-retinal cystic changes at the level of inner nuclear layer (INL) and outer plexiform layer (OPL) (Figure 1).
Dose and time response study to develop retinal degenerative model of zebrafish with lead acetate
Published in Cutaneous and Ocular Toxicology, 2022
Histopathological images of control group depicted regular shaped retina and the seven retinal layers were typically organised. (Figure 1). Pigmented epithelial layer is present towards choroid layer. It consists of single layer of cells containing photosensitive pigmented granules. These pigmented granules consist of melanin pigment. Cell processes called villi are directed towards the photoreceptors. The second nuclear layer consists of three different types of cells i.e. bipolar cells, amacrine cells and horizontal cells. The horizontal cells are present closest to the receptors and amacrine cells are present towards ganglion cell layer. The synaptic junction of two nuclear layers is present in outer plexiform layer. The synaptic contacts of inner nuclear layer and ganglion cell layer have been observed in inner plexiform layer. Visual information passes through these synaptic junctions before leaving the eye.