Molecular Anatomy of the Vertebrate Eye
Marcel E. Nimni in Collagen, 1988
The retina is a thin, transparent membrane that rests on a single layer of pigmented epithelium. A cross section of the retina demonstrates then layers (Figure 9): pigment epithelium (1), rods and cones (2), external limiting membrane (3), outer nuclear layer (4), outer plexiform layer (5), inner nuclear layer (6), inner plexiform layer (7), ganglion cell layer (8), optic nerve fiber layer (9), and internal limiting membrane (10). The pigment epithelial cells lie on a thin basement membrane, Bruch’s membrane, which is a rather composite extracellular matrix. Bruch’s membrane consists of two basement membranes (one associated with the retinal pigmented epithelium and the other with the endothelium of the choriocapillaris), inner and outer fibrillar collagenous layers separated by a thin elastic layer. Bruch’s membrane provides structural support and a selective filtration barrier for transporting nutrients from the choriocapillaries to the inner portions of the retina. Rods and cones, so called because of their shape, are the light-sensitive cells of the retina; they lie in the outer layer in contact with the pigmented epithelium, which is vital for their metabolism. The visual pigments in the rods and cones absorb the light and transform the energy; this leads to a change in conductance of the cell membrane.
Level Set Methods in Segmentation of SDOCT Retinal Images
Ayman El-Baz, Jasjit S. Suri in Level Set Method in Medical Imaging Segmentation, 2019
As shown in Figure 5.2, the retina is a ten layered structure, viz., Nerve fiber layer (NFL), Ganglion cell layer (GCL), Inner plexiform layer (IPL), inner nuclear layer (INL), outer plexiform layer (OPL), outer nuclear layer (ONL), External limiting membrane (ELM), Ellipsoid zone (previously referred to as the IS/OS junction), Interdigitation zone, and Retinal pigment epithelium (RPE). Automatic detection of diabetic maculopathy from SDOCT retinal images is extremely important in analyzing the stage of diabetic retinopathy. Diabetic maculopathy is the condition of fluid being accumulated in between the retinal layers. As shown in Figure 5.3, SDOCT images provide more details about the intraretinal fluid and subretinal fluid present in the macula scan images.
Optical Coherence Tomography (Oct) and Fundus Fluorescein Angiography (FFA) in Neuro-Ophthalmology
Vivek Lal in A Clinical Approach to Neuro-Ophthalmic Disorders, 2023
She presented after 3 years with sudden-onset progressive loss of vision in both eyes (R>L) for 1 week. She presented to the neurology department, and the diagnosis of relapse of NMOSD was made. On examination, her best-corrected visual acuity (BCVA) was counting finger 1 m in the right eye and 20/160 in the left eye. Fundus examination (Figure 3A.3e and f) showed bilateral temporal disc pallor (R>L) in both eyes. OCT macula (Figure 3A.3g and h) showed some changes in the inner nuclear layer (red arrowhead) in the right eye with the otherwise normal foveal contour in both the eyes. GCA analysis (Figure 3A.3i and j) revealed bilateral thinning. The ganglion cell loss was more evident in the right eye (Figure 3A.3i) (darker the color, thinner is the ganglion cell layer). OCT pRNFL in the right eye (Figure 3A.3k) showed thinning of retinal nerve fiber layer of around the entire optic disc. In the left eye (Figure 3A.3l), only temporal and inferior pRNFL was thinned out.
Visual Pathway Degeneration in Chemotherapy-Related Neurotoxicity: A Review and Directions for Future Research
Published in Neuro-Ophthalmology, 2020
David E. Anderson, Sarah A. Holstein, Sachin Kedar
The neurosensory retina, being an outpost of the brain,22 offers an elegant model for studying neural circuits in health and disease.23 The retina is comprised of three nuclear layers containing cell bodies of distinct neuronal populations and two layers containing synaptic processes between each nuclear layer. The outer nuclear layer contains cell bodies of rods and cones, which selectively respond to varying degrees of light intensity and wavelengths (i.e. colours). The inner nuclear layer contains cell bodies of bipolar, horizontal, and amacrine cells, which selectively modulate neural activity transmitted by photoreceptors through excitatory and inhibitory interactions. The ganglion cell layer contains cell bodies of ganglion cells, which relay neural activity from the retina to the brain via ganglion cell axons within the retinal nerve fibre layer (RNFL) through the optic nerve. Synaptic processes between the photoreceptors and bipolar cells make up the outer plexiform layer, and synaptic processes between bipolar cells and ganglion cells make up the inner plexiform layer. Ophthalmic biomarkers have been developed and incorporated into clinical practice to evaluate the structure and function of these distributed retinal populations.
Neuroprotective Effect of Intravitreal Single-Dose Lithium Chloride after Optic Nerve Injury in Rats
Published in Current Eye Research, 2021
Moein Ala, Razieh Mohammad Jafari, Hossein Nematian, Mohammad Reza Ganjedanesh, Asieh Naderi, Mostafa Akbariani, Mehdi Sanatkar, Leila Satarian, Masoud Aghsaei Fard, Ahmad Reza Dehpour
To measure thickness of retinal, OCT was performed in different intervals (10, 30 days after trauma induction). OCT was performed after anesthetization of rats followed by restraining animals in front of the OCT device with dilated pupil. All central retina OCT measurements were performed with spectral domain OCT (Heidelberg Spectralis SD-OCT; Heidelberg Engineering, Heidelberg, Germany) on each rat eyes. For OCT, a fast line horizontal direction along the central retina was obtained after manually adjusting the position of a 20-diopter lens between rat eye and OCT camera to made retinal image more clearly. Most anatomic layers of the rat retina can be recognized with OCT image. Spectralis software was used for retinal layer segmentation. We reported the sum of the ganglion cell layer, the inner plexiform layer, and retinal nerve fiber layer. The RGC thickness data was recorded in three different locations of retinal line and the average was reported. Only images with good quality were used for data gathering.
Long-term corticosteroid-induced chronic glaucoma model produced by intracameral injection of dexamethasone-loaded PLGA microspheres
Published in Drug Delivery, 2021
MJ Rodrigo, D Garcia-Herranz, A Aragón-Navas, M Subias, T Martinez-Rincón, S Mendez-Martínez, MJ Cardiel, J García-Feijoo, J Ruberte, R Herrero-Vanrell, L Pablo, E Garcia-Martin, I Bravo-Osuna
For ganglion cell count, slides probed with mouse anti-Brn3a were incubated with biotinylated horse anti-mouse at 1:50 dilution (Vector Laboratories, Burlingame, CA, USA). They were then incubated with ABC-HRP (Thermo Fisher Scientific, Waltham Massachusetts, USA) at 1:50 dilution at room temperature. The sections were washed in PBS before and after every incubation. Finally, the sections were stained with DAB (Sigma-Aldrich) for 3 minutes and counterstained with Harris’ hematoxylin (Sigma-Aldrich) for 20 minutes at room temperature. Ganglion cells were counted in radial sections of the retina along 2 mm of a linear region of the ganglion cell layer corresponding to four areas, two on each side of the optic nerve head. The images were analyzed by an operator blinded to treatment groups.
Related Knowledge Centers
- Amacrine Cell
- Anatomy
- Axon
- Dendrite
- Eye
- Inner Plexiform Layer
- Retina
- Retinal Nerve Fiber Layer
- Retinal Ganglion Cell
- Laboratory Flask