Comparative analysis of cell distribution in the pigment epithelium and the visual cell layer of chimaeric mice

Development ◽  
1976 ◽  
Vol 36 (2) ◽  
pp. 425-430
Author(s):  
S. Sanyal ◽  
G. H. Zeilmaker
Keyword(s):  
Comparative Analysis ◽  
Cell Layer ◽  
Pigment Epithelium ◽  
Spatial Relation ◽  
Visual Cell ◽  
Cell Distribution ◽  
Retinal Layers

In chimaeras of both rdrdCC↔ + + cc and rdrdcc↔ + + CC combinations two types of distribution were observed. In a majority of the chimaeras both retinal layers were chimaeric; whereas in a few cases the pigment epithelium was chimaeric but the visual cell layer was made of + + cells only. No spatial relation was observed in the distribution of the cells in the two layers. The two eyes of the individuals were nearly always identical with regard to occurrence of chimaerism in the two layers. The findings are discussed in the light of the possible site and mode of expression of the rd gene.

Retinal development and visual sensitivity of young Pacific sockeye salmon (Oncorhynchus nerka)

1996 ◽  
Vol 199 (4) ◽  
pp. 869-882 ◽  
Author(s):  
I N Flamarique ◽  
C W Hawryshyn
Keyword(s):  
Rainbow Trout ◽  
Sockeye Salmon ◽  
Cell Layer ◽  
Retinal Development ◽  
Pigment Epithelium ◽  
Outer Nuclear Layer ◽  
Retinal Pigment ◽  
Visual Sensitivity ◽  
Polarization Sensitivity ◽  
Visual Cell

The development of photoreceptor cell types and the visual sensitivity of young sockeye salmon were examined. In contrast to previous findings from rainbow trout, rod outer segments were observed in the embryo 1.5 weeks before hatching. At this stage, a full square mosaic with accessory corner cones was visible in the central retina. Post-hatching retinal development is similar to that of other fish species. During the first 11 months of development, the fibrous and interplexiform layers, the outer nuclear layer, the visual cell layer and the retinal pigment epithelium thicken. The ganglion cell layer and the inner nuclear layer regress. In addition, the mean diameter of the cones increases, with that of double cones increasing faster than that of either of the single cone types. As is the case for other salmonids, the density of accessory corner cones diminishes after smoltification (a developmental stage in salmonids). The retina of smolts exhibits a full square mosaic pattern in some peripheral areas and near the central embryonic fissure. However, unlike findings from rainbow trout, compound action potential recordings from the optic nerve of smolt sockeye reveal the presence of four cone mechanisms with sensitivity maxima at 380 (ultraviolet), 425 (short), 520 (middle) and 635 nm (long wavelength). There is also a rod mechanism with maximum sensitivity around 530 nm. Smolts also exhibit polarization sensitivity to 380 nm light under a white crepuscular background.

2247-PUB: Comparative Analysis of the Thickness of Inner Retinal Layers among African Immigrants Based on Their Status of Glucose Tolerance

Diabetes ◽  
2019 ◽  
Vol 68 (Supplement 1) ◽  
pp. 2247-PUB
Author(s):  
CHRISTOPHER K. HWANG ◽  
ELVIRA AGRON ◽  
ANNE E. SUMNER ◽  
SARA M. BRIKER ◽  
JESSICA Y. ADUWO ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Glucose Tolerance ◽  
African Immigrants ◽  
Retinal Layers

scholarly journals Focal Choroidal Excavation in a Case of Choroidal Osteoma Associated with Choroidal Neovascularization

2020 ◽  
Author(s):  
Mahdieh Azimizadeh ◽  
Seyedeh Maryam Hosseini ◽  
Esmaeil Babaei
Keyword(s):  
Choroidal Neovascularization ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Subretinal Fluid ◽  
Retinal Hemorrhage ◽  
Retinal Layers ◽  
Choroidal Osteoma ◽  
Focal Choroidal Excavation ◽  
Neurosensory Retina ◽  
The Right

Purpose: To report a case of choroidal osteoma associated with reactivation of choroidal neovascularization (CNV) and development of focal choroidal excavation (FCE). Case Report: A 34-year-old woman with choroidal osteoma complicated by CNV in the right eye for two years presented with deterioration of visual acuity in her right eye. A small retinal hemorrhage accompanied by subretinal fluid (SRF) was seen in the macular area of the right eye. Optical coherence tomography (OCT) showed that the inner retina was intact, and the outer retinal layers had outward displacement. SRF and a wedge-shaped choroidal depression were also seen. This choroidal excavation was not present on previous OCT images. The integrity of the inner retinal layers was maintained, and an optically clear space was present between the neurosensory retina and the retinal pigment epithelium. Conclusion: Choroidal osteoma can be complicated by CNV and FCE could occur as a consequence. Again, FCE can lead to CNV development. This cascade can deteriorate vision and sometime lead to permanent visual loss.

scholarly journals Outer Retinal Layers’ Thickness Changes in relation to Age and Choroidal Thickness in Normal Eyes

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Mona Kamal Abdellatif ◽  
Yasser Abdelmaguid Mohamed Elzankalony ◽  
Ahmed Abdelmonsef Abdelhamid Ebeid ◽  
Weam Mohamed Ebeid
Keyword(s):  
Choroidal Thickness ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Enhanced Depth Imaging ◽  
Old Patients ◽  
Retinal Layers ◽  
Age Related ◽  
Significant Difference ◽  
Group 3 ◽  
Sd Oct

Purpose. To identify and correlate age-related changes in outer retinal layers’ thickness and choroidal thickness (CT) in the normal eyes using spectral-domain optical coherence tomography (SD-OCT) and to investigate factors affecting these changes. Study Design. Observational cross-sectional study. Subjects and Methods. We studied 125 healthy Egyptians between 20 and 79 years old. Patients were divided into 3 groups: group 1 (20–40 years), group 2 (40–60 years), and group 3 (>60 years). All patients had full ophthalmic examination. SD-OCT was done to measure the 9 ETDRS macular grid sectors of retinal pigment epithelium and photoreceptor outer segment (RPE-OS), outer nuclear layer and photoreceptor inner segment (ONL-IS), and choroidal thickness (CT) (by enhanced depth imaging). Results. RPE-OS was significantly thinner in group 3 than in the other 2 groups (central: P<0.001). Moreover, the 3 groups were significantly different from each other regarding the CT (central: P<0.001); significant thinning was noticed in the choroid with age. The 3 groups did not show significant difference concerning the ONL-IS thickness. RPE-OS and CT showed statistically significant negative correlation with age (central RPE-OS: r = −0 C.345, P<0.001, and central CT: r = −0.725, P<0.001) while ONL-IS showed statistically nonsignificant correlation with age (central ONL-IS: r = −0.08, P=0.376). Multiple regression analysis revealed that the most important determinant of central 1 mm RPE-OS thickness in this study was age (β = −0.087, P=0.010) rather than choroidal thinning (β = 0.001, P=0.879). Conclusion. RPE-OS layer thickness shows significant thinning with increasing age, and with decrease in CT, however, age is the most determinant factor of this thinning.

scholarly journals In vivo optical biopsy of choroidal osteoma: a swept source optical coherence tomography–based tumor characterization

2020 ◽  
Vol 12 ◽  
pp. 251584142092274 ◽  
Author(s):  
Shorya Vardhan Azad ◽  
Vinod Kumar ◽  
Rohan Chawla ◽  
Bibhuti Kashyap ◽  
Shreyas Temkar ◽  
...  
Keyword(s):  
Optical Coherence Tomography ◽  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Signal Transmission ◽  
Retinal Pigment ◽  
Optical Coherence ◽  
Choroidal Neovascular Membrane ◽  
Swept Source ◽  
Retinal Layers ◽  
Choroidal Osteoma

Objective: To study tumor characteristics of choroidal osteoma by swept source optical coherence tomography. Methods: A retrospective case series done at tertiary referral center in northern India. All patients diagnosed with choroidal osteoma examined on swept source optical coherence tomography were included. Swept source optical coherence tomography images were analyzed for integrity of retinal layers—intraretinal layers, outer retinal layers (photoreceptor), retinal pigment epithelium, and contour abnormalities. Choroidal changes assessed were tumor attributes such as shape, depth of choroidal involvement, tumor mass reflectivity pattern, tumor vascularity, and evolutionary structural abnormalities such as deossification, focal depressions, or choroidal neovascular membrane. Results: A total of 15 eyes of 11 patients were analyzed. Seven of 11 patients were females. Mean age of presentation was approximately 26 years. Tumor was large in nine cases (>7.5 mm). Deossification was seen in 12 eyes. Inner and outer retinal integrity was maintained in 7 and 2 eyes, respectively. Most common internal tumor reflectivity pattern seen was a lamellar appearance (12/15). Increased signal transmission to choroid and focal area of deep excavation was present in 11 and 4 eyes, respectively. Osteoclastic activity was noted in 12 eyes. Choroidal neovascular membrane was seen in 6 eyes. Small lesions showed lamellar pattern of tumor reflectivity with preservation of retinal pigment epithelium and overlying retina. Larger tumors were deossified with 6 irregular tumor contour, disorganization of the outer retina, increased signal transmission to choroid, and areas of osteoclastic activity. Conclusion: Swept source optical coherence tomography was helpful in assessing tumor attributes and predicting the different timelines in tumor evolution.

scholarly journals RENEWAL OF FATTY ACIDS IN THE MEMBRANES OF VISUAL CELL OUTER SEGMENTS

1974 ◽  
Vol 61 (2) ◽  
pp. 327-343 ◽  
Author(s):  
Carol Bibb ◽  
Richard W. Young
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Vitamin A ◽  
Palmitic Acid ◽  
Outer Segment ◽  
Pigment Epithelium ◽  
Radioactive Material ◽  
Visual Cell ◽  
Outer Segments ◽  
Acid Exchange

The renewal of fatty acids in the visual cells and pigment epithelium of the frog retina was studied by autoradiographic analysis of animals injected with tritiated palmitic, stearic, or arachidonic acids. Most of the radioactive material could be extracted from the retina with chloroform-methanol, indicating that the fatty acids had been esterified in lipids. Analysis of the extracts, after injection of [3H]palmitic acid, revealed that the radioactivity was predominantly in phospholipid. Palmitic acid was initially concentrated in the pigment epithelium, particularly in oil droplets which are storage sites for vitamin A esterified with fatty acid. The cytoplasm, but not the nucleus of these cells, was also heavily labeled. Radioactive fatty acid was bound immediately to the visual cell outer segment membranes, including detached rod membranes which had been phagocytized by the pigment epithelium. This is believed to be due to fatty acid exchange in phospholipid molecules already situated in the membranes. Gradually, the concentration of radioactive material in the visual cell outer segment membranes increased, apparently as a result of the addition of new phospholipid molecules, possibly augmented by the transfer from the pigment epithelium of esterified vitamin A. Injected fatty acid became particularly concentrated in new membranes which are continually assembled at the base of rod outer segments. This localized concentration was short-lived, apparently due to the rapid renewal of fatty acid. The results support the conclusion that rods renew the lipids of their outer segments by membrane replacement, whereas both rods and cones renew the membrane lipids by molecular replacement, including fatty acid exchange and replacement of phospholipid molecules in existing membranes.

scholarly journals THE ROLE OF THE PIGMENT EPITHELIUM IN THE ETIOLOGY OF INHERITED RETINAL DYSTROPHY IN THE RAT

1971 ◽  
Vol 49 (3) ◽  
pp. 664-682 ◽  
Author(s):  
Dean Bok ◽  
Michael O. Hall
Keyword(s):  
Cell Death ◽  
Outer Segment ◽  
Pigment Epithelium ◽  
Retinal Dystrophy ◽  
Visual Cell ◽  
Sprague Dawley ◽  
Inherited Retinal Dystrophy ◽  
Rcs Rats ◽  
Electron Microscopes ◽  
And Control

Visual cell outer segment renewal was studied in eyes of mutant Royal College of Surgeons (RCS) and Sprague-Dawley (control) rats by a combination of microscopy and radioautography with the light and electron microscopes. RCS and control rats were injected with amino acids-3H at 11 days of age. Radioactive rod outer segment discs were assembled at the outer segment base from radioactive proteins synthesized in the rod inner segments. In controls, all radioactive discs assembled at 11 days of age were displaced the length of the outer segments, removed from outer segment tips, and phagocytized by the pigment epithelium by 8 days after injection. In the RCS rats, disc assembly and displacement resembled controls for the first 3 days after injection. However, as disc assembly continued for some time thereafter, a layer of labeled, disorganized, lamellar debris accumulated between the outer segment tips and the pigment epithelium. The buildup of debris was accompanied by visual cell death. At no time during the study was there evidence for phagocytic activity by the pigment epithelium. 61 days after injection, the layer of debris was the only heavily radioactive component in the retina. In the retina of RCS rats, the outer segment renewal mechanism malfunctions because the pigment epithelium does not fulfill its normal phagocytic role. The end result is visual cell death and blindness.

Visual Capability of the Weakly Electric Fish Apteronotus albifrons as Revealed by a Modified Retinal Flat-Mount Method

2015 ◽  
Vol 86 (2) ◽  
pp. 122-130 ◽  
Author(s):  
Tomo Takiyama ◽  
Valdir Luna da Silva ◽  
Daniel Moura Silva ◽  
Sawako Hamasaki ◽  
Masayuki Yoshida
Keyword(s):  
Ganglion Cell ◽  
Ganglion Cells ◽  
Pigment Epithelium ◽  
The Body ◽  
Weakly Electric Fish ◽  
Resolving Power ◽  
Cell Distribution ◽  
High Acuity ◽  
Continuous Sheet ◽  
Cell Densities

Apteronotus albifrons (Gymnotiformes, Apteronotidae) is well known to have a sophisticated active electrosense system and is commonly described as having poor vision or being almost blind. However, some studies on this species suggest that the visual system may have a role in sensing objects in the environment. In this study, we investigated the visual capabilities of A. albifrons by focusing on eye morphology and retinal ganglion cell distribution. The eyes were almost embedded below the body surface and pigmented dermal tissue covered the peripheral regions of the pupil, limiting the direction of incoming light. The lens was remarkably flattened compared to the almost spherical lenses of other teleosts. The layered structure of the retina was not well delineated and ganglion cells did not form a continuous sheet of cell bodies. A newly modified retinal flat-mount method was applied to reveal the ganglion cell distribution. This method involved postembedding removal of the pigment epithelium of the retina for easier visualization of ganglion cells in small and/or fragile retinal tissues. We found that ganglion cell densities were relatively high in the periphery and highest in the nasal and temporal retina, although specialization was not so high (approx. 3:1) with regard to the medionasal or mediotemporal axis. The estimated highest possible spatial resolving power was around 0.57 and 0.54 cycles/degree in the nasal and temporal retina, respectively, confirming the lower importance of the visual sense in this species. However, considering the hunting nature of A. albifrons, the relatively high acuity of the caudal visual field in combination with electrolocation may well be used to locate prey situated close to the side of the body.

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