scholarly journals USH2A-Related Retinitis Pigmentosa: Staging of Disease Severity and Morpho-Functional Studies

Diagnostics ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 213
Author(s):  
Benedetto Falsini ◽  
Giorgio Placidi ◽  
Elisa De Siena ◽  
Maria Cristina Savastano ◽  
Angelo Maria Minnella ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Usher Syndrome ◽  
Collaborative Study ◽  
Staging System ◽  
International Standards ◽  
Full Field ◽  
Functional Studies ◽  
Cumulative Score

Usher syndrome type 2A (USH2A) is a genetic disease characterized by bilateral neuro-sensory hypoacusia and retinitis pigmentosa (RP). While several methods, including electroretinogram (ERG), describe retinal function in USH2A patients, structural alterations can be assessed by optical coherence tomography (OCT). According to a recent collaborative study, RP can be staged considering visual acuity, visual field area and ellipsoid zone (EZ) width. The aim of this study was to retrospectively determine RP stage in a cohort of patients with USH2A gene variants and to correlate the results with age, as well as additional functional and morphological parameters. In 26 patients with established USH2A genotype, RP was staged according to recent international standards. The cumulative staging score was correlated with patients’ age, amplitude of full-field and focal flicker ERGs, and the OCT-measured area of sub-Retinal Pigment Epithelium (RPE) illumination (SRI). RP cumulative score (CS) was positively correlated (r = 0.6) with age. CS was also negatively correlated (rho = −0.7) with log10 ERG amplitudes and positively correlated (r = 0.5) with SRI. In USH2A patients, RP severity score is correlated with age and additional morpho-functional parameters not included in the international staging system and can reliably predict their abnormality at different stages of disease.

scholarly journals A review of recent developments in retinitis pigmentosa genetics, its clinical features, and natural course

2021 ◽  
Vol 9 (4) ◽  
Author(s):  
Eleftherios Loukovitis ◽  
Stoimeni Anastasia ◽  
Paris Tranos ◽  
Miltos Balidis ◽  
Solon Asteriadis ◽  
...  
Keyword(s):  
Retinitis Pigmentosa ◽  
Clinical Features ◽  
English Language ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Usher Syndrome ◽  
Retinal Dystrophy ◽  
Clinical Manifestations ◽  
Natural Course ◽  
Recent Developments

Background: Retinitis pigmentosa (RP), an inherited degenerative ocular disease, is considered the most common type of retinal dystrophy. Abnormalities of the photoreceptors, particularly the rods, and of the retinal pigment epithelium, characterizes this disease. The abnormalities progress from the midperiphery to the central retina. We here reviewed the developments in RP genetics in the last decade, along with its clinical features and natural course. Methods: The present review focused on articles in English language published between January 2008 and February 2020, and deposited in PubMed and Google Scholar databases. We searched for articles reporting on the clinical manifestations and genes related to both syndromic and non-syndromic RP. We screened and analyzed 139 articles, published in the last decade, referring to RP pathogenesis and identified, summarized, and highlighted the most significant genes implicated in either syndromic or non-syndromic RP pathogenesis, causing different clinical manifestations. Results: Recent literature revealed that approximately 80 genes are implicated in non-syndromic RP, and 30 genes in syndromic forms, such as Usher syndrome and Bardet‒Biedl syndrome (BBS). Moreover, it is estimated that 27 genes are implicated in autosomal dominant RP (adRP), 55 genes in autosomal recessive RP (arRP), and 6 genes in X-linked RP (xlRP), causing different RP phenotypes. Characteristically, RHO is the most prevalent adRP- and arRP-causing gene, and RPGR the most common xlRP-causing gene. Other important genes are PRPH2, RP1, CRX, RPE65, ABCA4, CRB1, and USH2Α. However, different phenotypes can also be caused by mutations in the same gene. Conclusions: The genetic heterogeneity of RP necessitates further study to map the exact mutations that cause more severe forms of RP, and to develop and use appropriate genetic or other effective therapies in future.

scholarly journals Pathophysiological features of the visual cycle, cascade and metabolic pathways in retinitis pigmentosa

2021 ◽  
Vol 14 (1) ◽  
pp. 80-88
Author(s):  
M. E. Weener ◽  
D. S. Atarshchikov ◽  
V. V. Kadyshev ◽  
I. V. Zolnikova ◽  
A. M. Demchinsky ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Literature Review ◽  
Retinitis Pigmentosa ◽  
Metabolic Pathways ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Visual Signal ◽  
Visual Cycle ◽  
Target Treatment ◽  
Interphotoreceptor Matrix

This literature review offers a detailed description of the genes and proteins involved in pathophysiological processes in isolated retinitis pigmentosa (RP). To date, 84 genes and 7 candidate genes have been described for non-syndromic RP. Each of these genes encodes a protein that plays a role in vital processes in the retina and / or retinal pigment epithelium, including the cascade of phototransduction (transmission of the visual signal), the visual cycle, ciliary transport, the environment of photoreceptor cilia and the interphotoreceptor matrix. The identification and study of pathophysiological pathways affected in non-syndromic RP is important for understanding the main pathogenic ways and developing approaches to target treatment.

Diffuse Pigmented Lesions in the Outer Retina: An Unusual Fundus Appearance

2019 ◽  
Vol 4 (3) ◽  
pp. 243-247
Author(s):  
Matthew D. Benson ◽  
Uriel Rubin ◽  
Marvi Cheema ◽  
Ian M. MacDonald ◽  
Matthew T.S. Tennant ◽  
...  
Keyword(s):  
Phenotypic Diversity ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Retinal Dystrophy ◽  
Full Field ◽  
Panel Testing ◽  
Pigmented Lesions ◽  
Hereditary Retinal Dystrophy ◽  
Ultrasound Findings ◽  
Chest X Ray

Purpose: This report describes and provides a differential diagnosis for a patient with unusual bilateral retinal pigmented lesions. Methods: A 40-year-old woman was found to have multiple flat, gray lesions scattered across her fundi, becoming larger and more confluent toward the periphery. There were small drusenlike deposits in her foveae. The hyperpigmented lesions demonstrated hypoautofluorescence with thickening of the retinal pigment epithelium and disruption of the overlying layers on optical coherence tomography (OCT). Full-field electroretinography revealed generalized reduced a- and b-wave amplitudes. Results: Chest x-ray, breast ultrasound, mammography, and pelvic ultrasound findings were negative for malignant etiologic factors. Panel testing results for hereditary retinal dystrophy were negative. Conclusions: Although the clinical and OCT appearance of the lesions is similar to congenital grouped pigmentation, the symmetric and bilateral nature of ocular findings coupled with electroretinographic changes suggest a possible retinal dystrophy. This case adds to the phenotypic diversity of pigmented fundus lesions.

A PRPH2 gene variant detected in retinitis punctata albescens with congenital hypertrophy of the retinal pigment epithelium

2020 ◽  
pp. 112067212096202
Author(s):  
Aowang Qiu ◽  
Yan Yu ◽  
Junlong Huang ◽  
Qinghuai Liu ◽  
Yannis M Paulus ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Cone Photoreceptor ◽  
Blurred Vision ◽  
Full Field ◽  
Photoreceptor Outer Segments ◽  
Pigmented Lesions ◽  
Retinitis Punctata Albescens ◽  
Congenital Hypertrophy

Retinitis punctata albescens (RPA) is generally diagnosed by the presence of numerous clusters of white punctate lesions in the retina that progress over time and are related to several gene variants. The multifocal variant of congenital hypertrophy of the retinal pigment epithelium (CHRPE) is characterized by multiple, grouped, sharply circumscribed, pigmented spots. The PRPH2 gene encodes a photoreceptor-specific glycoprotein, which is essential for the morphogenesis of rod and cone photoreceptor outer segments. A 39-year-old Chinese female with nyctalopia, complained about blurred vision, presented a unique co-existing feature of RPA and CHRPE. Dilated fundus exam demonstrated numerous porcelain white discrete dots in both eyes and multiple, small, flat clusters of round brown to black pigmented lesions in the left eye. The full field electroretinography (ERG) showed decreased responses after standard dark adaptation and normal b-wave amplitudes after a long (4-h) dark-adapted period. A heterozygous PRPH2 splicing variant was detected in the proband. In addition, the same variant was found in her mother, her son, and her daughter. We describe a PRPH2 variant in a rare case of RPA associated with multifocal CHRPE of the same individual.

scholarly journals The Role of the Endothelin System in the Vascular Dysregulation Involved in Retinitis Pigmentosa

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Francesco Saverio Sorrentino ◽  
Claudio Bonifazzi ◽  
Paolo Perri
Keyword(s):  
Blood Flow ◽  
Retinitis Pigmentosa ◽  
Vascular System ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Ocular Blood Flow ◽  
The Body ◽  
Vascular Dysregulation ◽  
Endothelin System

Retinitis pigmentosa is a clinical and genetic group of inherited retinal disorders characterized by alterations of photoreceptors and retinal pigment epithelium leading to a progressive concentric visual field restriction, which may bring about severe central vision impairment. Haemodynamic studies in patients with retinitis pigmentosa have demonstrated ocular blood flow abnormalities both in retina-choroidal and in retroocular vascular system. Moreover, several investigations have studied the augmentation of endothelin-1 plasma levels systemically in the body and locally in the eye. This might account for vasoconstriction and ischemia, typical in vascular dysregulation syndrome, which can be considered an important factor of reduction of the ocular blood flow in subjects affected by retinitis pigmentosa.

Transplantation of intact sheets of fetal neural retina with its retinal pigment epithelium in retinitis pigmentosa patients

2002 ◽  
Vol 133 (4) ◽  
pp. 544-550 ◽  
Author(s):  
Norman D Radtke ◽  
Magdalene J Seiler ◽  
Robert B Aramant ◽  
Heywood M Petry ◽  
Diane J Pidwell
Keyword(s):  
Retinal Pigment Epithelium ◽  
Retinitis Pigmentosa ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Neural Retina

Expanding the retinal phenotype of RP1: from retinitis pigmentosa to a novel and singular macular dystrophy

2019 ◽  
Vol 104 (2) ◽  
pp. 173-181 ◽  
Author(s):  
Marina Riera ◽  
Víctor Abad-Morales ◽  
Rafael Navarro ◽  
Sheila Ruiz-Nogales ◽  
Pilar Méndez-Vendrell ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Retinitis Pigmentosa ◽  
Pigment Epithelium ◽  
Fundus Autofluorescence ◽  
Retinal Pigment ◽  
Retinal Dystrophy ◽  
Macular Dystrophy ◽  
Nucleotide Polymorphisms ◽  
Autofluorescence Imaging ◽  
New Genotype

PurposeThis study aimed to identify the underlying genetic cause(s) of inherited retinal dystrophy (IRD) in 12 families of Kuwaiti origin affected by macular dystrophy and four Spanish patients affected by retinitis pigmentosa (RP).MethodsClinical diagnoses were based on standard ophthalmic evaluations (best-corrected visual acuity, retinography, fundus autofluorescence imaging, optical coherence tomography, electroretinography and visual field tests). Panel-based whole exome sequencing was used to simultaneously analyse 224 IRD genes in one affected member of each family. The putative causative variants were confirmed by Sanger sequencing and cosegregation analyses. Haplotype analysis was performed using single nucleotide polymorphisms.ResultsA homozygous missense mutation c.606C>A (p.Asp202Glu) in RP1 was found to be the molecular cause of IRD in all 12 families from Kuwait. These patients exhibited comparable symptoms, including progressive decline in visual acuity since adolescence. Fundus autofluorescence images revealed bilateral macular retinal pigment epithelium disturbances, with neither perimacular flecks nor peripheral alterations. A shared haplotype spanning at least 1.1 Mb was identified in all families, suggesting a founder effect. Furthermore, RP1 variants involving nonsense and/or frameshifting mutations (three of them novel) were identified in three Spanish autosomal-recessive RP families and one dominant RP pedigree.ConclusionThis study describes, for the first time, a macular dystrophy phenotype caused by an RP1 mutation; establishing a new genotype-phenotype correlation in this gene, expanding its mutation spectrum and further highlighting the clinical heterogeneity associated with IRD.

scholarly journals Missense Mutations in a Retinal Pigment Epithelium Protein, Bestrophin-1, Cause Retinitis Pigmentosa

2009 ◽  
Vol 85 (5) ◽  
pp. 581-592 ◽  
Author(s):  
Alice E. Davidson ◽  
Ian D. Millar ◽  
Jill E. Urquhart ◽  
Rosemary Burgess-Mullan ◽  
Yusrah Shweikh ◽  
...  
Keyword(s):  
Retinal Pigment Epithelium ◽  
Retinitis Pigmentosa ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Missense Mutations

Noninvasive recording and response characteristics of the rat dc-electroretinogram

2002 ◽  
Vol 19 (6) ◽  
pp. 693-701 ◽  
Author(s):  
NEAL S. PEACHEY ◽  
J. BRETT STANTON ◽  
ALAN D. MARMORSTEIN
Keyword(s):  
Light Exposure ◽  
Pigment Epithelium ◽  
Retinal Pigment ◽  
Experimental Manipulation ◽  
Sprague Dawley ◽  
Active Electrode ◽  
Slow Potential ◽  
Full Field ◽  
Stimulus Response ◽  
Response Characteristics

In response to light, the retinal pigment epithelium (RPE) generates a series of potentials that can be recorded using the dc-electroretinogram (dc-ERG). As these potentials can be related to specific cellular events, they provide information about RPE function and how that may be altered by disease or experimental manipulation. The purposes of the present study were to define a noninvasive means for recording the rat dc-ERG, to use this to define the stimulus–response properties of the major components, and to relate these results to measures of the rat electrooculogram (EOG). Parallel studies were conducted in two strains of rats (Long-Evans, LE; Sprague-Dawley, SD) that are commonly used in vision research. Rats were sedated with ketamine/xylazine and placed on a heating pad. Ag/AgCl wire electrodes were bridged with capillary tubes filled with Hanks balanced salt solution. The active electrode was placed in contact with the corneal surface and referenced to a second electrode placed within the orbit. The dc-ERG signal was amplified (dc-100 Hz), digitized, and stored offline. The duration of full-field flash stimuli was controlled using a mechanical shutter and flash luminance was controlled with neutral density filters. EOGs were recorded using subdermal platinum needle electrodes placed near the eye. In response to a 5-min light exposure, the dc-ERG of LE and SD rats included a distinct b-wave, after potential, c-wave, fast oscillation, and a slow potential of positive polarity the characteristics of which are consistent with a light peak.

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