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Beigi YZ, Lanjanian H, Fayazi R, Salimi M, Hoseyni BHM, Noroozizadeh MH, Masoudi-Nejad A. Heterogeneity and molecular landscape of melanoma: implications for targeted therapy. MOLECULAR BIOMEDICINE 2024; 5:17. [PMID: 38724687 PMCID: PMC11082128 DOI: 10.1186/s43556-024-00182-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 04/08/2024] [Indexed: 05/12/2024] Open
Abstract
Uveal cancer (UM) offers a complex molecular landscape characterized by substantial heterogeneity, both on the genetic and epigenetic levels. This heterogeneity plays a critical position in shaping the behavior and response to therapy for this uncommon ocular malignancy. Targeted treatments with gene-specific therapeutic molecules may prove useful in overcoming radiation resistance, however, the diverse molecular makeups of UM call for a patient-specific approach in therapy procedures. We need to understand the intricate molecular landscape of UM to develop targeted treatments customized to each patient's specific genetic mutations. One of the promising approaches is using liquid biopsies, such as circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA), for detecting and monitoring the disease at the early stages. These non-invasive methods can help us identify the most effective treatment strategies for each patient. Single-cellular is a brand-new analysis platform that gives treasured insights into diagnosis, prognosis, and remedy. The incorporation of this data with known clinical and genomics information will give a better understanding of the complicated molecular mechanisms that UM diseases exploit. In this review, we focused on the heterogeneity and molecular panorama of UM, and to achieve this goal, the authors conducted an exhaustive literature evaluation spanning 1998 to 2023, using keywords like "uveal melanoma, "heterogeneity". "Targeted therapies"," "CTCs," and "single-cellular analysis".
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Affiliation(s)
- Yasaman Zohrab Beigi
- Laboratory of System Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Hossein Lanjanian
- Software Engineering Department, Engineering Faculty, Istanbul Topkapi University, Istanbul, Turkey
| | - Reyhane Fayazi
- Laboratory of System Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | - Mahdieh Salimi
- Department of Medical Genetics, Institute of Medical Biotechnology, National Institute of Genetic Engineering and Biotechnology (NIGEB), Tehran, Iran
| | - Behnaz Haji Molla Hoseyni
- Laboratory of System Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran
| | | | - Ali Masoudi-Nejad
- Laboratory of System Biology and Bioinformatics (LBB), Institute of Biochemistry and Biophysics, University of Tehran, Tehran, Iran.
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Merle DA, Kohl S, Kempf M, Stingl K, Kowalski M, Kühlewein L. Diagnosis of Incomplete Congenital Stationary Night Blindness in a 2-year-old boy. Klin Monbl Augenheilkd 2024. [PMID: 38653459 DOI: 10.1055/a-2255-8098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/25/2024]
Affiliation(s)
- David A Merle
- Department of Ophthalmology, University Hospital Tübingen, Germany
| | - Susanne Kohl
- Department of Ophthalmology, University Hospital Tübingen, Germany
| | - Melanie Kempf
- Department of Ophthalmology, University Hospital Tübingen, Germany
| | - Katarina Stingl
- Department of Ophthalmology, University Hospital Tübingen, Germany
| | - Martin Kowalski
- Department of Ophthalmology, University Hospital Tübingen, Germany
| | - Laura Kühlewein
- Department of Ophthalmology, University Hospital Tübingen, Germany
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Wei X, Li H, Wu S, Zhu T, Sui R. Genetic analysis and clinical features of three Chinese patients with Oguchi disease. Doc Ophthalmol 2023; 146:17-32. [PMID: 36417138 DOI: 10.1007/s10633-022-09910-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Accepted: 10/27/2022] [Indexed: 11/24/2022]
Abstract
BACKGROUND Oguchi disease is a rare autosomal recessive form of congenital stationary night blindness caused by disease-causing variants in the rhodopsin kinase gene (GRK1) or the arrestin gene (SAG). Our study aims to describe the clinical features and identify the genetic defects for three Chinese patients with Oguchi disease. METHODS We conducted detailed ophthalmologic examinations for three patients from three unrelated non-consanguineous Chinese families. Targeted next-generation sequencing (targeted NGS) and copy number variations (CNVs) analysis were applied to screen pathogenic variants. Sanger sequencing validation, quantitative real-time PCR (qPCR), and segregation analysis were further performed for confirmation. Subsequently, a combined genetic and structural biology approach was used to infer the likely functional consequences of novel variants. RESULTS All three patients presented with typical clinical features of Oguchi disease, including night blindness, characteristic fundus appearance (Mizuo-Nakamura phenomenon), attenuated rod responses, and negative ERG waveforms. Their visual acuity and visual field were normal. Genetic analysis revealed two pathogenic variants in SAG and four pathogenic variants in GRK1. Patient 1 was identified to harbor compound heterozygous SAG variants c.874C > T (p.R292*) and exon2 deletion. Compound heterozygous GRK1 variants c.55C > T (p.R19*) and c.1412delC (p.P471Lfs*52) were found in patient 2. In patient 3, compound heterozygous GRK1 variants c.946C > A (p.R316S) and c.1388 T > C (p. L463P) were detected. CONCLUSIONS We reported the first two Chinese Oguchi patients with novel GRK1 pathogenic variants (P471Lfs*52, R316S, L463P) and one Oguchi case with SAG, indicating both GRK1 and SAG are important causative genes in Chinese Oguchi patients.
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Affiliation(s)
- Xing Wei
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, No. 1, Shuai Fu Yuan, Beijing, 100730, People's Republic of China
| | - Hui Li
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, No. 1, Shuai Fu Yuan, Beijing, 100730, People's Republic of China
| | - Shijing Wu
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, No. 1, Shuai Fu Yuan, Beijing, 100730, People's Republic of China
| | - Tian Zhu
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, No. 1, Shuai Fu Yuan, Beijing, 100730, People's Republic of China
| | - Ruifang Sui
- Department of Ophthalmology, State Key Laboratory of Complex Severe and Rare Diseases, Chinese Academy of Medical Sciences, Peking Union Medical College Hospital, No. 1, Shuai Fu Yuan, Beijing, 100730, People's Republic of China.
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Akula JD, Ambrosio L, Howard FI, Hansen RM, Fulton AB. Extracting the ON and OFF contributions to the full-field photopic flash electroretinogram using summed growth curves. Exp Eye Res 2019; 189:107827. [PMID: 31600486 DOI: 10.1016/j.exer.2019.107827] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 09/27/2019] [Accepted: 10/02/2019] [Indexed: 10/25/2022]
Abstract
Under cone-mediated (photopic) conditions, an "instantaneous" flash of light, including both stimulus onset and offset, will simultaneously activate both "ON" and "OFF" bipolar cells, which either depolarize (ON) or hyperpolarize (OFF) in response and, respectively, produce positive-going and negative-going deflections in the electroretinogram (ERG). The stimulus-response (SR) relationship of the photopic ON response demonstrates logistic growth, like that manifested in the rod-mediated (scotopic) b-wave, which is driven by a single class of depolarizing bipolar cell. However, the photopic b-wave SR function is importantly shaped by OFF responses, leading to a "photopic hill." Furthermore, both on and off stimuli elicit activity in both ON and OFF bipolar cells. This has made it difficult to produce meaningful parameters for ready interpretation of the photopic b-wave SR relationship. Therefore, we evaluated whether the sum of sigmoidal SR functions, as descriptors of the depolarizing and hyperpolarizing components of the photopic flash ERG, could be used to elucidate and quantitate the mechanisms that produce the photopic hill. We used a novel fitting routine to optimize a sum of simple sigmoidal curves to SR data in five groups of subjects: Healthy adult, 10-week-old infant, congenital stationary night blindness (CSNB), X-linked juvenile retinoschisis (XJR), and preterm-born, both without and with a history of retinopathy of prematurity (ROP). Differences in ON and OFF amplitude, sensitivity, and implicit time among the groups were then compared using parameters extracted from these fits. We found that our modeling procedure enabled plausible derivations of ON and OFF pathway contributions to the ERG, and that the parameters produced appeared to have physiological relevance. In adult subjects, the ON and OFF amplitudes were similar in magnitude with respectively longer and shorter implicit times. Infant, CSNB, and XJR subjects showed significant ON pathway deficits. History of preterm-birth, without or with a diagnosis of ROP, did not much affect cone responses.
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Affiliation(s)
- James D Akula
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Ophthalmology, Harvard Medical School, Boston, MA, United States.
| | - Lucia Ambrosio
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Fiona I Howard
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Psychology, Northeastern University, Boston, MA, United States
| | - Ronald M Hansen
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Ophthalmology, Harvard Medical School, Boston, MA, United States
| | - Anne B Fulton
- Ophthalmology, Boston Children's Hospital, Boston, MA, United States; Ophthalmology, Harvard Medical School, Boston, MA, United States
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Disinhibition of intrinsic photosensitive retinal ganglion cells in patients with X-linked congenital stationary night blindness. Graefes Arch Clin Exp Ophthalmol 2019; 257:1207-1215. [PMID: 30982101 DOI: 10.1007/s00417-019-04319-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2018] [Revised: 02/11/2019] [Accepted: 02/15/2019] [Indexed: 10/27/2022] Open
Abstract
PURPOSE To assess the pupil light response (PLR) to chromatic stimulation in patients with different types of X-linked congenital stationary night blindness (CSNB). METHODS Eight patients with CSNB due to CACNA1F and NYX mutations were exposed to blue and red light stimuli, and PLR was evaluated using infrared video pupillography. Pupil responses were compared between CSNB patients and healthy subjects (n = 34) at baseline, at maximum of constriction, for post-illumination pupil responses (PIPR) and the slope of redilation using Cohen's d. A subgroup comparison was performed descriptively between CACNA1F and NYX associated CSNB patients using the same parameters. RESULTS In CSNB, smaller baseline pupil diameters compared to healthy subjects were measured both before blue and red light stimulation (d = 1.44-1.625). The maximum constriction to blue light stimuli was smaller for the CSNB group compared to healthy subjects (d = 1.251) but not for red light stimuli (d = 0.449). Pupil response latencies were prolonged in CSNB for both light stimuli (d = -1.53 for blue and d = -1.011 for red stimulation). No relevant differences were found between the CSNB group and healthy subjects for PIPR (d = 0.01), but the slope of redilation was smaller for CSNB patients (d = 2.12). Paradoxical pupil constriction at light offset was not seen in our patients. CONCLUSION A reduced redilation and smaller baseline pupil diameters for patients with CSNB indicate a disinhibition of intrinsically photosensitive retinal ganglion cells due to affected post-photoreceptor transduction via bipolar cells and can explain the pupillary behavior in our patient group.
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Johnson MA, Jeffrey BG, Messias AMV, Robson AG. ISCEV extended protocol for the stimulus-response series for the dark-adapted full-field ERG b-wave. Doc Ophthalmol 2019; 138:217-227. [PMID: 30929109 DOI: 10.1007/s10633-019-09687-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2019] [Accepted: 03/13/2019] [Indexed: 11/28/2022]
Abstract
The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum protocol for clinical testing but encourages more extensive testing where appropriate. This ISCEV extended protocol describes an extension of the ISCEV full-field ERG standard, in which methods to record and evaluate the growth of the dark-adapted (DA) ERG b-wave with increasing stimulus energy are described. The flashes span a range that includes the weakest flash required to generate a reliable DA ERG b-wave and that required to generate a maximal b-wave amplitude. The DA ERG b-wave stimulus-response series (also known historically as the "intensity-response" or "luminance-response" series) can more comprehensively characterize generalized rod system function than the ISCEV standard ERG protocol and may be of diagnostic or prognostic value in disorders that cause generalized rod system dysfunction.
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Affiliation(s)
- Mary A Johnson
- Department of Ophthalmology and Visual Sciences, University of Maryland School of Medicine, 10 S. Pine St., MSTF Suite 500-A, Baltimore, MD, 21201, USA.
| | - Brett G Jeffrey
- Ophthalmic Genetics and Visual Function Branch, National Eye Institute, Bethesda, MD, USA
| | - André M V Messias
- Oftalmologia e Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Anthony G Robson
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK.,Institute of Ophthalmology, University College London, London, UK
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McCulloch DL, Kondo M, Hamilton R, Lachapelle P, Messias AMV, Robson AG, Ueno S. ISCEV extended protocol for the stimulus-response series for light-adapted full-field ERG. Doc Ophthalmol 2019; 138:205-215. [PMID: 30929108 DOI: 10.1007/s10633-019-09685-8] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 03/06/2019] [Indexed: 12/21/2022]
Abstract
The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum protocol for clinical testing but encourages additional ERG testing when appropriate. This ISCEV extended protocol describes methods to record and evaluate a light-adapted (LA) ERG stimulus-response series with increasing flash strengths. The LA ERG stimulus-response series (also referred to as the luminance-response or intensity-response series in the published literature) can characterise generalised cone system function more comprehensively than the ISCEV standard LA ERGs alone. The amplitude of LA ERG a-waves, arising from cones and cone off-bipolar cells, typically shows a saturating function. The LA ERG b-wave amplitudes, which arise primarily from activity of retinal bipolar cells, show an amplitude peak followed by a nonzero plateau (the "photopic hill" phenomenon). This ISCEV extended protocol specifies a stimulus-response series suitable to evaluate generalised dysfunction affecting the LA retina, to aid in distinguishing between the on- and off-responses of the cone system and to monitor ERG changes in these characteristics. The LA ERG stimulus-response series for a- and b-waves is recorded to a sequence of nine flash stimuli ranging from 0.03 to 300 cd s m-2, superimposed on a standard background of 30 cd m-2. A shorter protocol is also presented to measure the mid-range of the function (the "photopic hill") using 5 flash stimuli.
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Affiliation(s)
- Daphne L McCulloch
- School of Optometry and Vision Science, University of Waterloo, 200 University Avenue West, Waterloo, ON, N2L 3G1, Canada.
| | - Mineo Kondo
- Mie University Graduate School of Medicine, Mie, Japan
| | - Ruth Hamilton
- Clinical Physics and Bio-engineering, Royal Hospital for Children, NHS Greater Glasgow & Clyde, Glasgow, UK.,College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Pierre Lachapelle
- Department of Ophthalmology and Neurology-Neurosurgery, McGill University, Montreal, QC, Canada
| | - André M V Messias
- Oftalmologia e Otorrinolaringologia e Cirurgia de Cabeça e Pescoço, School of Medicine of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
| | - Anthony G Robson
- Department of Electrophysiology, Moorfields Eye Hospital, London, UK.,Institute of Ophthalmology, University College London, London, UK
| | - Shinji Ueno
- Ophthalmology, Nagoya University Graduate School of Medicine, Nagoya, Japan
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Oh A, Loew ER, Foster ML, Davidson MG, English RV, Gervais KJ, Herring IP, Mowat FM. Phenotypic characterization of complete CSNB in the inbred research beagle: how common is CSNB in research and companion dogs? Doc Ophthalmol 2018; 137:87-101. [PMID: 30051304 DOI: 10.1007/s10633-018-9653-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2018] [Accepted: 07/23/2018] [Indexed: 01/23/2023]
Abstract
PURPOSE Although congenital stationary night blindness (CSNB) has been described in a Japanese beagle dog research colony, certain clinical correlates with human CSNB have not yet been described, nor has an estimate of frequency of the condition been made in inbred and outbred beagle populations. METHODS A beagle with CSNB obtained from a commercial research dog supplier in the USA and matched control dogs (n = 3) underwent examination, refraction, ocular imaging, assessment of visual navigation ability and detailed electroretinography (ERG). Retrospective review of ERGs in two independent groups of inbred (n = 15 and 537, respectively) and one group of outbred dogs (n = 36) was used to estimate CSNB frequency in these populations. RESULTS In the affected dog, there were absent dark-adapted b-waves in response to dim-light flashes, severely reduced dark-adapted b-waves in response to bright-light flashes, and normal light-adapted b-waves with a-waves that had broadened troughs. Long-flash ERGs confirmed a markedly reduced b-wave with a preserved d-wave, consistent with cone ON-bipolar cell dysfunction. There was evidence of normal rod photoreceptor a-wave dark adaptation, and rapid light adaptation. In the wider beagle populations, five inbred beagles had a b/a wave ratio of < 1 in dark-adapted bright-flash ERG, whereas no outbred beagles had ERGs consistent with CSNB. CONCLUSIONS The identified dog had clinical findings consistent with complete type CSNB, similar to that described in the Japanese colony. CSNB appears to be a rare disorder in the wider beagle population, although its detection could confound studies that use retinal function as an outcome measure in research dogs, necessitating careful baseline studies to be performed prior to experimentation.
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Affiliation(s)
- Annie Oh
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA
| | - Ellis R Loew
- Department of Biomedical Sciences, Cornell University College of Veterinary Medicine, Ithaca, NY, 14853, USA
| | - Melanie L Foster
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA
| | - Michael G Davidson
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA
| | | | - Kristen J Gervais
- Department of Veterinary Clinical Sciences, The Ohio State University College of Veterinary Medicine, Columbus, OH, 43210, USA
| | - Ian P Herring
- Department of Small Animal Clinical Sciences, Virginia-Maryland Regional College of Veterinary Medicine, Blacksburg, VA, 24061, USA
| | - Freya M Mowat
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC, 27606, USA.
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Abstract
The International Society for Clinical Electrophysiology of Vision (ISCEV) standard for full-field electroretinography (ERG) describes a minimum procedure, but encourages more extensive testing. This ISCEV extended protocol describes an extension to the ERG standard, namely the photopic On-Off ERG, and outlines common clinical applications. A light stimulus duration of 150-200 ms is used in the presence of a rod-suppressing background to elicit cone-driven On- and Off-system ERG components. The On-response occurs after the stimulus onset and has a negative a-wave and positive b-wave. The Off d-wave is a positive component evoked by stimulus offset. Common diagnoses that may benefit from additional photopic On-Off ERG testing include retinal dystrophies and retinal disorders that cause dysfunction at a level that is post-phototransduction or post-receptoral. On-Off ERGs assess the relative involvement of On- and Off-systems and may be of use in the diagnosis of disorders such as complete and incomplete congenital stationary night blindness (complete and incomplete CSNB), melanoma-associated retinopathy, and some forms of autoimmune retinopathy. The photopic On-Off ERGs may also be useful in X-linked retinoschisis, Batten disease, Duchenne muscular dystrophy, spinocerebellar degeneration, quinine toxicity, and other retinal disorders.
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10
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Deferoxamine-induced electronegative ERG responses. Doc Ophthalmol 2018; 137:15-23. [PMID: 29770904 DOI: 10.1007/s10633-018-9640-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Accepted: 05/09/2018] [Indexed: 01/28/2023]
Abstract
PURPOSE To report a case of deferoxamine-induced retinopathy characterized by electroretinography (ERG), optical coherence tomography angiography (OCT-A), and other multimodal imaging. METHODS This is an observational case report of one patient. Full-field ERG was performed. OCT-A, spectral-domain optical coherence tomography (SD-OCT), color fundus photography, and fundus autofluorescence were used to characterize the retinopathy induced by deferoxamine use. RESULTS A 64-year-old man with a history of β-thalassemia intermedia presented with worsening visual acuity, nyctalopia, and electronegative ERG. OCT-A revealed atrophy of the choriocapillaris in areas of hypoautofluorescence, corresponding to regions of retinal atrophy. SD-OCT showed disruption of the ellipsoid zone, granular hyperreflective deposits within the retinal pigment epithelium, thinning of the retinal layers, and extensive choroidal sclerosis and atrophy of the retinal pigment epithelium. CONCLUSION Deferoxamine-induced retinopathy can manifest with electronegative maximal ERG responses, and OCT-A can be used to detect deferoxamine toxicity.
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Waldner DM, Giraldo Sierra NC, Bonfield S, Nguyen L, Dimopoulos IS, Sauvé Y, Stell WK, Bech-Hansen NT. Cone dystrophy and ectopic synaptogenesis in a Cacna1f loss of function model of congenital stationary night blindness (CSNB2A). Channels (Austin) 2018; 12:17-33. [PMID: 29179637 PMCID: PMC5972796 DOI: 10.1080/19336950.2017.1401688] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 10/22/2017] [Accepted: 10/31/2017] [Indexed: 01/05/2023] Open
Abstract
Congenital stationary night blindness 2A (CSNB2A) is an X-linked retinal disorder, characterized by phenotypically variable signs and symptoms of impaired vision. CSNB2A is due to mutations in CACNA1F, which codes for the pore-forming α1F subunit of a L-type voltage-gated calcium channel, Cav1.4. Mouse models of CSNB2A, used for characterizing the effects of various Cacna1f mutations, have revealed greater severity of defects than in human CSNB2A. Specifically, Cacna1f-knockout mice show an apparent lack of visual function, gradual retinal degeneration, and disruption of photoreceptor synaptic terminals. Several reports have also noted cone-specific disruptions, including axonal abnormalities, dystrophy, and cell death. We have explored further the involvement of cones in our 'G305X' mouse model of CSNB2A, which has a premature truncation, loss-of-function mutation in Cacna1f. We show that the expression of genes for several phototransduction-related cone markers is down-regulated, while that of several cellular stress- and damage-related markers is up-regulated; and that cone photoreceptor structure and photopic visual function - measured by immunohistochemistry, optokinetic response and electroretinography - deteriorate progressively with age. We also find that dystrophic cone axons establish synapse-like contacts with rod bipolar cell dendrites, which they normally do not contact in wild-type retinas - ectopically, among rod cell bodies in the outer nuclear layer. These data support a role for Cav1.4 in cone synaptic development, cell viability, and synaptic transmission of cone-dependent visual signals. Although our novel finding of cone-to-rod-bipolar cell contacts in this mouse model of a retinal channelopathy may challenge current views of the role of Cav1.4 in photopic vision, it also suggests a potential new target for restorative therapy.
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Affiliation(s)
- D. M. Waldner
- Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - N. C. Giraldo Sierra
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - S. Bonfield
- Department of Neuroscience, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - L. Nguyen
- Department of Medical Genetics, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - I. S. Dimopoulos
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Y. Sauvé
- Department of Ophthalmology and Visual Sciences, University of Alberta, Edmonton, Alberta, Canada
- Department of Physiology, University of Alberta, Edmonton, Alberta, Canada
| | - W. K. Stell
- Department of Cell Biology and Anatomy and Department of Surgery, Hotchkiss Brain Institute, and Alberta Children's Hospital Research Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
| | - N. T. Bech-Hansen
- Department of Medical Genetics, and Department of Surgery, Alberta Children's Hospital Research Institute, and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada
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Men CJ, Bujakowska KM, Comander J, Place E, Bedoukian EC, Zhu X, Leroy BP, Fulton AB, Pierce EA. The importance of genetic testing as demonstrated by two cases of CACNA1F-associated retinal generation misdiagnosed as LCA. Mol Vis 2017; 23:695-706. [PMID: 29062221 PMCID: PMC5640518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2017] [Accepted: 10/08/2017] [Indexed: 11/23/2022] Open
Abstract
PURPOSE To describe in detail cases with an initial diagnosis of Leber congenital amaurosis that were later found to have a hemizygous mutation in the CACNA1F gene. METHODS The patients underwent a detailed ophthalmological evaluation and full-field electroretinography (ERG). Selective targeted capture and whole-exome next-generation sequencing (NGS) were used to find the disease-causing mutations. RESULTS Patient 1 presented at age 3 months with nystagmus, normal visual attention, and a normal fundus exam. ERG responses were severely decreased. Patient 2 presented with nystagmus, severe hyperopia, esotropia, and visual acuity of 20/360 oculus dexter (OD) and 20/270 oculus sinister (OS) at age 5 months. His fundus exam showed slightly increased pigmentation around the foveae. The scotopic ERG responses were severely decreased and photopic responses mildly decreased. Based on the initial presentation, both patients received the clinical diagnosis of Leber congenital amaurosis (LCA). However, genetic testing showed no mutations in known LCA genes. Instead, broader genetic testing using NGS showed point mutations in the CACNA1F gene, which is reported to be associated with type 2 congenital stationary night blindness (CSNB2). CONCLUSIONS These two cases demonstrate the clinical overlap between LCA and CSNB in infants and young children. Genetic testing is an essential tool in these cases and provides a more accurate diagnosis and prognosis for patients with inherited retinal degenerative disorders.
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Affiliation(s)
- Clara J. Men
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA
| | - Kinga M. Bujakowska
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA
| | - Jason Comander
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA
| | - Emily Place
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA
| | - Emma C. Bedoukian
- Ophthalmic Genetics & Visual Electrophysiology, Division of Ophthalmology, The Children’s Hospital of Philadelphia, PA
| | - Xiaosong Zhu
- Ophthalmic Genetics & Visual Electrophysiology, Division of Ophthalmology, The Children’s Hospital of Philadelphia, PA
| | - Bart P. Leroy
- Ophthalmic Genetics & Visual Electrophysiology, Division of Ophthalmology, The Children’s Hospital of Philadelphia, PA,Department of Ophthalmology & Center for Medical Genetics, Ghent University Hospital & Ghent University, Ghent, Belgium
| | - Anne B. Fulton
- Department of Ophthalmology, Boston Children’s Hospital, Boston, MA
| | - Eric A. Pierce
- Ocular Genomics Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA
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Wang L, el Azazi M, Eklund A, Burstedt M, Wachtmeister L. The response of the neuronal adaptive system to background illumination and readaptation to dark in the immature retina. Acta Ophthalmol 2015; 93:146-53. [PMID: 24924739 DOI: 10.1111/aos.12456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 05/01/2014] [Indexed: 11/28/2022]
Abstract
PURPOSE Developmental characteristics of the neuronal adaptive system of the retina, focusing on background light (BGL) adaptation and readaptation functions, were studied by measuring the oscillatory response (SOP) of the electroretinogram (ERG). METHODS Digitally filtered and conventional ERGs were simultaneously recorded. Rats aged 15 and 17 days were studied during exposure to BGLs of two mesopic intensities and during readaptation to dark. RESULTS Results were compared to adult rats. In 'low mesopic' BGL SOP instantly dropped significantly to about half of its dark-adapted (DA) value contrary to mature rats, in which the SOP significantly increased. In 'high mesopic' BGL SOP decreased to about 20% and 30% of DA values in immature and adult rats, respectively. The process of recovery of SOP in darkness lacked the transient enhancement immediately as BGL was turned off, characteristic of adult rats. There were no major age differences in adaptive behaviour of a-wave. In young rats, recovery of b-wave was relatively slower. CONCLUSIONS Properties of BGL adaptation and readaptation functions of the neuronal adaptive system in baby retina differed compared to the adult one by being less forceful and more restrained. Handling of mesopic illumination and recovery in the dark was immature. Development of these functions of the neuronal adaptive system progresses postnatally and lags behind that of the photoreceptor response and seems to be delayed also compared to that of the bipolar response.
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Affiliation(s)
- Ling Wang
- Department of Ophthalmology; Ruijin Hospital; Medicine School of Shanghai; Jiaotong University; Shanghai China
- Department of Clinical Sciences, Ophthalmology; Umeå University; Umeå Sweden
| | - Mildred el Azazi
- Department of Clinical Neuroscience, Ophthalmology and Vision; Karolinska Institutet; Stockholm Sweden
| | - Anders Eklund
- Department of Radiation Sciences; Umeå University; Umeå Sweden
| | - Marie Burstedt
- Department of Clinical Sciences, Ophthalmology; Umeå University; Umeå Sweden
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Electroretinographic characteristics in children with infantile nystagmus syndrome and early-onset retinal dystrophies. Eur J Ophthalmol 2014; 25:33-42. [PMID: 25096283 DOI: 10.5301/ejo.5000493] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/06/2014] [Indexed: 11/20/2022]
Abstract
PURPOSE To differentiate early-onset retinal dystrophies on the basis of electroretinogram (ERG) characteristics in children with infantile nystagmus syndrome (INS). METHODS Thirty-seven children with INS and early-onset retinal dystrophies were included, with diagnosis according to clinical and ERG findings. Three ERG protocols were used according to the child's age and 17 children were followed with 2 protocols: 27 (mean 2.1 years) were recorded with skin electrodes to flash stimulation, 16 (mean 6.5 years) with skin electrodes to full-field stimulation, and 11 (mean 12.2 years) with HK electrodes to full-field stimulation. The ERGs were compared to those of age-matched controls, with differences significant if p<0.05. RESULTS Clinical and electrophysiologic findings were in agreement across all of the children. In nine children with Leber congenital amaurosis, the scotopic and photopic ERGs were not recordable under all protocols. Six children with congenital stationary night blindness (CSNB) had electronegative scotopic ERG under all protocols, those with complete CSNB had absent rod ERG, and those with incomplete CSNB had reduced rod ERG. Eight children with achromatopsia had nonrecordable photopic and subnormal scotopic ERG under all protocols. The implicit times of the scotopic b-waves were prolonged. One child had blue-cone monochromatism and reduced photopic and normal S-cone ERG. Six children with cone-rod dystrophy without systemic disorder, and seven children with systemic disorder, had affected photopic and scotopic ERGs under all protocols. CONCLUSIONS In children with INS, some early-onset retinal dystrophies can be differentiated through ERGs, also with skin electrodes.
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