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Find video protocols related to scientific articles indexed in Pubmed.
Multimodal imaging in a case of deferoxamine-induced maculopathy.
Retin Cases Brief Rep
PUBLISHED: 11-06-2014
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To report a case of deferoxamine-induced maculopathy and present the use of multimodal retinal imaging to study this disease entity.
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Correlations Amongst Near-Infrared and Short-Wavelength Autofluorescence and Spectral Domain Optical Coherence Tomography in Recessive Stargardt Disease.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 10-25-2014
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Purpose: Short-wavelength (SW) fundus autofluorescence (AF) is considered to originate from lipofuscin in retinal pigment epithelium (RPE) and near-infrared (NIR) AF from melanin. In patients with recessive Stargardt disease (STGD1), we correlated SW-AF and NIR-AF with structural information obtained by spectral domain optical coherence tomography (SD-OCT). Methods: Twenty-four STGD1 patients (45 eyes; age 8 to 61 years) carrying confirmed disease-associated ABCA4 mutations were studied prospectively. SW-AF, NIR-AF and SD-OCT images were acquired. Results: Five phenotypes were identified according to features of the central lesion and extent of fundus change. Central zones of reduced NIR-AF were typically larger than areas of diminished SW-AF and reduced NIR-AF usually approximated areas of ellipsoid zone (EZ) loss identified by SD-OCT (group 1; r, 0.93, p<0.0001). In patients having a central lesion with overlapping parafoveal rings of increased NIR-AF and SW-AF (group 3), the extent of EZ loss was strongly correlated with the inner diameter of the NIR-AF ring (r, 0.89, p<0.0001) and the eccentricity of the outer border of the NIR-AF ring was greater than that of the SW-AF ring. Conclusions: Lesion areas were more completely delineated in NIR-AF images than with SW-AF. In most cases EZ loss was observed only at locations where NIR-AF was reduced or absent, indicating that RPE cell atrophy occurs in advance of photoreceptor cell degeneration. Since SW-AF was often increased within the central area of EZ disruption, degenerating photoreceptor cells may produce lipofuscin at accelerated levels. Consideration is given to mechanisms underlying hyper-NIR-AF in conjunction with increased SW-AF.
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Structural and Genetic Assessment of the ABCA4-Associated Optical Gap Phenotype.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 10-11-2014
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To investigate the developmental stages and genetic etiology of the optical gap phenotype in recessive Stargardt disease (STGD1).
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Spinster homolog 2 (spns2) deficiency causes early onset progressive hearing loss.
PLoS Genet.
PUBLISHED: 10-01-2014
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Spinster homolog 2 (Spns2) acts as a Sphingosine-1-phosphate (S1P) transporter in zebrafish and mice, regulating heart development and lymphocyte trafficking respectively. S1P is a biologically active lysophospholipid with multiple roles in signalling. The mechanism of action of Spns2 is still elusive in mammals. Here, we report that Spns2-deficient mice rapidly lost auditory sensitivity and endocochlear potential (EP) from 2 to 3 weeks old. We found progressive degeneration of sensory hair cells in the organ of Corti, but the earliest defect was a decline in the EP, suggesting that dysfunction of the lateral wall was the primary lesion. In the lateral wall of adult mutants, we observed structural changes of marginal cell boundaries and of strial capillaries, and reduced expression of several key proteins involved in the generation of the EP (Kcnj10, Kcnq1, Gjb2 and Gjb6), but these changes were likely to be secondary. Permeability of the boundaries of the stria vascularis and of the strial capillaries appeared normal. We also found focal retinal degeneration and anomalies of retinal capillaries together with anterior eye defects in Spns2 mutant mice. Targeted inactivation of Spns2 in red blood cells, platelets, or lymphatic or vascular endothelial cells did not affect hearing, but targeted ablation of Spns2 in the cochlea using a Sox10-Cre allele produced a similar auditory phenotype to the original mutation, suggesting that local Spns2 expression is critical for hearing in mammals. These findings indicate that Spns2 is required for normal maintenance of the EP and hence for normal auditory function, and support a role for S1P signalling in hearing.
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The external limiting membrane in early-onset Stargardt disease.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 08-19-2014
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To describe pathologic changes of the external limiting membrane (ELM) in young patients with early-onset Stargardt (STGD1) disease.
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Analysis of the ABCA4 genomic locus in Stargardt disease.
Hum. Mol. Genet.
PUBLISHED: 07-31-2014
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Autosomal recessive Stargardt disease (STGD1, MIM 248200) is caused by mutations in the ABCA4 gene. Complete sequencing of ABCA4 in STGD patients identifies compound heterozygous or homozygous disease-associated alleles in 65-70% of patients and only one mutation in 15-20% of patients. This study was designed to find the missing disease-causing ABCA4 variation by a combination of next-generation sequencing (NGS), array-Comparative Genome Hybridization (aCGH) screening, familial segregation and in silico analyses. The entire 140 kb ABCA4 genomic locus was sequenced in 114 STGD patients with one known ABCA4 exonic mutation revealing, on average, 200 intronic variants per sample. Filtering of these data resulted in 141 candidates for new mutations. Two variants were detected in four samples, two in three samples, and 20 variants in two samples, the remaining 117 new variants were detected only once. Multimodal analysis suggested 12 new likely pathogenic intronic ABCA4 variants, some of which were specific to (isolated) ethnic groups. No copy number variation (large deletions and insertions) was detected in any patient suggesting that it is a very rare event in the ABCA4 locus. Many variants were excluded since they were not conserved in non-human primates, were frequent in African populations and, therefore, represented ancestral, and not disease-associated, variants. The sequence variability in the ABCA4 locus is extensive and the non-coding sequences do not harbor frequent mutations in STGD patients of European-American descent. Defining disease-associated alleles in the ABCA4 locus requires exceptionally well characterized large cohorts and extensive analyses by a combination of various approaches.
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Choroidal and retinal thickening in severe preeclampsia.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 07-31-2014
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To compare choroidal thickness and retinal macular volume (RMV) among three groups of women: severe preeclampsia postpartum, normotensive postpartum, and normotensive nongravid. While visual disturbances often accompany severe preeclampsia, the underlying choroidal and retinal changes responsible for these symptoms have not been described.
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Early Structural Anomalies Observed by High-Resolution Imaging in Two Related Cases of Autosomal-Dominant Retinitis Pigmentosa.
Ophthalmic Surg Lasers Imaging Retina
PUBLISHED: 06-27-2014
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The authors report the use of adaptive-optics scanning laser ophthalmoscopy (AO-SLO) to investigate RHO, D190N autosomal-dominant retinitis pigmentosa in two siblings (11 and 16 years old, respectively). Each patient exhibited distinct hyperautofluorescence patterns in which the outer borders corresponded to inner segment ellipsoid band disruption. Areas within the hyperautofluorescence patterns exhibited normal photoreceptor outer segments and retinal pigment epithelium. However, AO-SLO imaging revealed noticeable spacing irregularities in the cone mosaic. AO-SLO allows researchers to characterize retinal structural abnormalities with precision so that early structural changes in retinitis pigmentosa can be identified and reconciled with genetic findings. [Ophthalmic Surg Lasers Imaging Retina. 2014;45:xxx-xxx.].
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New syndrome with retinitis pigmentosa is caused by nonsense mutations in retinol dehydrogenase RDH11.
Hum. Mol. Genet.
PUBLISHED: 06-10-2014
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Retinitis pigmentosa (RP), a genetically heterogeneous group of retinopathies that occur in both non-syndromic and syndromic forms, is caused by mutations in ?100 genes. Although recent advances in next-generation sequencing have aided in the discovery of novel RP genes, a number of the underlying contributing genes and loci remain to be identified. We investigated three siblings, born to asymptomatic parents of Italian-American descent, who each presented with atypical RP with systemic features, including facial dysmorphologies, psychomotor developmental delays recognized since early childhood, learning disabilities and short stature. RP-associated ophthalmological findings included salt-and-pepper retinopathy, attenuation of the arterioles and generalized rod-cone dysfunction as determined by almost extinguished electroretinogram in 2 of 3 siblings. Atypical for RP features included mottled macula at an early age and peripapillary sparing of the retinal pigment epithelium. Whole-exome sequencing data, queried under a recessive model of inheritance, identified compound heterozygous stop mutations, c.C199T:p.R67* and c.C322T:p.R108*, in the retinol dehydrogenase 11 (RDH11) gene, resulting in a non-functional protein, in all affected children. In summary, deleterious mutations in RDH11, an important enzyme for vision-related and systemic retinoic acid metabolism, cause a new syndrome with RP.
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Gene therapy in patient-specific stem cell lines and a preclinical model of retinitis pigmentosa with membrane frizzled-related protein defects.
Mol. Ther.
PUBLISHED: 05-23-2014
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Defects in Membrane Frizzled-related Protein (MFRP) cause autosomal recessive retinitis pigmentosa (RP). MFRP codes for a retinal pigment epithelium (RPE)-specific membrane receptor of unknown function. In patient-specific induced pluripotent stem (iPS)-derived RPE cells, precise levels of MFRP, and its dicistronic partner CTRP5, are critical to the regulation of actin organization. Overexpression of CTRP5 in naïve human RPE cells phenocopied behavior of MFRP-deficient patient RPE (iPS-RPE) cells. AAV8 (Y733F) vector expressing human MFRP rescued the actin disorganization phenotype and restored apical microvilli in patient-specific iPS-RPE cell lines. As a result, AAV-treated MFRP mutant iPS-RPE recovered pigmentation and transepithelial resistance. The efficacy of AAV-mediated gene therapy was also evaluated in Mfrp(rd6)/Mfrp(rd6) mice--an established preclinical model of RP--and long-term improvement in visual function was observed in AAV-Mfrp-treated mice. This report is the first to indicate the successful use of human iPS-RPE cells as a recipient for gene therapy. The observed favorable response to gene therapy in both patient-specific cell lines, and the Mfrp(rd6)/Mfrp(rd6) preclinical model suggests that this form of degeneration caused by MFRP mutations is a potential target for interventional trials.
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Quantitative Fundus Autofluorescence Distinguishes ABCA4-Associated and Non-ABCA4-Associated Bull's-Eye Maculopathy.
Ophthalmology
PUBLISHED: 05-14-2014
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Quantitative fundus autofluorescence (qAF) and spectral-domain optical coherence tomography (SD OCT) were performed in patients with bull's-eye maculopathy (BEM) to identify phenotypic markers that can aid in the differentiation of ABCA4-associated and non-ABCA4-associated disease.
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Next-generation sequencing revealed a novel mutation in the gene encoding the beta subunit of rod phosphodiesterase.
Ophthalmic Genet.
PUBLISHED: 05-14-2014
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To report the phenotypes caused by a novel mutation in the PDE6B gene in a family with two affected siblings and one affected cousin with a 2-year follow-up.
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Genetic and clinical analysis of ABCA4-associated disease in African American patients.
Hum. Mutat.
PUBLISHED: 05-02-2014
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Autosomal recessive Stargardt disease (STGD1) is caused by hundreds of mutations in the ABCA4 gene, which are often specific to racial and ethnic groups. Here, we investigated the ABCA4 variation and their phenotypic expression in a cohort of 44 patients of African American descent, a previously under-characterized racial group. Patients were screened for mutations in ABCA4 by next-generation sequencing and array-comparative genomic hybridization (aCGH), followed by analyses for pathogenicity by in silico programs. Thorough ophthalmic examination was performed on all patients. At least two (expected) disease-causing alleles in the ABCA4 gene were identified in 27 (61.4%) patients, one allele in 11 (25%) patients, and no ABCA4 mutations were found in six (13.6%) patients. Altogether, 39 different disease-causing ABCA4 variants, including seven new, were identified on 65 (74%) chromosomes, most of which were unique for this racial group. The most frequent ABCA4 mutation in this cohort was c.6320G>A (p.(R2107H)), representing 19.3% of all disease-associated alleles. No large copy number variants were identified in any patient. Most patients reported later onset of symptoms. In summary, the ABCA4 mutation spectrum in patients of West African descent differs significantly from that in patients of European descent, resulting in a later onset and "milder" disease.
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Juvenile-onset macular degeneration and allied disorders.
Dev Ophthalmol
PUBLISHED: 04-10-2014
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While age-related macular degeneration (AMD) is a leading cause of central vision loss among the elderly, many inherited diseases that present earlier in life share features of AMD. These diseases of juvenile-onset macular degeneration include Stargardt disease, Best disease, retinitis pigmentosa, X-linked retinoschisis, and other allied disorders. In particular, they can be accompanied by the appearance of drusen, geographic atrophy, macular hyperpigmentation, choroidal neovascularization, and disciform scarring just as in AMD, and often may be confused for the adult form of the disease. Diagnosis based on funduscopic findings alone can be challenging. However, the use of diagnostic studies such as electroretinography, electrooculography, optical coherence tomography, and fundus autofluorescence in conjunction with genetic testing can lead to an accurate diagnosis.
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General pathophysiology in retinal degeneration.
Dev Ophthalmol
PUBLISHED: 04-10-2014
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Retinal degeneration, including that seen in age-related macular degeneration and retinitis pigmentosa (RP), is the most common form of neural degenerative disease in the world. There is great genetic and allelic heterogeneity of the various retinal dystrophies. Classifications of these diseases can be ambiguous, as there are similar clinical presentations in retinal degenerations arising from different genetic mechanisms. As would be expected, alterations in the activity of the phototransduction cascade, such as changes affecting the renewal and shedding of the photoreceptor OS, visual transduction, and/or retinol metabolism have a great impact on the health of the retina. Mutations within any of the molecules responsible for these visual processes cause several types of retinal and retinal pigment epithelium degenerative diseases. Apoptosis has been implicated in the rod cell loss seen in a mouse model of RP, but the precise mechanisms that connect the activation of these pathways to the loss of phosphodiesterase (PDE6?) function has yet to be defined. Additionally, the activation of apoptosis by CCAAT/-enhancer-binding protein homologous protein (CHOP), after activation of the unfolded protein response pathway, may be responsible for cell death, although the mechanism remains unknown. However, the mechanisms of cell death after loss of function of PDE6, which is a commonly studied mammalian model in research, may be generalizable to loss of function of different key proteins involved in the phototransduction cascade.
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Quantitative fundus autofluorescence in recessive Stargardt disease.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 03-29-2014
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To quantify fundus autofluorescence (qAF) in patients with recessive Stargardt disease (STGD1).
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Whole exome sequencing identifies CRB1 defect in an unusual maculopathy phenotype.
Ophthalmology
PUBLISHED: 03-07-2014
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To report a new phenotype caused by mutations in the CRB1 gene in a family with 2 affected siblings.
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Quantitative fundus autofluorescence and optical coherence tomography in best vitelliform macular dystrophy.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 02-15-2014
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Quantitative fundus autofluorescence (qAF), spectral domain optical coherence tomography (SD-OCT) segmentation, and multimodal imaging were performed to elucidate the pathogenesis of Best vitelliform macular dystrophy (BVMD) and to identify abnormalities in lesion versus nonlesion fundus areas.
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Spectral-domain optical coherence tomography staging and autofluorescence imaging in achromatopsia.
JAMA Ophthalmol
PUBLISHED: 02-08-2014
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IMPORTANCE Evidence is mounting that achromatopsia is a progressive retinal degeneration, and treatments for this condition are on the horizon. OBJECTIVES To categorize achromatopsia into clinically identifiable stages using spectral-domain optical coherence tomography and to describe fundus autofluorescence imaging in this condition. DESIGN, SETTING, AND PARTICIPANTS A prospective observational study was performed between 2010 and 2012 at the Edward S. Harkness Eye Institute, New York-Presbyterian Hospital. Participants included 17 patients (aged 10-62 years) with full-field electroretinography-confirmed achromatopsia. MAIN OUTCOMES AND MEASURES Spectral-domain optical coherence tomography features and staging system, fundus autofluorescence and near-infrared reflectance features and their correlation to optical coherence tomography, and genetic mutations served as the outcomes and measures. RESULTS Achromatopsia was categorized into 5 stages on spectral-domain optical coherence tomography: stage 1 (2 patients [12%]), intact outer retina; stage 2 (2 patients [12%]), inner segment ellipsoid line disruption; stage 3 (5 patients [29%]), presence of an optically empty space; stage 4 (5 patients [29%]), optically empty space with partial retinal pigment epithelium disruption; and stage 5 (3 patients [18%]), complete retinal pigment epithelium disruption and/or loss of the outer nuclear layer. Stage 1 patients showed isolated hyperreflectivity of the external limiting membrane in the fovea, and the external limiting membrane was hyperreflective above each optically empty space. On near infrared reflectance imaging, the fovea was normal, hyporeflective, or showed both hyporeflective and hyperreflective features. All patients demonstrated autofluorescence abnormalities in the fovea and/or parafovea: 9 participants (53%) had reduced or absent autofluorescence surrounded by increased autofluorescence, 4 individuals (24%) showed only reduced or absent autofluorescence, 3 patients (18%) displayed only increased autofluorescence, and 1 individual (6%) exhibited decreased macular pigment contrast. Inner segment ellipsoid line loss generally correlated with the area of reduced autofluorescence, but hyperautofluorescence extended into this region in 2 patients (12%). Bilateral coloboma-like atrophic macular lesions were observed in 1 patient (6%). Five novel mutations were identified (4 in the CNGA3 gene and 1 in the CNGB3 gene). CONCLUSIONS AND RELEVANCE Achromatopsia often demonstrates hyperautofluorescence suggestive of progressive retinal degeneration. The proposed staging system facilitates classification of the disease into different phases of progression and may have therapeutic implications.
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A drosophila genetic resource of mutants to study mechanisms underlying human genetic diseases.
Cell
PUBLISHED: 02-07-2014
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Invertebrate model systems are powerful tools for studying human disease owing to their genetic tractability and ease of screening. We conducted a mosaic genetic screen of lethal mutations on the Drosophila X chromosome to identify genes required for the development, function, and maintenance of the nervous system. We identified 165 genes, most of whose function has not been studied in vivo. In parallel, we investigated rare variant alleles in 1,929 human exomes from families with unsolved Mendelian disease. Genes that are essential in flies and have multiple human homologs were found to be likely to be associated with human diseases. Merging the human data sets with the fly genes allowed us to identify disease-associated mutations in six families and to provide insights into microcephaly associated with brain dysgenesis. This bidirectional synergism between fly genetics and human genomics facilitates the functional annotation of evolutionarily conserved genes involved in human health.
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Validation of genome-wide association study (GWAS)-identified disease risk alleles with patient-specific stem cell lines.
Hum. Mol. Genet.
PUBLISHED: 02-04-2014
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While the past decade has seen great progress in mapping loci for common diseases, studying how these risk alleles lead to pathology remains a challenge. Age-related macular degeneration (AMD) affects 9 million older Americans, and is characterized by the loss of the retinal pigment epithelium (RPE). Although the closely linked genome-wide association studies ARMS2/HTRA1 genes, located at the chromosome 10q26 locus, are strongly associated with the risk of AMD, their downstream targets are unknown. Low population frequencies of risk alleles in tissue banks make it impractical to study their function in cells derived from autopsied tissue. Moreover, autopsy eyes from end-stage AMD patients, where age-related RPE atrophy and fibrosis are already present, cannot be used to determine how abnormal ARMS2/HTRA1 expression can initiate RPE pathology. Instead, induced pluripotent stem (iPS) cell-derived RPE from patients provides us with earlier stage AMD patient-specific cells and allows us to analyze the underlying mechanisms at this critical time point. An unbiased proteome screen of A2E-aged patient-specific iPS-derived RPE cell lines identified superoxide dismutase 2 (SOD2)-mediated antioxidative defense in the genetic allele's susceptibility of AMD. The AMD-associated risk haplotype (T-in/del-A) impairs the ability of the RPE to defend against aging-related oxidative stress. SOD2 defense is impaired in RPE homozygous for the risk haplotype (T-in/del-A; T-in/del-A), while the effect was less pronounced in RPE homozygous for the protective haplotype (G-Wt-G; G-Wt-G). ARMS2/HTRA1 risk alleles decrease SOD2 defense, making RPE more susceptible to oxidative damage and thereby contributing to AMD pathogenesis.
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Retinal damage in chloroquine maculopathy, revealed by high resolution imaging: a case report utilizing adaptive optics scanning laser ophthalmoscopy.
Korean J Ophthalmol
PUBLISHED: 01-21-2014
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A 53-year-old Asian woman was treated with hydroxychloroquine and chloroquine for lupus erythematosus. Within a few years, she noticed circle-shaped shadows in her central vision. Upon examination, the patient's visual acuity was 20 / 25 in both eyes. Humphrey visual field (HVF) testing revealed a central visual defect, and fundoscopy showed a ring-shaped area of parafoveal retinal pigment epithelium depigmentation. Fundus autofluorescence imaging showed a hypofluorescent lesion consistent with bull's eye retinopathy. Adaptive optics scanning laser ophthalmoscope (AO-SLO) revealed patch cone mosaic lesions, in which cones were missing or lost. In addition, the remaining cones consisted of asymmetrical shapes and sizes that varied in brightness. Unlike previous studies employing deformable mirrors for wavefront aberration correction, our AO-SLO approach utilized dual liquid crystal on silicon spatial light modulators. Thus, by using AO-SLO, we were able to create a photographic montage consisting of high quality images. Disrupted cone AO-SLO images were matched with visual field test results and functional deficits were associated with a precise location on the montage, which allowed correlation of histological findings with functional changes determined by HVF. We also investigated whether adaptive optics imaging was more sensitive to anatomical changes compared with spectral-domain optical coherence tomography.
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Generation of induced pluripotent stem cells from conjunctiva.
Graefes Arch. Clin. Exp. Ophthalmol.
PUBLISHED: 01-14-2014
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The objective of this study was to determine whether cells from the conjunctiva could be reprogrammed into induced pluripotent stem (iPS) cells, providing an alternative source of stem cells.
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Cone photoreceptor abnormalities correlate with vision loss in a case of acute posterior multifocal placoid pigment epitheliopathy.
Ophthalmic Surg Lasers Imaging Retina
PUBLISHED: 01-08-2014
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The authors report adaptive optics scanning laser ophthalmoscopy (AO-SLO) findings in a case of acute posterior multifocal placoid pigment epitheliopathy. The right eye showed an island of coarse, hyperreflective speckles surrounded by a dark annulus lacking cone cells, which were associated with reduced MP1 sensitivity and abnormal findings in other imaging modalities. Although dark lesions were also detected in the left eye, the correlated spectral-domain optical coherence tomography images were normal. AO-SLO allowed for the direct observation of retinal disruptions and the ability of this technology to detect abnormalities in the left eye demonstrates a superior ability for in-depth retinal imaging.
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Functional validation of a human CAPN5 exome variant by lentiviral transduction into mouse retina.
Hum. Mol. Genet.
PUBLISHED: 12-30-2013
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Exome sequencing indicated that the gene encoding the calpain-5 protease, CAPN5, is the likely cause of retinal degeneration and autoimmune uveitis in human patients with autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV, OMIM #193235). To explore the mechanism of ADNIV, a human CAPN5 disease allele was expressed in mouse retinas with a lentiviral vector created to express either the wild-type human (h) CAPN5 or the ADNIV mutant hCAPN5-R243 L allele under a rhodopsin promoter with tandem green fluorescent protein (GFP) expression. Vectors were injected into the subretinal space of perinatal mice. Mouse phenotypes were analyzed using electroretinography, histology, and inflammatory gene expression profiling. Mouse calpain-5 showed high homology to its human ortholog with over 98% sequence identity that includes the ADNIV mutant residue. Calpain-5 protein was expressed in the inner and outer segments of the photoreceptors and in the outer plexiform layer. Expression of the hCAPN5-R243 L allele caused loss of the electroretinogram b-wave, photoreceptor degeneration, and induction of immune cell infiltration and inflammatory genes in the retina, recapitulating major features of the ADNIV phenotype. Intraocular neovascularization and fibrosis was not observed during the study period. Our study shows that expression of the hCAPN5-R243 L disease allele elicits an ADNIV-like disease in mice. It further suggests that ADNIV is due to CAPN5 gain-of-function rather than haploinsufficiency, and retinal expression may be sufficient to generate an autoimmune response. Genetic models of ADNIV in the mouse can be used to explore protease mechanisms in retinal degeneration and inflammation as well as therapeutic testing in pre-clinical models.
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Bilateral Concordance of the Fundus Hyperautofluorescent Ring in Typical Retinitis Pigmentosa Patients.
Ophthalmic Genet.
PUBLISHED: 10-12-2013
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Abstract Background: It has long been assumed that in retinitis pigmentosa, disease presentation and progression are symmetrical. This study investigated whether hyperautofluorescent ring size, one known marker of disease progression, is symmetrical in typical RP patients. Materials and Methods: A total of 88 patients with typical retinitis pigmentosa were enrolled in the study. Each presented with a hyperautofluorescent ring when imaged at baseline with fundus autofluorescence (AF). Vertical and horizontal diameters were analyzed according to mode of inheritance and age group. Seven of 88 patients had data missing in one eye and were excluded from further analysis. Results: There was no significant relationship between hyperautofluorescent ring diameter and inheritance mode. There was a tendency toward smaller ring size with age and 3.7% of subjects displayed marked asymmetry in ring size between right and left eyes, although their electroretinogram results did not differ. Overall, when patients were considered as a group, there was a high correlation between right and left eyes horizontal and vertical diameters (r?=?0.99, p?
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Reticular pseudodrusen in early age-related macular degeneration are associated with choroidal thinning.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 09-28-2013
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To compare choroidal thickness (CT) measurements in early AMD between patients with and without reticular pseudodrusen (RPD) using spectral-domain optical coherence tomography (SD-OCT).
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Distinct characteristics of inferonasal fundus autofluorescence patterns in stargardt disease and retinitis pigmentosa.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 09-28-2013
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To report distinct characteristics of fundus autofluorescence (AF) patterns inferior to the optic disc in recessive Stargardt disease (STGD1) and retinitis pigmentosa (RP).
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Mid-stage intervention achieves similar efficacy as conventional early-stage treatment using gene therapy in a pre-clinical model of retinitis pigmentosa.
Hum. Mol. Genet.
PUBLISHED: 09-18-2013
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Deficiencies in rod-specific cyclic guanosine monophosphate (cGMP) phosphodiesterase-6 (PDE6) are the third most common cause of autosomal recessive retinitis pigmentosa (RP). Previously, viral gene therapy approaches on pre-clinical models with mutations in PDE6 have demonstrated that the photoreceptor cell survival and visual function can be rescued when the gene therapy virus is delivered into the subretinal space before the onset of disease. However, no studies have currently been published that analyze rescue effects after disease onset, a time when human RP patients are diagnosed by a clinician and would receive the treatment. We utilized the AAV2/8(Y733F)-Rho-Pde6? gene therapy virus and injected it into a pre-clinical model of RP with a mutation within the alpha subunit of PDE6: Pde6?(D670G). These mice were previously shown to have long-term photoreceptor cell rescue when this gene therapy virus was delivered before the onset of disease. Now, we have determined that subretinal transduction of this rod-specific transgene at post-natal day (P) 21, when approximately half of the photoreceptor cells have undergone degeneration, is more efficient in rescuing cone than rod photoreceptor function long term. Therefore, AAV2/8(Y733F)-Rho-Pde6? is an effective gene therapy treatment that can be utilized in the clinical setting, in human patients who have lost portions of their peripheral visual field and are in the mid-stage of disease when they first present to an eye-care professional.
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Expanded clinical spectrum of enhanced S-cone syndrome.
JAMA Ophthalmol
PUBLISHED: 08-31-2013
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New funduscopic findings in patients with enhanced S-cone syndrome (ESCS) may help clinicians in diagnosing this rare autosomal recessive retinal dystrophy.
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Therapeutic margins in a novel preclinical model of retinitis pigmentosa.
J. Neurosci.
PUBLISHED: 08-16-2013
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The third-most common cause of autosomal recessive retinitis pigmentosa (RP) is due to defective cGMP phosphodiesterase-6 (PDE6). Previous work using viral gene therapy on PDE6-mutant mouse models demonstrated photoreceptors can be rescued if administered before degeneration. However, whether visual function can be rescued after degeneration onset has not been addressed. This is a clinically important question, as newly diagnosed patients exhibit considerable loss of rods and cones in their peripheral retinas. We have generated and characterized a tamoxifen inducible Cre-loxP rescue allele, Pde6b(Stop), which allows us to temporally correct PDE6-deficiency. Whereas untreated mutants exhibit degeneration, activation of Cre-loxP recombination in early embryogenesis produced stable long-term rescue. Reversal at later time-points showed partial long-term or short-lived rescue. Our results suggest stable restoration of retinal function by gene therapy can be achieved if a sufficient number of rods are treated. Because patients are generally diagnosed after extensive loss of rods, the success of clinical trials may depend on identifying patients as early as possible to maximize the number of treatable rods.
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The Role of Fundus Autofluorescence in Late-Onset Retinitis Pigmentosa (LORP) Diagnosis.
Ophthalmic Genet.
PUBLISHED: 07-30-2013
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Abstract Purpose: To demonstrate the utility and characteristics of fundus autofluorescence in late-onset retinitis pigmentosa. Methods: Observational case series. Patients diagnosed with late-onset retinitis pigmentosa were identified retrospectively in an institutional setting. Twelve eyes of six patients were identified and medical records were reviewed. Results: All patients presented with slowly progressive peripheral field loss and initial clinical examination revealed only subtle retinal changes. There was a notable lack of intraretinal pigment migration in all patients. Five out of six patients underwent magnetic resonance imaging of the brain to rule out intracranial processes and all were referred from another ophthalmologist for further evaluation. Fundus autofluorescence was ultimately employed in all patients and revealed more extensive retinal pathology than initially appreciated on clinical examination. Fundus autofluorescence directed the workup toward a retinal etiology in all cases and led to the eventual diagnosis of late-onset retinitis pigmentosa through electroretinogram testing. Conclusion: Fundus autofluorescence may be a more sensitive marker for retinal pathology than stereo fundus biomicroscopy alone in late-onset retinitis pigmentosa. Early use of fundus autofluorescence imaging in the evaluation of patients with subtle retinal lesions and complaints of peripheral field loss may be an effective strategy for timely and cost-efficient diagnosis.
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Comparison of fundus autofluorescence between fundus camera and confocal scanning laser ophthalmoscope-based systems.
Ophthalmic Surg Lasers Imaging Retina
PUBLISHED: 07-15-2013
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To compare fundus autofluorescence (FAF) imaging via fundus camera (FC) and confocal scanning laser ophthalmoscope (cSLO).
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Origin of fundus hyperautofluorescent spots and their role in retinal degeneration in a mouse model of Goldmann-Favre syndrome.
Dis Model Mech
PUBLISHED: 07-04-2013
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Goldmann-Favre syndrome, also known as enhanced S-cone syndrome, is an inherited retinal degeneration disease in which a gain of photoreceptor cell types results in retinal dysplasia and degeneration. Although microglia have been implicated in the pathogenesis of many neurodegenerative diseases, the fundamental role of these cells in this disease is unknown. In the current study, sequential analyses suggest that microglia are recruited and appear after outer nuclear layer folding. By crossing rd7 mice (a model for hereditary retinal degeneration owing to Nr2e3 mutation) with mice carrying the macrophage Fas-induced apoptosis (Mafia) transgene, we generated double-mutant mice and studied the role of the resident retinal microglia. Microglial cells in these double-mutant mice express enhanced green fluorescent protein (EGFP) and a suicide gene that can trigger Fas-mediated apoptosis via systemic treatment with AP20187 (FK506 dimerizer). We demonstrated that more than 80% of the EGFP+ cells in retinas from rd7/rd7;Tg/Tg mice express Iba-1 (a microglial marker), and resident microglia are still present in the retina because AP20187 does not cross the blood-brain barrier. Hence, only circulating bone marrow (BM)-derived microglia are depleted. Depletion of circulating BM-derived microglia accelerates retinal degeneration in rd7 mice. An increased number of autofluorescent (AF) spots is a consequence of resident microglia proliferation, which in turn establishes an inflammatory cytokine milieu via the upregulation of IL-1?, IL-6 and TNF? expression. This inflammation is likely to accelerate retinal degeneration. This study not only identifies inflammation as a crucial step in the pathogenesis of retinal degeneration, but also highlights the involvement of specific cytokine genes that could serve as future treatment targets in retinal degenerations.
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Disease progression in autosomal dominant cone-rod dystrophy caused by a novel mutation (D100G) in the GUCA1A gene.
Doc Ophthalmol
PUBLISHED: 06-13-2013
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To document longitudinal fundus autofluorescence (FAF) and electroretinogram (ERG) findings in a family with cone-rod dystrophy (CRD) caused by a novel missense mutation (D100G) in the GUCA1A gene.
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A biorepository for ophthalmic surgical specimens.
Proteomics Clin Appl
PUBLISHED: 06-12-2013
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Biorepositories are collections of surgically obtained human tissues for current and future investigations of disease mechanisms, therapeutics, and diagnostics. In ophthalmology, a critical challenge is how to interface the operating room with the laboratory. To attain standards required for basic research, clinical and research teams must cooperate to collect, annotate, and store specimens that yield consistent results required for advanced molecular techniques. We developed an efficient platform for obtaining vitreous and other eye tissues from the operating room and transferring them to the lab. The platform includes a mobile lab cart for on-site tissue processing, a multi-user, web-based database for point-of-care phenotypic capture, and an integrated data tracking system for long-term storage. These biorepository instruments have proven essential for our studies in ophthalmic disease proteomics. This system can be implemented in other operating rooms and laboratories for a variety of biological tissues.
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Outer retinal tubulation in degenerative retinal disorders.
Retina (Philadelphia, Pa.)
PUBLISHED: 05-17-2013
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To demonstrate outer retinal tubulation (ORT) in various degenerative retinal disorders.
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Unilateral retinopathy secondary to occult primary intraocular lymphoma.
Doc Ophthalmol
PUBLISHED: 05-13-2013
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The purpose of the study is to report the clinical case of a 53-year-old woman whose presenting manifestation of primary intraocular lymphoma (PIOL) was unilateral retinal degeneration.
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Evaluation of multimodal imaging in carriers of X-linked retinitis pigmentosa.
Exp. Eye Res.
PUBLISHED: 04-26-2013
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The aim of this study was to investigate visualization of the tapetal-like reflex using current imaging modalities and evaluate SD-OCT changes in known carriers of X-linked retinitis pigmentosa (XLRP); the objective being the development of an optimal protocol for clinicians to identify carriers. Ten XLRP carriers (19 eyes) were examined using color fundus photography, 488 nm reflectance (488-R), near-infrared reflectance (NIR-R), autofluorescence (AF) and spectral domain optical coherence tomography (SD-OCT) imaging (Spectralis SLO-OCT, Heidelberg). Horizontal line scans through the fovea were acquired in all subjects and in a group of 10 age-similar controls. Peripheral SD-OCT scans (extending to 27.5° eccentricity) were also acquired in both eyes of 7 carriers. MP-1 microperimetery (10-2 pattern; Nidek) was performed in one eye of each carrier. For the XLRP carriers, a tapetal reflex was observed with all imaging modalities in 8 of 19 eyes. It had the same retinal location on color fundus, 488-R and NIR-R imaging but a different location on AF. The tapetal reflex was most easily detected in 488-R images. The horizontal foveal SD-OCT scans were qualitatively normal, but measurements showed significant outer retinal layer thinning in all eyes. Additionally, the 14 eyes with peripheral SD-OCTs demonstrated patchy loss of the inner segment ellipsoid band. Microperimetry exhibited patchy visual sensitivity loss in 9 eyes. Full field ERGs were variable, ranging from normal to severely abnormal rod and cone responses. Our findings suggest that an optimal protocol for identifying carriers of XLRP should include 488-R imaging in a multimodal approach. Peripheral SD-OCT imaging and central retinal layer quantification revealed significant structural abnormalities.
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Genome-wide generation and systematic phenotyping of knockout mice reveals new roles for many genes.
Cell
PUBLISHED: 03-14-2013
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Mutations in whole organisms are powerful ways of interrogating gene function in a realistic context. We describe a program, the Sanger Institute Mouse Genetics Project, that provides a step toward the aim of knocking out all genes and screening each line for a broad range of traits. We found that hitherto unpublished genes were as likely to reveal phenotypes as known genes, suggesting that novel genes represent a rich resource for investigating the molecular basis of disease. We found many unexpected phenotypes detected only because we screened for them, emphasizing the value of screening all mutants for a wide range of traits. Haploinsufficiency and pleiotropy were both surprisingly common. Forty-two percent of genes were essential for viability, and these were less likely to have a paralog and more likely to contribute to a protein complex than other genes. Phenotypic data and more than 900 mutants are openly available for further analysis. PAPERCLIP:
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Mcph1-deficient mice reveal a role for MCPH1 in otitis media.
PLoS ONE
PUBLISHED: 01-31-2013
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Otitis media is a common reason for hearing loss, especially in children. Otitis media is a multifactorial disease and environmental factors, anatomic dysmorphology and genetic predisposition can all contribute to its pathogenesis. However, the reasons for the variable susceptibility to otitis media are elusive. MCPH1 mutations cause primary microcephaly in humans. So far, no hearing impairment has been reported either in the MCPH1 patients or mouse models with Mcph1 deficiency. In this study, Mcph1-deficient (Mcph1(tm1a) (/tm1a) ) mice were produced using embryonic stem cells with a targeted mutation by the Sanger Institutes Mouse Genetics Project. Auditory brainstem response measurements revealed that Mcph1(tm1a) (/tm1a) mice had mild to moderate hearing impairment with around 70% penetrance. We found otitis media with effusion in the hearing-impaired Mcph1(tm1a) (/tm1a) mice by anatomic and histological examinations. Expression of Mcph1 in the epithelial cells of middle ear cavities supported its involvement in the development of otitis media. Other defects of Mcph1(tm1a) (/tm1a) mice included small skull sizes, increased micronuclei in red blood cells, increased B cells and ocular abnormalities. These findings not only recapitulated the defects found in other Mcph1-deficient mice or MCPH1 patients, but also revealed an unexpected phenotype, otitis media with hearing impairment, which suggests Mcph1 is a new gene underlying genetic predisposition to otitis media.
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Cellular imaging demonstrates genetic mosaicism in heterozygous carriers of an X-linked ciliopathy gene.
Eur. J. Hum. Genet.
PUBLISHED: 01-24-2013
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X-linked retinitis pigmentosa (XLRP) is the least common genetic type of retinitis pigmentosa; however, it has extremely devastating consequences to patients activities of daily living. RPGR and RP2 genes expressed in the photoreceptor sensory cilia are predominantly implicated in XLRP; however, the interpretation of genetic mutations and their correlation with clinical phenotypes remain unknown, and the role of these genes in photoreceptor cilia function is not completely elucidated. Therefore, we evaluated structural characteristics in five female obligate carriers of XLRP by using state-of-the-art non-invasive imaging methods, including adaptive optics (AO) scanning laser ophthalmoscopy (SLO). In all five carriers examined, qualitative and quantitative analyses by AO SLO imaging revealed a mosaic pattern of cone disruption, even in the absence of visual symptoms, normal visual acuity and normal macular thickness, on optical coherence tomography and mildly subnormal full-field cone electroretinographic findings. As the technique is sensitive to the level of a single cone, the ability to visualize the cone cells in vivo should be especially useful in other retinal diseases. In addition, further investigation of XLRP carriers may yield insight into how cone structures change over time and ultimately enable understanding of the role of RPGR and RP2 in cone cell survival.
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Choroidal thickness and biometric markers for the screening of lacquer cracks in patients with high myopia.
PLoS ONE
PUBLISHED: 01-22-2013
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Validation of choroidal thickness and other biometrics measured by spectral domain optical coherence tomography (SD-OCT) in predicting lacquer cracks formation in highly myopic eyes.
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Comparison of near-infrared and short-wavelength autofluorescence in retinitis pigmentosa.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 01-05-2013
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To compare near-infrared autofluorescence (NIR-AF) and short-wavelength (SW) AF in retinitis pigmentosa (RP) and assess their relationships to underlying retinal structure and visual function.
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shRNA knockdown of guanylate cyclase 2e or cyclic nucleotide gated channel alpha 1 increases photoreceptor survival in a cGMP phosphodiesterase mouse model of retinitis pigmentosa.
J. Cell. Mol. Med.
PUBLISHED: 12-13-2011
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In vertebrate rods, dark and light conditions produce changes in guanosine 3,5-cyclic monophosphate (cGMP) and calcium (Ca(2+) ) levels, which are regulated by the opposing function of several proteins. During the recovery of a bright flash, guanylate cyclase (GUCY) helps raise cGMP to levels that open cGMP-gated calcium sodium channels (CNG) to increase Na(+) and Ca(2+) influx in the outer segment. In contrast, light activates cGMP phosphodiesterase 6 (PDE6) causing rapid hydrolysis of cGMP, CNG closure, and reduced Na(+) and Ca(2+) levels. In?Pde6b?mouse models of retinitis pigmentosa (RP), photoreceptor death is preceded by abnormally high cGMP and Ca(2+) levels, likely because of continued synthesis of cGMP by guanylate cyclases and unregulated influx of Ca(2+) to toxic levels through CNG channels. To reverse the effects of?Pde6b?loss of function, we employed an shRNA knockdown approach to reduce the expression of?Gucy2e?or?Cnga1?in?Pde6b(H620Q) photoreceptors prior to degeneration.?Gucy2e- or?Cnga1-shRNA lentiviral-mediated knockdown GUCY2E and CNGA1 expression increase visual function and photoreceptor survival in?Pde6b(H620Q) mice. We demonstrated that effective knockdown of?GUCY2E?and?CNGA1?expression to counteract loss of PDE6 function may develop into a valuable approach for treating some patients with RP.
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Mouse eye enucleation for remote high-throughput phenotyping.
J Vis Exp
PUBLISHED: 12-01-2011
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The mouse eye is an important genetic model for the translational study of human ophthalmic disease. Blinding diseases in humans, such as macular degeneration, photoreceptor degeneration, cataract, glaucoma, retinoblastoma, and diabetic retinopathy have been recapitulated in transgenic mice.(1-5) Most transgenic and knockout mice have been generated by laboratories to study non-ophthalmic diseases, but genetic conservation between organ systems suggests that many of the same genes may also play a role in ocular development and disease. Hence, these mice represent an important resource for discovering new genotype-phenotype correlations in the eye. Because these mice are scattered across the globe, it is difficult to acquire, maintain, and phenotype them in an efficient, cost-effective manner. Thus, most high-throughput ophthalmic phenotyping screens are restricted to a few locations that require on-site, ophthalmic expertise to examine eyes in live mice. (6-9) An alternative approach developed by our laboratory is a method for remote tissue-acquisition that can be used in large or small-scale surveys of transgenic mouse eyes. Standardized procedures for video-based surgical skill transfer, tissue fixation, and shipping allow any lab to collect whole eyes from mutant animals and send them for molecular and morphological phenotyping. In this video article, we present techniques to enucleate and transfer both unfixed and perfusion fixed mouse eyes for remote phenotyping analyses.
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Disruption in Bruch membrane in patients with Stargardt disease.
Ophthalmic Genet.
PUBLISHED: 11-07-2011
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To describe the spectral domain-optical coherence tomography (SD-OCT) findings of two patients with complete defects in the retinal pigment epithelium (RPE) with disruptions in Bruch membrane in Stargardt disease (STGD1).
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Lentivirus-mediated expression of cDNA and shRNA slows degeneration in retinitis pigmentosa.
Exp. Biol. Med. (Maywood)
PUBLISHED: 09-01-2011
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Mutations in Pde6b lead to high levels of signaling molecules cyclic guanosine monophosphate (cGMP) and Ca(2+), which ultimately result in photoreceptor cell death in certain forms of retinitis pigmentosa (RP). The level of cGMP, which is controlled by opposing activities of guanylate cyclase (GUCY) and photoreceptor phosphodiesterase-6 (PDE6), regulates the opening of cyclic nucleotide-gated ion channels [CNG] and thereby controls Ca(2+) influx into the outer segments. Using a lentiviral gene therapy approach, we have previously shown that degeneration can be temporarily slowed either by introducing wild-type PDE6? or knocking down expression of GUCY2E and CNGA1 in photoreceptors of Pde6b(H620Q), a mouse model for RP. Rescue was transient with either approach. Therefore, we tested a novel combination therapy using bipartite lentiviral vectors designed to both introduce wild-type PDE6? expression and knockdown GUCY2E or CNGA1. Immunoblot analysis shows simultaneous increases in PDE6? and decreases in GUCY2E or CNGA1 in retinas transduced by the vectors, indicating successful transduction. In Pde6b(H620Q) mutants, we observe rescue of photoreceptor function and an increase in photoreceptor rows as compared with untreated controls. However, no evidence of prolonged rescue beyond the limit of the previously tested single therapy was observed.
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Effect of the ILE86TER mutation in the ? subunit of cGMP phosphodiesterase (PDE6) on rod photoreceptor signaling.
Cell. Signal.
PUBLISHED: 08-18-2011
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The light-dependent decrease in cyclic guanosine monophosphate (cGMP) in the rod outer segment is produced by a phosphodiesterase (PDE6), consisting of catalytic ? and ? subunits and two inhibitory ? subunits. The molecular mechanism of PDE6? regulation of the catalytic subunits is uncertain. To study this mechanism in vivo, we introduced a modified Pde6g gene for PDE6? into a line of Pde6g(tm1)/Pde6g(tm1) mice that do not express PDE6?. The resulting ILE86TER mice have a PDE6? that lacks the two final carboxyl-terminal Ile(86) and Ile(87) residues, a mutation previously shown in vitro to reduce inhibition by PDE6?. ILE86TER rods showed a decreased sensitivity and rate of activation, probably the result of a decreased level of expression of PDE6 in ILE86TER rods. More importantly, they showed a decreased rate of decay of the photoresponse, consistent with decreased inhibition of PDE6 ? and ? by PDE6?. Furthermore, ILE86TER rods had a higher rate of spontaneous activation of PDE6 than WT rods. Circulating current in ILE86TER rods that also lacked both guanylyl cyclase activating proteins (GCAPs) could be increased several fold by perfusion with 100?M of the PDE6 inhibitor 3-isobutyl-1-methylxanthine (IBMX), consistent with a higher rate of dark PDE6 activity in the mutant photoreceptors. In contrast, IBMX had little effect on the circulating current of WT rods, unlike previous results from amphibians. Our results show for the first time that the Ile(86) and Ile(87) residues are necessary for normal inhibition of PDE6 catalytic activity in vivo, and that increased basal activity of PDE can be partially compensated by GCAP-dependent regulation of guanylyl cyclase.
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Progressive constriction of the hyperautofluorescent ring in retinitis pigmentosa.
Am. J. Ophthalmol.
PUBLISHED: 04-24-2011
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To evaluate the constriction of the hyperautofluorescent ring over time in patients with retinitis pigmentosa (RP).
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Allelic and phenotypic heterogeneity in ABCA4 mutations.
Ophthalmic Genet.
PUBLISHED: 04-21-2011
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Since the discovery of the ABCA4 gene as the cause of autosomal recessive Stargardt disease/fundus flavimaculatus much has been written of the phenotypic variability in ABCA4 retinopathy. In this review the authors discuss the findings seen on examination and the disease features detected using various clinical tests. Important differential diagnoses are presented and unusual presentations of ABCA4 disease highlighted.
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Evisceration of mouse vitreous and retina for proteomic analyses.
J Vis Exp
PUBLISHED: 04-15-2011
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While the mouse retina has emerged as an important genetic model for inherited retinal disease, the mouse vitreous remains to be explored. The vitreous is a highly aqueous extracellular matrix overlying the retina where intraocular as well as extraocular proteins accumulate during disease.(1-3) Abnormal interactions between vitreous and retina underlie several diseases such as retinal detachment, proliferative diabetic retinopathy, uveitis, and proliferative vitreoretinopathy.(1,4) The relative mouse vitreous volume is significantly smaller than the human vitreous (Figure 1), since the mouse lens occupies nearly 75% of its eye.(5) This has made biochemical studies of mouse vitreous challenging. In this video article, we present a technique to dissect and isolate the mouse vitreous from the retina, which will allow use of transgenic mouse models to more clearly define the role of this extracellular matrix in the development of vitreoretinal diseases.
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Function of the asparagine 74 residue of the inhibitory ?-subunit of retinal rod cGMP-phophodiesterase (PDE) in vivo.
Cell. Signal.
PUBLISHED: 04-07-2011
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The inhibitory subunit of rod cyclic guanosine monophosphate (cGMP) phosphodiesterase, PDE6?, is a major component of rod transduction and is required to support photoreceptor integrity. The N74A allele of PDE6? has previously been shown in experiments carried out in vitro to reduce the regulatory inhibition on the PDE6 catalytic core subunits, PDE6??. This should, in intact rods, lead to an increase in basal (dark) PDE6 activity producing a state equivalent to light adaptation in the rods and we have examined this possibility using ERG and suction-electrode measurements. The murine opsin promoter was used to drive the expression of a mutant N74A and a wild-type PDE6? control transgene in the photoreceptors of +/Pde6g(tm1) mice. This transgenic line was crossed with Pde6g(tm1)/Pde6g(tm1) mice to generate animals able to synthesize only the transgenic mutant PDE6?. We find that the N74A mutation did not produce a significant decrease in circulating current, a decrease in sensitivity or affect the kinetics of the light response, all hallmarks of the light-adapted state. In an in vitro assay of the PDE purified from the N74A transgenic mice and control mice we could find no increase in basal activity of the mutant PDE6. Both the results from the physiology and the biochemistry experiments are consistent with the interpretation that the mutation causes a much milder phenotype in vivo than was predicted from observations made using a cell-free assay system. The in vivo regulation of PDE6? on PDE6?? may be more dynamic and context-dependent than was replicated in vitro.
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Autofluorescence imaging and spectral-domain optical coherence tomography in incomplete congenital stationary night blindness and comparison with retinitis pigmentosa.
Am. J. Ophthalmol.
PUBLISHED: 03-26-2011
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To test the hypothesis that the evaluation of retinal structure can have diagnostic value in differentiating between incomplete congenital stationary night blindness (CSNB2) and retinitis pigmentosa (RP). To compare retinal thickness differences between patients with CSNB2 and myopic controls.
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Macular dystrophy in Heimler syndrome.
Ophthalmic Genet.
PUBLISHED: 03-02-2011
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To describe the retinal imaging findings in the index patient with Heimler syndrome (OMIM #234580).
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The inner segment/outer segment border seen on optical coherence tomography is less intense in patients with diminished cone function.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 01-01-2011
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PURPOSE; The integrity of the inner segment ellipsoid (ISe) band, previously called the inner segment/outer segment (IS/OS) border, seen on optical coherence tomography (OCT) scans is of clinical significance. To better understand the influence of cones on the appearance of this band, the intensity of its signal in patients with diminished cone function was examined.
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Analysis of the ABCA4 gene by next-generation sequencing.
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 01-01-2011
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To find all possible disease-associated variants in coding sequences of the ABCA4 gene in a large cohort of patients diagnosed with ABCA4-associated diseases.
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Quantification of peripapillary sparing and macular involvement in Stargardt disease (STGD1).
Invest. Ophthalmol. Vis. Sci.
PUBLISHED: 01-01-2011
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To quantify and compare structure and function across the macula and peripapillary area in Stargardt disease (STGD1).
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Unilateral electronegative ERG in a presumed central retinal artery occlusion.
Clin Ophthalmol
PUBLISHED: 11-17-2010
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A unilateral electronegative electroretinogram (ERG) was seen in a 94-year-old man with presumed central retinal artery occlusion. Goldmann perimetry revealed central scotoma in the right eye and no abnormalities in the left eye. Full-field ERG in the right eye described a reduction of the b-wave with a relative preservation of the a-wave which is characteristic of electronegative ERG. Hence, our case illustrates that ERG testing is essential for the work-up of individuals with suspected retinal vascular disorders.
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Choroideremia in a woman with ectodermal dysplasia and complex translocations involving chromosomes X, 1, and 3.
Ophthalmic Genet.
PUBLISHED: 11-12-2010
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Choroideremia is an X-linked recessive disorder characterized by vision loss with progressive atrophy of the retinal photoreceptors, retinal pigment epithelium (RPE), and choriocapillaris. Ectodermal dysplasia is a heterogeneous group of disorders characterized by a deficiency of two or more ectodermal derivatives. We report on the phenotypic and genetic characteristics of a 29-year-old woman with both choroideremia and ectodermal dysplasia.
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Loss of peripapillary sparing in non-group I Stargardt disease.
Exp. Eye Res.
PUBLISHED: 06-16-2010
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The aim of this study was to assess peripapillary sparing in patients with non-group I Stargardt disease. We suggest this as a useful clinical sign for formulating disease severity. Patients with a diagnosis of Stargardt disease were grouped by electroretinogram (ERG). Fundus autofluorescence was used to assess the peripapillary area for involvement in the Stargardt disease process. From a cohort of 32 patients (64 eyes), 17 patients (33 eyes) demonstrated loss of peripapillary sparing. One of 15 patients in Group I, six of 7 patients in group II and 9 of 10 patients in group III demonstrated peripapillary atrophy. One patient in group II had peripapillary flecks. All patients had at least one mutation detected in the ABCA4 gene. Both mutations were detected in 21 patients. Patients in groups II and III had the earliest ages of onset and the poorest visual acuities. Two novel disease causing mutation in the ABCA4 gene were detected. Our data supports the observation that peripapillary sparing is not universal finding for Stargardt disease and peripapillary atrophy is a useful clinical sign for identifying patients with Stargardt disease who fall into the more severe ERG groups, i.e. groups II and III. The presence of atrophy suggests a continuum of disease between groups II and III. Loss of peripapillary sparing is likely associated with the more deleterious mutations of the ABCA4 gene.
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Fundus autofluorescence and optical coherence tomography of congenital grouped albinotic spots.
Retina (Philadelphia, Pa.)
PUBLISHED: 06-12-2010
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The purpose of this study was to describe the findings of fundus autofluores-cence (FAF) and optical coherence tomography in a series of patients with congenital grouped albinotic spots.
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Autofluorescence and High-Resolution OCT Findings Revealed Ciliopathy in Senior-Loken Syndrome.
Ophthalmic Surg Lasers Imaging
PUBLISHED: 03-27-2010
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To describe novel findings on fundus autofluorescence (FAF) and high-resolution optical coherence tomography (OCT) in a 27-year-old woman with the Senior-Loken syndrome (SLSN) emphasizing the photoreceptors cilia appearance in the macula. The patient had renal transplantation early in life and poor visual acuity due to advanced autosomal recessive retinitis pigmentosa. FAF showed diffuse spots of decreased autofluorescence in the mid-periphery and a perifoveal ring of increased autofluorescence suggesting a bulls eye maculopathy. High-resolution OCT revealed a barely detectable inner-outer photoreceptor segment junction in the central macula corresponding to the area inside of the ring of increased autofluorescence, suggesting initial ciliary junction disorganization before photoreceptors death. Non-invasive technologies can monitor central photoreceptors cilliary anatomy enabling early detection of cell disorganization in diseases involving ciliopathy such as the Senior-Loken syndrome are concluded.
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Fundus autofluorescence, optical coherence tomography, and electroretinogram findings in choroidal sclerosis.
Retina (Philadelphia, Pa.)
PUBLISHED: 03-13-2010
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The purpose of this study was to describe fundus autofluorescence (FAF), optical coherence tomography, and electroretinogram findings in choroidal sclerosis.
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Transplantation of reprogrammed embryonic stem cells improves visual function in a mouse model for retinitis pigmentosa.
Transplantation
PUBLISHED: 02-19-2010
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To study whether C57BL/6J-Tyr/J (C2J) mouse embryonic stem (ES) cells can differentiate into retinal pigment epithelial (RPE) cells in vitro and then restore retinal function in a model for retinitis pigmentosa: Rpe65/Rpe65 C57BL6 mice.
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Autofluorescence imaging in rubella retinopathy.
Ocul. Immunol. Inflamm.
PUBLISHED: 12-17-2009
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To demonstrate that fundus autofluorescence (FAF) imaging aides the diagnosis of rubella retinopathy (RR).
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Erythropoetin receptor expression in the human diabetic retina.
BMC Res Notes
PUBLISHED: 11-09-2009
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Recent evidence suggests erythropoietin (EPO) and the erythropoietin receptor (EPOR) may play a direct role in the pathogenesis of diabetic retinopathy. Better characterization of the EPO-EPOR signaling system in the ischemic retina may offer a new therapeutic modality for ischemic ophthalmic diseases. This study was performed to identify EPOR mRNA expression in the human diabetic eye.
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Light-dependent phosphorylation of the gamma subunit of cGMP-phophodiesterase (PDE6gamma) at residue threonine 22 in intact photoreceptor neurons.
Biochem. Biophys. Res. Commun.
PUBLISHED: 10-17-2009
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The gamma subunit of rod-specific cGMP phosphodiesterase 6 (PDE6gamma), an effector of the G-protein GNAT1, is a key regulator of phototransduction. The results of several in vitro biochemical reconstitution experiments conducted to examine the effects of phosphorylation of PDE6gamma on its ability to regulate the PDE6 catalytic core have been inconsistent, showing that phosphorylation of PDE6gamma may increase or decrease the ability of PDE6gamma to deactivate phototransduction. To resolve role of phosphorylation of PDE6gamma in living photoreceptors, we generated transgenic mice in which either one or both Threonine (T) sites in PDE6gamma (T22 and T35), which are candidates for putative regulatory phosphorylation, were substituted with alanine (A). Phosphorylation of these sites was examined as a function of light exposure. We found that phosphorylation of T22 increases with light exposure in intact mouse rods while constitutive phosphorylation of T35 is unaffected by light in intact mouse rods and cones. Phosphorylation of the cone isoform of PDE6gamma, PDE6H, is constitutively phosphorylated at the T20 residue. Light-induced T22 phosphorylation was lost in T35A transgenic rods, and T35 phosphorylation was extinguished in T22A transgenic rods. The interdependency of phosphorylation of T22 and T35 suggests that light-induced, post-translational modification of PDE6gamma is essential for the regulation of G-protein signaling.
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Structural assessment of hyperautofluorescent ring in patients with retinitis pigmentosa.
Retina (Philadelphia, Pa.)
PUBLISHED: 07-09-2009
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To analyze the retinal structure underlying the hyperautofluorescent ring visible on fundus autofluorescence in patients with retinitis pigmentosa.
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What is Visualize?

JoVE Visualize is a tool created to match the last 5 years of PubMed publications to methods in JoVE's video library.

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In developing our video relationships, we compare around 5 million PubMed articles to our library of over 4,500 methods videos. In some cases the language used in the PubMed abstracts makes matching that content to a JoVE video difficult. In other cases, there happens not to be any content in our video library that is relevant to the topic of a given abstract. In these cases, our algorithms are trying their best to display videos with relevant content, which can sometimes result in matched videos with only a slight relation.