ORCID Profile
0000-0002-8391-6123
Current Organisations
Moorfields Eye Hospital NHS Foundation Trust
,
University College London
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Publisher: Springer Science and Business Media LLC
Date: 06-04-2021
DOI: 10.1007/S00417-021-05100-8
Abstract: Visual outcomes after cataract surgery in diabetic patients with retinal or visual pathway disease are difficult to predict as the fundus may be obscured, and assessment of visual potential is challenging. This study assessed the value of visual electrophysiology as a prognostic indicator of visual recovery in diabetic patients with cataract, prior to cataract surgery. Forty-one diabetic patients (aged 52–80 74 eyes) and 13 age-matched non-diabetic control patients (21 eyes) were examined prior to cataract surgery. Pre-surgical examinations included best-corrected visual acuity (BCVA), slit-l bio-microscopy, ISCEV-standard full-field electroretinography (ffERG), and flash visual evoked potential (flash VEP) testing. Electrophysiological assessments included quantification of the DA and LA ERG, oscillatory potentials (OPs OP1, OP2, OP3, OP4) and flash VEP P1, P2, and P3 components. Post-operative BCVA was measured in all cases and the diabetic patients grouped according to the severity of visual acuity loss: mild (logMAR ≤ 0.1), moderate (0.1 logMAR 0.5), or severe (logMAR ≥ 0.5). A fourth group included those without diabetes. The pre-surgical electrophysiological data was compared between the four groups by analysis of variance. The severity of post-surgical visual acuity loss in the diabetic patients was classified as mild ( N =22 eyes), moderate ( N =31 eyes), or severe ( N =21 eyes). In the group without diabetes, post-surgical visual impairment was classified as mild ( N =21 eyes). The pre-operative DA 10.0 ERG a-wave litudes, DA 3.0 ERG OP2 litudes, and the LA 3.0 a- and b-wave litudes showed best significant differences among the four groups. The flash VEP did not show significant difference between groups. Electrophysiological assessment of diabetic patients with cataract can provide a useful measure of retinal function. Full-field ERG components, including the DA 10.0 ERG a-wave, DA 3.0 ERG OP2 component, and the LA 3.0 a- and b-wave litudes, are of prognostic value in predicting post-surgical visual acuity, and may inform the surgical management of cataract patients with diabetes.
Publisher: Elsevier BV
Date: 02-2012
Publisher: Informa UK Limited
Date: 22-05-2017
Publisher: Hindawi Limited
Date: 17-10-2017
DOI: 10.1002/HUMU.23349
Abstract: Retinal dystrophies are a heterogeneous group of disorders of visual function leading to partial or complete blindness. We report the genetic basis of an unusual retinal dystrophy in five families with affected females and no affected males. Heterozygous missense variants were identified in the X-linked phosphoribosyl pyrophosphate synthetase 1 (PRPS1) gene: c.47C > T, p.(Ser16Phe) c.586C > T, p.(Arg196Trp) c.641G > C, p.(Arg214Pro) and c.640C > T, p.(Arg214Trp). Missense variants in PRPS1 are usually associated with disease in male patients, including Arts syndrome, Charcot-Marie-Tooth, and nonsyndromic sensorineural deafness. In our study families, affected females manifested a retinal dystrophy with interocular asymmetry. Three unrelated females from these families had hearing loss leading to a diagnosis of Usher syndrome. Other neurological manifestations were also observed in three in iduals. Our data highlight the unexpected X-linked inheritance of retinal degeneration in females caused by variants in PRPS1 and suggest that tissue-specific skewed X-inactivation or variable levels of pyrophosphate synthetase-1 deficiency are the underlying mechanism(s). We speculate that the absence of affected males in the study families suggests that some variants may be male embryonic lethal when inherited in the hemizygous state. The unbiased nature of next-generation sequencing enables all possible modes of inheritance to be considered for association of gene variants with novel phenotypic presentation.
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 08-2009
DOI: 10.1167/IOVS.08-2715
Abstract: To correlate the phenotype of four patients with inherited macular disease with the immunohistopathology of retinal tissue collected at the time of retinal pigment epithelium (RPE)-choroidal transplantation. A clinicopathologic case series describing the phenotype of four patients, including confocal immunohistochemistry and electron microscopy (EM), and the results of genetic testing. In Case 1, electrophysiology showed only macular dysfunction. Confocal microscopy revealed minor abnormalities. EM showed abnormal cone inner segments with swollen mitochondria. In case 2 (R172W mutation in RDS), electrophysiology demonstrated generalized cone system dysfunction with severe macular involvement. Peripherin labeling of outer segments was nonuniform, and EM showed discs arranged in whorllike structures. Case 3 showed severe central macular dysfunction on multifocal electroretinogram (ERG). Peripherin staining was irregular and disorganized. EM revealed abnormal inner segment morphology, particularly in rods, and disorganized irregular outer segments. Case 4 had localized central macular dysfunction on multifocal ERG. Confocal microscopy was grossly normal, with evidence of early redistribution of cone opsin to the inner segment. EM showed variable rod morphology and normal cones. RPE transplantation provides a unique opportunity to gain insight into retinal disorders by enabling phenotypic correlation with the immunohistopathology of retinal tissue collected during surgery.
Publisher: Public Library of Science (PLoS)
Date: 06-03-2012
Publisher: Elsevier BV
Date: 05-2014
Publisher: Springer Science and Business Media LLC
Date: 21-01-2017
DOI: 10.1007/S10633-017-9573-2
Abstract: The clinical electro-oculogram (EOG) is an electrophysiological test of the outer retina and retinal pigment epithelium (RPE) in which changes in the electrical potential across the RPE are recorded during successive periods of dark and light adaptation. This document presents the 2017 EOG Standard from the International Society for Clinical Electrophysiology of Vision (ISCEV: www.iscev.org ). This standard has been reorganized and updated to include an explanation of the mechanism of the EOG, but without substantive changes to the testing protocol from the previous version published in 2011. It describes methods for recording the EOG in clinical applications and gives detailed guidance on technical requirements, practical issues and reporting of results with the main clinical measure (the Arden ratio) now termed the light peak:dark trough ratio. The standard is intended to promote consistent quality of testing and reporting within and between clinical centers.
Publisher: Springer Science and Business Media LLC
Date: 09-03-2017
Publisher: Elsevier BV
Date: 02-2017
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 25-06-2012
DOI: 10.1167/IOVS.12-9548
Abstract: To report novel variants and characterize the phenotype associated with the autosomal recessive retinal dystrophy caused by mutations in the lecithin retinol acyltransferase (LRAT) gene. A total of 149 patients with Leber's congenital amaurosis (LCA) or early onset retinal dystrophy were screened for mutations in LCA-associated genes using an arrayed-primer extension (APEX) genotyping microarray (Asper Ophthalmics). LRAT sequencing was subsequently performed in this 148-patient panel. Patients identified with mutations underwent further detailed phenotyping. APEX analysis identified one patient with a previously reported homozygous LRAT mutation. Sequencing of the panel identified three additional patients with novel homozygous LRAT mutations in exon 2. All four patients had severe progressive nyctalopia, visual field constriction, and photophilia in childhood. Visual acuity ranged from 0.22 logMAR to hand motion. Funduscopy revealed severe retinal pigment epithelial atrophy and minimal retinal pigmentation. Asteroid hyalosis and macular epiretinal fibrosis were frequent. All demonstrated reduced fundus autofluorescence. Optical coherence tomography identified disrupted retinal lamination, outer-retinal debris, and an unidentifiable photoreceptor layer in two cases. Full-field electroretinograms were undetectable or showed severe rod-cone dysfunction. Photopic perimetry revealed severe visual field constriction. Dark-adapted perimetry demonstrated markedly reduced photoreceptor sensitivity. Dark-adapted spectral sensitivity measurements identified functioning rods in two of three patients. All three had severely reduced L- and M-cone sensitivity and poor color discrimination. LRAT mutations cause a severe, early childhood onset, progressive retinal dystrophy. Phenotypic similarities to the retinal dysfunction associated with RPE-specific protein 65 kDa mutations, another visual cycle gene, suggest that LRAT deficiency may show a good response to novel therapies.
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 09-05-2011
DOI: 10.1167/IOVS.10-7025
Abstract: To investigate the prevalence of sequence variants in the gene SPATA7 in patients with Leber congenital amaurosis (LCA) and autosomal recessive, severe, early-onset retinal dystrophy (EORD) and to delineate the ocular phenotype associated with SPATA7 mutations. Patients underwent standard ophthalmic evaluation after providing informed consent. One hundred forty-one DNA s les from patients with LCA and EORD had been analyzed for mutations by using a microarray, with negative results. One additional patient underwent SPATA7 screening due to a region of autozygosity surrounding this gene. A further patient was screened who had a compatible ocular phenotype. The entire SPATA7 coding sequence was assayed, including the intron-exon junctions, by using a combination of direct DNA sequencing and high-resolution melting screening. Screening of SPATA7 identified several known and novel single-nucleotide polymorphisms (SNPs). Affected in iduals from five unrelated families were identified to have coding changes. Clinical features demonstrated a severe infantile onset retinal dystrophy, similar to Leber congenital amaurosis. The retina had widespread retinal pigment epithelial atrophy, with minimal pigment migration into the neurosensory retina. Fundus autofluorescence imaging showed a parafoveal annulus of increased autofluorescence. High-definition optical coherence tomography showed preservation of the inner segment/outer segment junction at the fovea. Mutations in SPATA7 are a rare cause of childhood retinal dystrophy accounting for 1.7% of disease in this cohort. Affected patients present in infancy with severe visual loss, but may have some preservation of the photoreceptor structure in the central retina.
Publisher: Association for Research in Vision and Ophthalmology (ARVO)
Date: 15-06-2022
DOI: 10.1167/IOVS.63.6.15
Publisher: Springer Science and Business Media LLC
Date: 14-03-2018
Publisher: BMJ
Date: 17-10-2010
Abstract: To identify CRB1 mutations in a large cohort of patients with recessive retinal dystrophies and to document the retinal phenotype and visual prognosis. A hospital-based cross-sectional study of children and adults with recessive retinal dystrophies. Three hundred and six patients with Leber congenital amaurosis (LCA), early-onset childhood retinal dystrophy or juvenile onset retinitis pigmentosa were recruited to the study and gave blood s les for molecular genetic analysis. A detailed clinical examination was performed, including: logMAR visual acuity, refraction, Goldmann visual fields, slit-l biomicroscopy, fundus photography, autofluorescence imaging and optical coherence tomography. The results of electrophysiology testing were available in all patients. DNA was obtained for molecular genetic analysis. Initial screening for mutations was performed using the LCA chip. Patients who had one or more CRB1 mutations identified on the chip, and other patients whose phenotype suggested a CRB1 genotype, underwent direct sequencing. In addition, consanguineous families segregating recessive RP underwent a whole genome scan using Affymetrix gene chips, and affected family members showing linkage to the RP12 locus underwent sequencing of the CRB1 gene. Identification of patients with mutations in CRB1 and detailed documentation of the clinical phenotype. Mutations in CRB1, including 17 novel mutations, were identified in 41 patients from 32 families. The authors identified both disease mutations in 34 patients from 26 families, and these patients underwent detailed phenotyping. Common phenotypic features included hypermetropic refractive error, nummular pigmentation at the level of the RPE and increased retinal thickness on optical coherence tomography. Most patients had a clinical and electrophysiological phenotype consistent with a diagnosis of LCA or rod-cone dystrophy, but three patients had electroretinogram evidence of cone-rod degeneration. A minority of patients developed peripheral retinal telangiectasia, which in some cases led to seclusio pupillae and angle-closure glaucoma. Mutations in CRB1 are associated with a range of recessively inherited retinal dystrophies, including LCA, childhood- and juvenile-onset rod-cone and cone-rod dystrophies. Although the phenotype is usually severe, in milder cases there is a window of opportunity for therapeutic intervention in early childhood.
Publisher: American Medical Association (AMA)
Date: 02-2017
DOI: 10.1001/JAMAOPHTHALMOL.2016.5213
Abstract: There are limited published data on the phenotype of retinitis pigmentosa (RP) related to CNGB1 variants. These data are needed both for prognostic counseling of patients and for understanding potential treatment windows. To describe the detailed clinical and molecular genetic findings in a series of patients with RP with likely pathogenic variants in CNGB1. In this case series, 10 patients from 9 families underwent full ophthalmologic examination. Molecular investigations included whole-exome analysis in 6 patients. The study was conducted from April 17, 2013, to March 3, 2016, with final follow-up completed on March 2, 2016, and data were analyzed from October 27, 2014, to March 29, 2016. Results of ophthalmologic examination and molecular genetic analysis of CNGB1. In this case series, 7 women and 3 men from 9 families with a mean (SD) age of 47.4 (13.2) years identified as having CNGB1 variants were included in this study there was a mean (SD) follow-up length of 3.7 (2.8) years. The first clinical presentation was with nyctalopia in childhood with visual field loss documented later at a mean (SD) age of 33.2 (8.0) years. All patients had preserved best-corrected visual acuity into adulthood, with a mean of 0.1 logMAR (Snellen equivalent, 20/25) in each eye (logMAR range, 0.0 to 0.3 [Snellen 20/20 to 20/40] in the right eye and -0.1 to 0.3 [Snellen 20/16 to 20/40] in the left eye). Fundus examination revealed midperipheral retinal pigment epithelial atrophy and intraretinal pigment migration. Optical coherence tomography of the macula demonstrated complete preservation of the inner segment ellipsoid band in 1 patient, with variable lateral extent in the other patients corresponding to the diameter of a paracentral ring of increased fundus autofluorescence. Electrophysiologic testing in 6 patients confirmed a rod-cone dystrophy phenotype. Molecular investigations identified a previously reported missense variant (p.[N986I]) and 7 variants not previously reported in disease including 4 nonsense (p.[(Q88*], p.[Q222*], p.[Q318*], and p.[R729*]), 2 frameshift (p.[A1048fs*13], p.[L849Afs*3]), and a splice site variant (c.761 + 2T>A). The data from this study suggest that visual acuity and foveal structure in patients with RP are preserved into adult life such that a lengthy window of opportunity should exist for intervention with novel therapies.
Publisher: Springer Science and Business Media LLC
Date: 05-05-2022
DOI: 10.1007/S10633-022-09872-0
Abstract: The full-field electroretinogram (ERG) is a mass electrophysiological response to diffuse flashes of light and is used widely to assess generalized retinal function. This document, from the International Society for Clinical Electrophysiology of Vision (ISCEV), presents an updated and revised ISCEV Standard for clinical ERG testing. Minimum protocols for basic ERG stimuli, recording methods and reporting are specified, to promote consistency of methods for diagnosis, monitoring and inter-laboratory comparisons, while also responding to evolving clinical practices and technology. The main changes in this updated ISCEV Standard for clinical ERGs include specifying that ERGs may meet the Standard without mydriasis, providing stimuli adequately compensate for non-dilated pupils. There is more detail about analysis of dark-adapted oscillatory potentials (OPs) and the document format has been updated and supplementary content reduced. There is a more detailed review of the origins of the major ERG components. Several tests previously tabulated as additional ERG protocols are now cited as published ISCEV extended protocols. A non-standard abbreviated ERG protocol is described, for use when patient age, compliance or other circumstances preclude ISCEV Standard ERG testing.
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
Location: United Kingdom of Great Britain and Northern Ireland
No related grants have been discovered for Anthony Robson.