Marcela Votruba | Cardiff University (original) (raw)

Papers by Marcela Votruba

Research paper thumbnail of Guidelines for the use and interpretation of assays for monitoring autophagy

Autophagy, 2012

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since t... more In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

Research paper thumbnail of Inherited dominant optic neuropathy: from clinical studies to gene function and back again

Drug Discovery Today: Disease Models, 2013

Here we review how clinically driven research into the basic cellular function of the major deter... more Here we review how clinically driven research into the basic cellular function of the major determinant in autosomal dominant optic atrophy, Kjer's type (OPA1), has in turn, facilitated and inspired potential therapeutic endeavours in murine models. Dominant optic atrophy is one of the most frequent causes of inherited optic neuropathy and affects up to 1 in 35 000. Its underlying pathophysiology gives us a remarkable insight into mitochondrial function and how this impacts on neuronal cell survival in the retina.

Research paper thumbnail of Linkage analysis in english pedigrees with dominant optic atrophy

Vision Research, 1995

Abstract: PURPOSETo establish linkage for families with autosomal dominant optic atrophy and to d... more Abstract: PURPOSETo establish linkage for families with autosomal dominant optic atrophy and to determine whether there is any evidence for genetic heterogeneity. METHODSAfter examination patients were entered into the study if they fulfilled the criteria for autosomal dominant optic atrophy of onset in the first decade, blue-yellow dyschromatopsia and characteristic optic nerve pallor. RESULTSGenethon Microsatelite markers as described by Gyapay et al 1994 were used to map the region 3q-28-qter which has been linked to ...

Research paper thumbnail of Visual dysfunction and pupillary responses are dissociated in the Opa3 mutant mouse with retinal degeneration

Acta Ophthalmologica, 2014

ABSTRACT Purpose To assess the affect of the missense mutation p.L122P in a mouse model of 3-meth... more ABSTRACT Purpose To assess the affect of the missense mutation p.L122P in a mouse model of 3-methylglutaconic aciduria (MGA-III), a neuro-metabolic syndrome which presents with retinal and optic atrophy and neurological impairment.Methods Visual acuity was quantified in an optokinetic nystagmus drum by increasing the spatial frequency of the grating until an optomotor response could not be elicited. Pupillary light responsiveness was assessed by video pupillometry. Time course and phenotype of retinal degeneration was examined using haematoxylin and eosin and terminal dUTP transferase nick end labelling.Results Opa3+/+ and Opa3+/- mice showed normal visual acuity by tracking a 2° grating. However, Opa3-/- mice displayed no optomotor response at any grating frequency. Despite this, their pupil response was little affected. Pupil response/intensity curves of Opa3-/- and Opa3+/+ mice diverged somewhat at lower intensities although they only differed significantly at two irradiance levels. At 50% constriction Opa3-/- mice were only 0.61 log units less sensitive than wildtypes. Histology showed panretinal degeneration in adult Opa3-/- mice and TUNEL revealed increased cell death in postnatal and adult Opa3-/- retinae.Conclusion The Opa3-/- mouse is a useful model of the human disease. Retinal atrophy in Opa3-/- animals is associated with widespread retinal thinning. However, dissociation between visual perception and pupillary function implies that the intrinsically photosensitive retinal ganglion cells (ipRGCs) subserving pupillary function may be less susceptible to damage by mutations of Opa3 than the retinogeniculate fibres underlying visual perception.

Research paper thumbnail of A review of primary hereditary optic neuropathies

Journal of inherited metabolic disease, 2003

The primary inherited optic neuropathies are a heterogeneous group of disorders that result in lo... more The primary inherited optic neuropathies are a heterogeneous group of disorders that result in loss of retinal ganglion cells, leading to the clinical appearance of optic atrophy. They affect between 1:10,000 to 1:50,000 people. The main clinical features are a reduction in visual acuity, colour vision abnormalities, centro-caecal visual field defects and pallor of the optic nerve head. Electrophysiological testing shows a normal flash electroretinogram, absent or delayed pattern visually evoked potentials suggestive of a conduction deficit and N95 waveform reduction on the pattern electroretinogram, consistent with a primary ganglion cell pathology. The primary inherited optic neuropathies may be sporadic or familial. The mode of inheritance may be autosomal dominant, autosomal recessive, X-linked recessive or mitochondrial. Within each of these groups, the phenotypic characteristics vary in such features as the mode and age of onset, the severity of the visual loss, the colour def...

Research paper thumbnail of Smoking and alcohol consumption are not significant aetiological factors in individuals affected by Autosomal dominant optic atrophy

Research paper thumbnail of Ganglion Cell Diseases 48

Research paper thumbnail of Comparing pupil and visual afferent fibre function in dominant optic atrophy

Research paper thumbnail of CORNEAL ENDOTHELIAL-CELL COUNT IN CHILDREN AFTER SURGERY FOR CONGENITAL CATARACT

Research paper thumbnail of Identification of the gene responsible for dominant optic atrophy (OPA1) on chromosome 3q28

Research paper thumbnail of Clinical and molecular genetic findings in autosomal dominant OPA3-related optic neuropathy

neurogenetics, 2014

Leber hereditary optic neuropathy and autosomal dominant optic atrophy are the two most common in... more Leber hereditary optic neuropathy and autosomal dominant optic atrophy are the two most common inherited optic neuropathies. The latter has been associated with mutations in the OPA1 and OPA3 genes. To date, only six families with OPA3-associated dominant optic atrophy have been reported. In order to identify additional families, we performed Sanger sequencing of the OPA3 gene in 75 unrelated optic neuropathy patients. Affected individuals from two families were found to harbour the c.313C > G, p.(Gln105Glu) change in heterozygous state; this genetic defect has been previously reported in four dominant optic atrophy families. Intra- and interfamilial variability in age of onset and presenting symptoms was observed. Although dominant OPA3 mutations are typically associated with optic atrophy and cataracts, the former can be observed in isolation; we report a case with no lens opacities at age 38. Conversely, it is important to consider OPA3-related disease in individuals with bilateral infantile-onset cataracts and to assess optic nerve health in those whose vision fail to improve following lens surgery. The papillomacular bundle is primarily affected and vision is typically worse than 20/40. Notably, we describe one subject who retained normal acuities into the fifth decade of life. The condition can be associated with extraocular clinical features: two affected individuals in the present study had sensorineural hearing loss. The clinical heterogeneity observed in the individuals reported here (all having the same genetic defect in OPA3) suggests that the molecular pathology of the disorder is likely to be complex.

Research paper thumbnail of Retinal changes in a patient with acquired partial lipodystrophy (Laignel-Lavastine and Viard Syndrome)

Acta Ophthalmologica, 2015

Research paper thumbnail of Models of eye disease

Drug Discovery Today: Disease Models, 2013

Blindness and other eye diseases are extraordinarily common. Many of these, mainly in the develop... more Blindness and other eye diseases are extraordinarily common. Many of these, mainly in the developing world, have uncorrected refractive errors which are easily treated, or cataracts which could be cured with a relatively straightforward operation. However, the majority of individuals with eye disease are over 50, and in countries with ageing populations, predominantly in the West, these make up a substantial burden on health care systems. As life expectancy in the developing world Drug Discovery Today: Disease Models

Research paper thumbnail of Perceptions and Understanding of Genetics and Genetic Eye Disease and Attitudes to Genetic Testing and Gene Therapy in a Primary Eye Care Setting

Ophthalmic Genetics, 2015

Genetic eye pathology represents a significant percentage of the causes of blindness in industria... more Genetic eye pathology represents a significant percentage of the causes of blindness in industrialized countries. This study explores the level of understanding and perceptions of genetics and inherited eye diseases and the attitudes to genetic testing and gene therapy. The study was conducted in two parts. Participant groups included were: undergraduate students of optometry, primary eye care professionals and members of the general public. A preliminary study aimed to understand perceptions and to explore the level of knowledge about genetics in general, eye genetics and gene therapy. A second survey was designed to explore attitudes to genetic testing and gene therapy. The majority of participants (82%) perceived genetics as an important science. However, none of them showed a high level of understanding of genetics and inherited eye diseases. Undergraduate students and primary eye care professionals were better informed about inherited eye diseases than the general public (p = 0.001). The majority (80%) across all three groups had a positive attitude to genetic testing and gene therapy. There was a lack of knowledge about the genetic services available among all groups of participants. This calls for serious thinking about the level of dissemination of information about genetics and inherited eye diseases. It shows a broadly supportive attitude to genomic medicine among the public. Improving public awareness and education in inherited eye diseases can improve the utility of genetic testing and therapy.

Research paper thumbnail of Ganglion Cell Diseases

Inherited Chorioretinal Dystrophies, 2014

Research paper thumbnail of The Sight Loss and Vision Priority Setting Partnership (SLV-PSP): overview and results of the research prioritisation survey process

BMJ open, 2014

The Sight Loss and Vision Priority Setting Partnership aimed to identify research priorities rela... more The Sight Loss and Vision Priority Setting Partnership aimed to identify research priorities relating to sight loss and vision through consultation with patients, carers and clinicians. These priorities can be used to inform funding bodies' decisions and enhance the case for additional research funding. Prospective survey with support from the James Lind Alliance. UK-wide National Health Service (NHS) and non-NHS. Patients, carers and eye health professionals. Academic researchers were excluded solely from the prioritisation process. The survey was disseminated by patient groups, professional bodies, at conferences and through the media, and was available for completion online, by phone, by post and by alternative formats (Braille and audio). People were asked to submit the questions about prevention, diagnosis and treatment of sight loss and eye conditions that they most wanted to see answered by research. Returned survey questions were reviewed by a data assessment group. Prio...

Research paper thumbnail of Electrophysiological findings in dominant optic atrophy (DOA) linking to the OPA1 locus on chromosome 3q 28-qter

Documenta ophthalmologica. Advances in ophthalmology

Pattern and flash visual evoked cortical potentials (PVEP, FVEP), and pattern electroretinograms,... more Pattern and flash visual evoked cortical potentials (PVEP, FVEP), and pattern electroretinograms, (PERG) were recorded in 13 affected individuals from 8 families with DOA. These were selected as representative from 87 affected members of 21 pedigrees with DOA who were examined, and who underwent genetic linkage analysis. Linkage to the OPA1 locus on chromosome 3q 28-qter was demonstrated in all families. VA ranged from 6/9 to HM: visual fields showed a variable centro-caecal defect; SLO (when performed) showed diffuse nerve fibre loss; MRI (when performed) showed small intra-orbital optic nerves. In 9/13 patients the PVEP was absent in one or both eyes. Most recordable PVEPs were of abnormal latency, but the delays were not marked (peak times 116-135 msec); amplitudes were low or subnormal. PERG fell within the normal range in 9 eyes of 7 patients. 14 eyes showed an abnormal N95:P50 ratio in keeping with ganglion cell dysfunction. Some severely affected eyes showed P50 component inv...

Research paper thumbnail of Mouse models of dominant optic atrophy: What do they tell us about the pathophysiology of visual loss?

Vision Research, 2011

Dominant optic atrophy (DOA) is the most common inherited optic neuropathy affecting one in every... more Dominant optic atrophy (DOA) is the most common inherited optic neuropathy affecting one in every 12,000 people. It presents with bilateral visual loss, central visual fields defects, colour vision disturbance and optic disc pallor. OPA1 has been identified as the responsible gene and its locus mapped to chromosome 3q28-q29. Mutations in this gene are responsible for the clinical phenotype in over 70% of patients with DOA. Histopathological studies in tissues from patients reveal loss of retinal ganglion cells but the paucity of viable human tissue has raised the importance of an animal model to study the pathophysiology of the disease. In the last decade considerable work has gone into the generation of animal, most notably mouse, models of Opa1 DOA. Two murine models of DOA have been published, designated B6;C3-Opa1 Q285STOP and B6;C3-Opa1 329-355del and they provide valuable insights with respect to neurological and visual phenotyping, mitochondrial dysfunction, optic nerve and axonal changes, retinal ganglion cell depletion and dendritic atrophy. Here we summarise the current state of knowledge of the mechanisms of disease based on data from these models of Opa1 DOA.

Research paper thumbnail of O02 Dysregulated mitophagy and mitochondrial transport in severe dominant optic atrophy due to OPA1 mutations

Neuromuscular Disorders, 2012

Research paper thumbnail of Retinal ganglion cell dendritic degeneration in a mouse model of Alzheimer's disease

Neurobiology of Aging, 2013

Retinal ganglion cells (RGCs) may be regarded as a target biomarker in Alzheimer&... more Retinal ganglion cells (RGCs) may be regarded as a target biomarker in Alzheimer's disease (AD). We therefore explored the possibility that RGC degeneration, rather than cell loss, is an early marker of neuronal degeneration in a murine model of AD. RGC dendritic morphology and dendritic spine densities of CA1 hippocampal pyramidal neurons were quantified in 14-month-old transgenic mice expressing the APP(SWE) (amyloid precusor protein-Swedish mutation) mutation (Tg2576). The dendritic integrity of RGCs was found to be significantly reduced in the absence of significant RGC loss in Tg2576 mice compared with age-matched wild-type controls. In hippocampal CA1 pyramidal neurons, we observed dendritic spines to be present at a lower frequency from the same animals, but this did not reach significance. Synaptic and mitochondrial protein expression markers (PSD95 [postsynaptic density protein 95], synaptophysin, and Mfn2 [mitofusin 2]) showed no significant changes in RGC synaptic densities but a highly significant change in mitochondrial morphology with a marked reduction in the integrity of the mitochondrial cristae. Our findings suggest that, in a well-characterized mouse model of AD, RGC dendritic atrophy precedes cell loss, and this change may be because of accumulations of amyloid-β. Because RGC dendrites are confined to the inner plexiform layer of the retina, imaging techniques that focus on this layer, rather than the loss of RGCs, may provide a sensitive biomarker for monitoring neural damage in AD.

Research paper thumbnail of Guidelines for the use and interpretation of assays for monitoring autophagy

Autophagy, 2012

In 2008 we published the first set of guidelines for standardizing research in autophagy. Since t... more In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.

Research paper thumbnail of Inherited dominant optic neuropathy: from clinical studies to gene function and back again

Drug Discovery Today: Disease Models, 2013

Here we review how clinically driven research into the basic cellular function of the major deter... more Here we review how clinically driven research into the basic cellular function of the major determinant in autosomal dominant optic atrophy, Kjer's type (OPA1), has in turn, facilitated and inspired potential therapeutic endeavours in murine models. Dominant optic atrophy is one of the most frequent causes of inherited optic neuropathy and affects up to 1 in 35 000. Its underlying pathophysiology gives us a remarkable insight into mitochondrial function and how this impacts on neuronal cell survival in the retina.

Research paper thumbnail of Linkage analysis in english pedigrees with dominant optic atrophy

Vision Research, 1995

Abstract: PURPOSETo establish linkage for families with autosomal dominant optic atrophy and to d... more Abstract: PURPOSETo establish linkage for families with autosomal dominant optic atrophy and to determine whether there is any evidence for genetic heterogeneity. METHODSAfter examination patients were entered into the study if they fulfilled the criteria for autosomal dominant optic atrophy of onset in the first decade, blue-yellow dyschromatopsia and characteristic optic nerve pallor. RESULTSGenethon Microsatelite markers as described by Gyapay et al 1994 were used to map the region 3q-28-qter which has been linked to ...

Research paper thumbnail of Visual dysfunction and pupillary responses are dissociated in the Opa3 mutant mouse with retinal degeneration

Acta Ophthalmologica, 2014

ABSTRACT Purpose To assess the affect of the missense mutation p.L122P in a mouse model of 3-meth... more ABSTRACT Purpose To assess the affect of the missense mutation p.L122P in a mouse model of 3-methylglutaconic aciduria (MGA-III), a neuro-metabolic syndrome which presents with retinal and optic atrophy and neurological impairment.Methods Visual acuity was quantified in an optokinetic nystagmus drum by increasing the spatial frequency of the grating until an optomotor response could not be elicited. Pupillary light responsiveness was assessed by video pupillometry. Time course and phenotype of retinal degeneration was examined using haematoxylin and eosin and terminal dUTP transferase nick end labelling.Results Opa3+/+ and Opa3+/- mice showed normal visual acuity by tracking a 2° grating. However, Opa3-/- mice displayed no optomotor response at any grating frequency. Despite this, their pupil response was little affected. Pupil response/intensity curves of Opa3-/- and Opa3+/+ mice diverged somewhat at lower intensities although they only differed significantly at two irradiance levels. At 50% constriction Opa3-/- mice were only 0.61 log units less sensitive than wildtypes. Histology showed panretinal degeneration in adult Opa3-/- mice and TUNEL revealed increased cell death in postnatal and adult Opa3-/- retinae.Conclusion The Opa3-/- mouse is a useful model of the human disease. Retinal atrophy in Opa3-/- animals is associated with widespread retinal thinning. However, dissociation between visual perception and pupillary function implies that the intrinsically photosensitive retinal ganglion cells (ipRGCs) subserving pupillary function may be less susceptible to damage by mutations of Opa3 than the retinogeniculate fibres underlying visual perception.

Research paper thumbnail of A review of primary hereditary optic neuropathies

Journal of inherited metabolic disease, 2003

The primary inherited optic neuropathies are a heterogeneous group of disorders that result in lo... more The primary inherited optic neuropathies are a heterogeneous group of disorders that result in loss of retinal ganglion cells, leading to the clinical appearance of optic atrophy. They affect between 1:10,000 to 1:50,000 people. The main clinical features are a reduction in visual acuity, colour vision abnormalities, centro-caecal visual field defects and pallor of the optic nerve head. Electrophysiological testing shows a normal flash electroretinogram, absent or delayed pattern visually evoked potentials suggestive of a conduction deficit and N95 waveform reduction on the pattern electroretinogram, consistent with a primary ganglion cell pathology. The primary inherited optic neuropathies may be sporadic or familial. The mode of inheritance may be autosomal dominant, autosomal recessive, X-linked recessive or mitochondrial. Within each of these groups, the phenotypic characteristics vary in such features as the mode and age of onset, the severity of the visual loss, the colour def...

Research paper thumbnail of Smoking and alcohol consumption are not significant aetiological factors in individuals affected by Autosomal dominant optic atrophy

Research paper thumbnail of Ganglion Cell Diseases 48

Research paper thumbnail of Comparing pupil and visual afferent fibre function in dominant optic atrophy

Research paper thumbnail of CORNEAL ENDOTHELIAL-CELL COUNT IN CHILDREN AFTER SURGERY FOR CONGENITAL CATARACT

Research paper thumbnail of Identification of the gene responsible for dominant optic atrophy (OPA1) on chromosome 3q28

Research paper thumbnail of Clinical and molecular genetic findings in autosomal dominant OPA3-related optic neuropathy

neurogenetics, 2014

Leber hereditary optic neuropathy and autosomal dominant optic atrophy are the two most common in... more Leber hereditary optic neuropathy and autosomal dominant optic atrophy are the two most common inherited optic neuropathies. The latter has been associated with mutations in the OPA1 and OPA3 genes. To date, only six families with OPA3-associated dominant optic atrophy have been reported. In order to identify additional families, we performed Sanger sequencing of the OPA3 gene in 75 unrelated optic neuropathy patients. Affected individuals from two families were found to harbour the c.313C > G, p.(Gln105Glu) change in heterozygous state; this genetic defect has been previously reported in four dominant optic atrophy families. Intra- and interfamilial variability in age of onset and presenting symptoms was observed. Although dominant OPA3 mutations are typically associated with optic atrophy and cataracts, the former can be observed in isolation; we report a case with no lens opacities at age 38. Conversely, it is important to consider OPA3-related disease in individuals with bilateral infantile-onset cataracts and to assess optic nerve health in those whose vision fail to improve following lens surgery. The papillomacular bundle is primarily affected and vision is typically worse than 20/40. Notably, we describe one subject who retained normal acuities into the fifth decade of life. The condition can be associated with extraocular clinical features: two affected individuals in the present study had sensorineural hearing loss. The clinical heterogeneity observed in the individuals reported here (all having the same genetic defect in OPA3) suggests that the molecular pathology of the disorder is likely to be complex.

Research paper thumbnail of Retinal changes in a patient with acquired partial lipodystrophy (Laignel-Lavastine and Viard Syndrome)

Acta Ophthalmologica, 2015

Research paper thumbnail of Models of eye disease

Drug Discovery Today: Disease Models, 2013

Blindness and other eye diseases are extraordinarily common. Many of these, mainly in the develop... more Blindness and other eye diseases are extraordinarily common. Many of these, mainly in the developing world, have uncorrected refractive errors which are easily treated, or cataracts which could be cured with a relatively straightforward operation. However, the majority of individuals with eye disease are over 50, and in countries with ageing populations, predominantly in the West, these make up a substantial burden on health care systems. As life expectancy in the developing world Drug Discovery Today: Disease Models

Research paper thumbnail of Perceptions and Understanding of Genetics and Genetic Eye Disease and Attitudes to Genetic Testing and Gene Therapy in a Primary Eye Care Setting

Ophthalmic Genetics, 2015

Genetic eye pathology represents a significant percentage of the causes of blindness in industria... more Genetic eye pathology represents a significant percentage of the causes of blindness in industrialized countries. This study explores the level of understanding and perceptions of genetics and inherited eye diseases and the attitudes to genetic testing and gene therapy. The study was conducted in two parts. Participant groups included were: undergraduate students of optometry, primary eye care professionals and members of the general public. A preliminary study aimed to understand perceptions and to explore the level of knowledge about genetics in general, eye genetics and gene therapy. A second survey was designed to explore attitudes to genetic testing and gene therapy. The majority of participants (82%) perceived genetics as an important science. However, none of them showed a high level of understanding of genetics and inherited eye diseases. Undergraduate students and primary eye care professionals were better informed about inherited eye diseases than the general public (p = 0.001). The majority (80%) across all three groups had a positive attitude to genetic testing and gene therapy. There was a lack of knowledge about the genetic services available among all groups of participants. This calls for serious thinking about the level of dissemination of information about genetics and inherited eye diseases. It shows a broadly supportive attitude to genomic medicine among the public. Improving public awareness and education in inherited eye diseases can improve the utility of genetic testing and therapy.

Research paper thumbnail of Ganglion Cell Diseases

Inherited Chorioretinal Dystrophies, 2014

Research paper thumbnail of The Sight Loss and Vision Priority Setting Partnership (SLV-PSP): overview and results of the research prioritisation survey process

BMJ open, 2014

The Sight Loss and Vision Priority Setting Partnership aimed to identify research priorities rela... more The Sight Loss and Vision Priority Setting Partnership aimed to identify research priorities relating to sight loss and vision through consultation with patients, carers and clinicians. These priorities can be used to inform funding bodies' decisions and enhance the case for additional research funding. Prospective survey with support from the James Lind Alliance. UK-wide National Health Service (NHS) and non-NHS. Patients, carers and eye health professionals. Academic researchers were excluded solely from the prioritisation process. The survey was disseminated by patient groups, professional bodies, at conferences and through the media, and was available for completion online, by phone, by post and by alternative formats (Braille and audio). People were asked to submit the questions about prevention, diagnosis and treatment of sight loss and eye conditions that they most wanted to see answered by research. Returned survey questions were reviewed by a data assessment group. Prio...

Research paper thumbnail of Electrophysiological findings in dominant optic atrophy (DOA) linking to the OPA1 locus on chromosome 3q 28-qter

Documenta ophthalmologica. Advances in ophthalmology

Pattern and flash visual evoked cortical potentials (PVEP, FVEP), and pattern electroretinograms,... more Pattern and flash visual evoked cortical potentials (PVEP, FVEP), and pattern electroretinograms, (PERG) were recorded in 13 affected individuals from 8 families with DOA. These were selected as representative from 87 affected members of 21 pedigrees with DOA who were examined, and who underwent genetic linkage analysis. Linkage to the OPA1 locus on chromosome 3q 28-qter was demonstrated in all families. VA ranged from 6/9 to HM: visual fields showed a variable centro-caecal defect; SLO (when performed) showed diffuse nerve fibre loss; MRI (when performed) showed small intra-orbital optic nerves. In 9/13 patients the PVEP was absent in one or both eyes. Most recordable PVEPs were of abnormal latency, but the delays were not marked (peak times 116-135 msec); amplitudes were low or subnormal. PERG fell within the normal range in 9 eyes of 7 patients. 14 eyes showed an abnormal N95:P50 ratio in keeping with ganglion cell dysfunction. Some severely affected eyes showed P50 component inv...

Research paper thumbnail of Mouse models of dominant optic atrophy: What do they tell us about the pathophysiology of visual loss?

Vision Research, 2011

Dominant optic atrophy (DOA) is the most common inherited optic neuropathy affecting one in every... more Dominant optic atrophy (DOA) is the most common inherited optic neuropathy affecting one in every 12,000 people. It presents with bilateral visual loss, central visual fields defects, colour vision disturbance and optic disc pallor. OPA1 has been identified as the responsible gene and its locus mapped to chromosome 3q28-q29. Mutations in this gene are responsible for the clinical phenotype in over 70% of patients with DOA. Histopathological studies in tissues from patients reveal loss of retinal ganglion cells but the paucity of viable human tissue has raised the importance of an animal model to study the pathophysiology of the disease. In the last decade considerable work has gone into the generation of animal, most notably mouse, models of Opa1 DOA. Two murine models of DOA have been published, designated B6;C3-Opa1 Q285STOP and B6;C3-Opa1 329-355del and they provide valuable insights with respect to neurological and visual phenotyping, mitochondrial dysfunction, optic nerve and axonal changes, retinal ganglion cell depletion and dendritic atrophy. Here we summarise the current state of knowledge of the mechanisms of disease based on data from these models of Opa1 DOA.

Research paper thumbnail of O02 Dysregulated mitophagy and mitochondrial transport in severe dominant optic atrophy due to OPA1 mutations

Neuromuscular Disorders, 2012

Research paper thumbnail of Retinal ganglion cell dendritic degeneration in a mouse model of Alzheimer's disease

Neurobiology of Aging, 2013

Retinal ganglion cells (RGCs) may be regarded as a target biomarker in Alzheimer&... more Retinal ganglion cells (RGCs) may be regarded as a target biomarker in Alzheimer's disease (AD). We therefore explored the possibility that RGC degeneration, rather than cell loss, is an early marker of neuronal degeneration in a murine model of AD. RGC dendritic morphology and dendritic spine densities of CA1 hippocampal pyramidal neurons were quantified in 14-month-old transgenic mice expressing the APP(SWE) (amyloid precusor protein-Swedish mutation) mutation (Tg2576). The dendritic integrity of RGCs was found to be significantly reduced in the absence of significant RGC loss in Tg2576 mice compared with age-matched wild-type controls. In hippocampal CA1 pyramidal neurons, we observed dendritic spines to be present at a lower frequency from the same animals, but this did not reach significance. Synaptic and mitochondrial protein expression markers (PSD95 [postsynaptic density protein 95], synaptophysin, and Mfn2 [mitofusin 2]) showed no significant changes in RGC synaptic densities but a highly significant change in mitochondrial morphology with a marked reduction in the integrity of the mitochondrial cristae. Our findings suggest that, in a well-characterized mouse model of AD, RGC dendritic atrophy precedes cell loss, and this change may be because of accumulations of amyloid-β. Because RGC dendrites are confined to the inner plexiform layer of the retina, imaging techniques that focus on this layer, rather than the loss of RGCs, may provide a sensitive biomarker for monitoring neural damage in AD.