1,720,975 research outputs found
Comparison of the handheld RETeval ERG system with a routine ERG system in healthy adults and in paediatric patients
No full textBackground: Electroretinograms (ERG) are necessary for the evaluation of retinal function, however testing children is challenging and only performed at a few specialised centres. The handheld RETeval ERG instrument could prove a valuable tool for clinicians in assessing retinal function. This study evaluates this device using an ISCEV approved modified paediatric protocol and compares it to standard methods using a photic stimulator. Subjects and Method: Cone and rod ERGs were recorded using a standard photic stimulator (Grass) and the RETeval device. Both methods involve using skin electrodes, without mydriasis and under dark and light conditions. Two groups of participants were recruited: 44 healthy adult subjects (mean age =39 years) and 37 paediatric patients (mean=5 years). Three of the paediatric patients were not sufficiently compliant to undertake the RETeval recording.Results: Adult ERG reference range data is presented for the RETeval and compared to the standard system. There is lack of absolute agreement in the measurements between the two devices, highlighting the need for device-specific reference data. In the paediatric group there is a high level of diagnostic agreement between both systems (Cohen’s Kappa k = 0.80). The relative sensitivity and specificity of the RETeval was 1.0 and 0.91. Qualitative patient and user feedback is discussed. Conclusions: ERGs are similar between the two methodologies. This study demonstrates that the RETeval device is a useful tool for assessing retinal function in children. Importantly, it is quick, relatively easy to use and can potentially reduce the burden and costs of paediatric electrodiagnostic assessments. A Correction was issued to figure 1 of this paper shortly after publication due to typographical error. The correction can be accessed at the original paper, the additional links on this record and the correction pdf. Pease use figure 1 in the correction not the Accepted Manuscript
A rare case of CLN3-associated Iiolated retinal degeneration with macular oedema
No full textIntroduction: the neuronal ceroid lipofuscinoses (NCLs) comprise a set of hereditary neurodegenerative disorders involving lysosomal storage, and up to this point, they have been linked to 13 genes. Prevalence is one in every 100,000 live births [1]. Historically, the ailment was categorised into various types based on the onset of the disease. Given considerable variations in disease onset and progression, a conclusive diagnosis often necessitates genetic testing and confirmation of the specific sequence variant responsible. As a result, a novel gene-centred nomenclature has been implemented to simplify the classification of the disease. The classic CLN3 disease, characterized by an early onset in adolescence, previously termed "juvenile neuronal ceroid lipofuscinosis" (JNCL) and commonly known as "Batten disease," is a variant of NCL caused by sequence variations in the CLN3 gene (Ceroid Lipofuscinosis, Neuronal, 3; Online Mendelian Inheritance in Man: 204200). This gene is responsible for encoding a transmembrane protein with an unidentified function [2]. The prevalent sequence variant in CLN3 is a homozygous 1 kb deletion, constituting around 85% of JNCL cases [3]. This deletion spans exons 7 to 8, leading to the production of a truncated and non-functional protein. However, other mutations in CLN3 may give rise to an isolated adult-onset retinal degeneration [4]. Confirmation of a JNCL diagnosis may involve the identification of vacuolated lymphocytes and lysosomal (fingerprint) inclusions on a blood film, in addition to molecular genetic testing [2, 5]. Symptoms commonly manifest in early childhood, including vision loss between 4 and 10 years, behavioural and cognitive issues between 7 and 10 years, and progressive motor deterioration and seizures between 10 and 13 years. Ultimately, these complications lead to premature death in the second or third decade of life [6, 7]. This case illustrates that CLN3 mutations can manifest as an isolated retinal phenotype with cystoid macular oedema, and should be considered in atypical cases of this condition
Use of a handheld electrophysiology device (RETeval, LKC) to identify visual pathway decussation defects
No full textElectrodiagnostic testing (EDTs) require large equipment and trained clinical scientists so are restricted to specialist centres, and often have long waiting lists. Pattern and flash visual evoked potentials (fVEP) have been utilised in the assessment of visual pathway integrity, including chiasmal anomalies in albinism. In this qualitative clinical study, we assess the potential of the handheld RETeval to screen for excess nerve decussation and other post-chiasmal defects
Use of a handheld electrophysiology device (RETeval, LKC) to identify visual pathway decussation defects
No full textPurpose : electrodiagnostic testing (EDTs) require large equipment and trained clinical scientists so are restricted to specialist centres, and often have long waiting lists. Pattern and flash visual evoked potentials (fVEP) have been utilised in the assessment of visual pathway integrity, including chiasmal anomalies in albinism. In this qualitative clinical study, we assess the potential of the handheld RETeval to screen for excess nerve decussation and other post-chiasmal defects.Methods : 18 patients with suspected albinism or retro-chiasmal lesions (aged 0-15yrs, mean 5) were selected from those undergoing routine EDTs at a regional referral centre. Standard paediatric EDTs were performed, followed by fVEP using the RETeval. Control data was collected from 12 volunteers (aged 26-54yrs, mean 32). Right and left occipital electrodes were placed midway between Oz (10-20 system) and either ear. The ground electrode was placed at Fz. FVEPs of 3cd.s/m2 were recorded from 10 brief (<5ms) 1Hz flashes. The left occipital VEP waveform was subtracted from that of the right occiput, creating a single channel response for each eye separately. RETeval data was compared to results obtained from the standard paediatric protocol using a photic stimulator (Grass PS 22). Pearson’s correlation was used to calculate the extent of asymmetry, where a value of -1 showed complete asymmetry whilst a value of +1 showed absolute symmetry in occipital VEP distribution. Data between controls and patients were compared using a Mann-Whitney U test.Results : FVEP testing using both the standard protocol and the RETeval identified asymmetry in 11 patients with suspected albinism. The Pearsons correlate of the albinism cohort (-0.504 ± 0.208) was compared to the control data (0.184 ± 0.339) and a Mann-Whitney U test showed a significant difference between the two groups (p<0.001). This demonstrates the effectiveness of the RETeval in detecting crossed asymmetry secondary to excessive nerve decussation in albinism. The RETeval also detected 7 cases of left and right retro-chiasmal lesions that showed an uncrossed asymmetry.Conclusions : this study adds to the growing body of work investigating the use of the handheld RETeval device for prioritising patients waiting for in-depth EDTs. This data shows the RETeval has the potential to be used as a screening tool for the detection of chiasmal and retro-chiasmal anomalies.<br/
Retinitis pigmentosa and bilateral cystoid macular oedema in a patient heterozygous for the RIM1 mutation previously associated with cone-rod dystrophy 7
No full textThis is the first reported case of bilateral CMO in association with the RIM1 mutation. Overall, our findings were more consistent with a phenotype of retinitis pigmentosa. This could imply that the RIM1 mutation causes diverse retinal dystrophies, or that the previously described CORD7 phenotype resulted from a different variant on the same haplotyp
Eyetracking-enhanced VEP for nystagmus
No full textVisual evoked potential (VEP) testing is an essential first stage in the diagnostic workup of patients with infantile nystagmus (IN). VEPs are an important factor in the diagnosis of albinism, which accompanies IN in ~28% of cases, as well as chiasmal, optic nerve and neurometabolic disease that can all present with IN. VEPs are also used to assess prognostic visual ability in cases of retinal dystrophy and optic nerve disease. Despite being used regularly in those with IN, VEP testing requires patients to keep the eyes still; something that people with IN naturally cannot do. Fixation instability during VEP testing is believed to reduce VEP signal amplitude, and as a result, the reliability of VEP may be reduced in one of the patient groups that needs it the most. This study investigates whether VEP signal quality (amplitude) can be improved in people with IN, by triggering acquisition only during the foveating (slow) periods of the nystagmus waveform
Eyetracking-enhanced VEP for nystagmus
No full textVisual evoked potential (VEP) testing is an essential first stage in the diagnostic workup of patients with infantile nystagmus (IN). VEPs are an important factor in the diagnosis of albinism, which accompanies IN in ~28% of cases, as well as chiasmal, optic nerve and neurometabolic disease that can all present with IN. VEPs are also used to assess prognostic visual ability in cases of retinal dystrophy and optic nerve disease. Despite being used regularly in those with IN, VEP testing requires patients to keep the eyes still; something that people with IN naturally cannot do. Fixation instability during VEP testing is believed to reduce VEP signal amplitude, and as a result, the reliability of VEP may be reduced in one of the patient groups that needs it the most. This study investigates whether VEP signal quality (amplitude) can be improved in people with IN, by triggering acquisition only during the foveating (slow) periods of the nystagmus waveform
Eyetracking-enhanced VEP for nystagmus
No full textVisual evoked potential (VEP) testing is an essential first stage in the diagnostic workup of patients with infantile nystagmus (IN). VEPs are an important factor in the diagnosis of albinism, which accompanies IN in ~28% of cases, as well as chiasmal, optic nerve and neurometabolic disease that can all present with IN. VEPs are also used to assess prognostic visual ability in cases of retinal dystrophy and optic nerve disease. Despite being used regularly in those with IN, VEP testing requires patients to keep the eyes still; something that people with IN naturally cannot do. Fixation instability during VEP testing is believed to reduce VEP signal amplitude, and as a result, the reliability of VEP may be reduced in one of the patient groups that needs it the most. This study investigates whether VEP signal quality (amplitude) can be improved in people with IN, by triggering acquisition only during the foveating (slow) periods of the nystagmus waveform
Long term follow-up of a family with GUCY2D dominant cone dystrophy
No full textThe aim of this manuscript is to describe long term follow-up in a family with GUC2YD dominant cone dystrophy. OCT scans (Triton/OCT-2000 Topcon Ltd, Tokyo, Japan) and Fundus Autofluorescence (FAF) images (Spectralis Heidelberg Engineering, Heidelberg, Germany) were obtained. Goldmann Visual Field (GVF) testing was utilised to monitor the progression of central field loss. Flash and pattern electroretinograms (ERG) and occipital pattern reversal VEPs (VEP) were recorded in accordance with International Society for Clinical Electrophysiology of Vision (ISCEV) standards. Two members of the same family (father and son) were identified to have the heterozygous R838C mutation in the GUC2YD gene. The father presented at the age of 45 with bilateral bull’s eye maculopathy and temporal disc pallor. Over 13 years of serial follow up visits, the bull’s eye maculopathy progressed gradually into macular atrophy. The cone ERGs and visual evoked potentials (VEP) were significantly degraded suggesting poor macular function. Spectral Domain Optical Coherence Tomography (SD-OCT) scans showed progressive loss and disruption of the ellipsoid layer at the foveal level. Autofluorescence showed a central annular area of hypo-autofluorescence corresponding to macular atrophy and retinal pigment epithelial (RPE) loss with a surrounding ring of hyper-autofluorescence indicating the transitional zone between the abnormal-normal tissue. Goldmann Visual Fields (GVFs) showed enlargement of a central scotoma. His son presented at the age of 16 with bilateral granular RPE changes in both maculae. Electrophysiological testing was initially borderline normal but has gradually deteriorated to show reduced cone ERGs and macula function. SD-OCT demonstrated gradual macular thinning and atrophy bilaterally. Unlike his father, there was no disruption of the ellipsoid layer. GVFs showed progression of central visual field loss. In conclusion, both family members with cone dystrophy exhibited gradual changes in their fundi, electrophysiological testing and multimodal imaging. Changes were milder than those observed in other mutations of the same gene
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