Schizophrenia and the retina: Towards a 2020 perspective

Silverstein, Steven M.; Fradkin, Samantha I.; Demmin, Docia

doi:10.1016/j.schres.2019.09.016

Cited by 70 publications

(58 citation statements)

References 161 publications

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“…There and in a later paper (76), he concluded that sensory deafferentationinduced simple hallucinations such as those found in Charles Bonnet syndrome are not a good model for VH in disorders such as schizophrenia where the early visual system is thought to be intact, and VH are thought to involve reduced cholinergic inputs from the basal forebrain and subsequent effects on ventral temporal regions (resulting in complex VH; see paragraph below). However, as we describe in a later section, in the past decade and especially within the past 5 years, there has been consistent reporting of retinal functional and structural impairment in schizophrenia, specifically in the form of reduced strength of retinal neural cell output and thinning of retinal neural layers (28,46,80). In addition, some of the visual distortions reported by people with schizophrenia resemble those seen in cases of retinal disease (18,24,25).…”

Section: Syndromes Of Visual Hallucinationsmentioning

confidence: 61%

The Phenomenology and Neurobiology of Visual Distortions and Hallucinations in Schizophrenia: An Update

Silverstein

Lai

2021

Front. Psychiatry

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Schizophrenia is characterized by visual distortions in ~60% of cases, and visual hallucinations (VH) in ~25–50% of cases, depending on the sample. These symptoms have received relatively little attention in the literature, perhaps due to the higher rate of auditory vs. visual hallucinations in psychotic disorders, which is the reverse of what is found in other neuropsychiatric conditions. Given the clinical significance of these perceptual disturbances, our aim is to help address this gap by updating and expanding upon prior reviews. Specifically, we: (1) present findings on the nature and frequency of VH and distortions in schizophrenia; (2) review proposed syndromes of VH in neuro-ophthalmology and neuropsychiatry, and discuss the extent to which these characterize VH in schizophrenia; (3) review potential cortical mechanisms of VH in schizophrenia; (4) review retinal changes that could contribute to VH in schizophrenia; (5) discuss relationships between findings from laboratory measures of visual processing and VH in schizophrenia; and (6) integrate findings across biological and psychological levels to propose an updated model of VH mechanisms, including how their content is determined, and how they may reflect vulnerabilities in the maintenance of a sense of self. In particular, we emphasize the potential role of alterations at multiple points in the visual pathway, including the retina, the roles of multiple neurotransmitters, and the role of a combination of disinhibited default mode network activity and enhanced state-related apical/contextual drive in determining the onset and content of VH. In short, our goal is to cast a fresh light on the under-studied symptoms of VH and visual distortions in schizophrenia for the purposes of informing future work on mechanisms and the development of targeted therapeutic interventions.

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Section: Syndromes Of Visual Hallucinationsmentioning

confidence: 61%

The Phenomenology and Neurobiology of Visual Distortions and Hallucinations in Schizophrenia: An Update

Silverstein

Lai

2021

Front. Psychiatry

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“…The relatively inexpensive, safe and far‐reaching eye movement technology can mirror cognitive deficits in psychotic patients. Therefore, it is necessary to undertake detailed investigations of visual information processing patterns among psychiatric disorder patients, especially those with SZ spectrum disorder 29, 177, 178 . Recent essential signs of progress, such as the use of integrated eye movement measurements to distinguish patients with SZ from HC, support the statement that the interpretations of one's attention in the form of eye movement measurements should be actively studied in SZ research 1, 42, 47, 54, 62, 98, 179–182 .…”

Section: Cognitive Disturbances As Crucial Features Of Schizophreniamentioning

confidence: 99%

Recent updates of eye movement abnormalities in patients with schizophrenia: A scoping review

Wolf

Ueda

Hirano

2021

Psychiatry Clin Neurosci

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Aim Although eye‐tracking technology expands beyond capturing eye data just for the sole purpose of ensuring participants maintain their gaze at the presented fixation cross, gaze technology remains of less importance in clinical research. Recently, impairments in visual information encoding processes indexed by novel gaze metrics have been frequently reported in patients with schizophrenia. This work undertakes a scoping review of research on saccadic dysfunctions and exploratory eye movement deficits among patients with schizophrenia. It gathers promising pieces of evidence of eye movement abnormalities in attention‐demanding tasks on the schizophrenia spectrum that have mounted in recent years and their outcomes as potential biological markers. Methods The protocol was drafted based on PRISMA for scoping review guidelines. Electronic databases were systematically searched to identify articles published between 2010 and 2020 that examined visual processing in patients with schizophrenia and reported eye movement characteristics as potential biomarkers for this mental illness. Results The use of modern eye‐tracking instrumentation has been reported by numerous neuroscientific studies to successfully and non‐invasively improve the detection of visual information processing impairments among the screened population at risk of and identified with schizophrenia. Conclusions Eye‐tracking technology has the potential to contribute to the process of early intervention and more apparent separation of the diagnostic entities, being put together by the syndrome‐based approach to the diagnosis of schizophrenia. However, context‐processing paradigms should be conducted and reported in equally accessible publications to build comprehensive models.

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“…A similar result, but at a trend level was found for the relationship between more pronounced a-wave amplitude and less variability in the photopic condition. Interestingly, these correlations were not observed in the control group, which suggests that previous findings indicating reduced a- and b-wave activity in schizophrenia [see ( 13 ) for a review] may reflect a subgroup of individuals with schizophrenia with high retinal response variability. This is further supported by the absence of group-level differences in the strength of the relationship between intra-individual variability and retinal response between individuals with schizophrenia and healthy controls.…”

Section: Discussionmentioning

confidence: 66%

“…Data on retinal structure and function are often considered to be proxies for indices of brain structure and function given that the retina and brain share similar origins during embryonic development, as well as similar cell types (e.g., neurons, glial cells), neurotransmitters, a layered architecture, and bidirectional synaptic connections, but the retina is a more accessible component of the central nervous system than the brain ( 10 ). Flash electroretinography (fERG) studies have shown that, compared to healthy controls, people with schizophrenia display amplitude reductions in the a- and b-wave, which reflect weak photoreceptor and bipolar-Müller cell function, respectively, in both photopic (light-adapted) and scotopic (dark-adapted) conditions [see ( 11 – 13 ) for reviews]. To date, however, all fERG studies in schizophrenia have focused on mean between-group differences in ERG indices, and so the degree of intra-individual variability in retinal responses, and how this relates to amplitude reductions, is unknown.…”

Section: Introductionmentioning

confidence: 99%

Absence of Excess Intra-Individual Variability in Retinal Function in People With Schizophrenia

et al. 2020

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People with schizophrenia exhibit increased intra-individual variability in both behavioral and neural signatures of cognition. Examination of intra-individual variability may uncover a unique functionally relevant aspect of impairment that is not captured by typical between-group comparisons of mean or median values. We and others have observed that retinal activity measured using electroretinography (ERG) is significantly reduced in people with schizophrenia; however, it is currently unclear whether greater intra-individual variability in the retinal response can also be observed. To investigate this, we examined intra-individual variability from 25 individuals with schizophrenia and 24 healthy controls under two fERG conditions: (1) a light-adapted condition in which schizophrenia patients demonstrated reduced amplitudes; and (2) a dark-adapted condition in which the groups did not differ in amplitudes. Intraclass correlation coefficients (ICC) were generated to measure intra-individual variability for each subject, reflecting the consistency of activation values (in μv) across all sampling points (at a 2 kHz sampling rate) within all trials within a condition. Contrary to our predictions, results indicated that the schizophrenia and healthy control groups did not differ in intra-individual variability in fERG responses in either the light- or dark-adapted conditions. This finding remained consistent when variability was calculated as the standard deviation (SD) and coefficient of variation (CV) of maximum positive and negative microvolt values within the a- and b-wave time windows. This suggests that although elevated variability in schizophrenia may be observed at perceptual and cognitive levels of processing, it is not present in the earliest stages of sensory processing in vision.

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Schizophrenia and the retina: Towards a 2020 perspective

Cited by 70 publications

References 161 publications

The Phenomenology and Neurobiology of Visual Distortions and Hallucinations in Schizophrenia: An Update

The Phenomenology and Neurobiology of Visual Distortions and Hallucinations in Schizophrenia: An Update

Recent updates of eye movement abnormalities in patients with schizophrenia: A scoping review

Absence of Excess Intra-Individual Variability in Retinal Function in People With Schizophrenia

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