-
Disability and Rehabilitation Apr 2022To systematically review the evidence for effectiveness of rehabilitation interventions in people who are visually impaired, living in low- and middle-income countries.
OBJECTIVE
To systematically review the evidence for effectiveness of rehabilitation interventions in people who are visually impaired, living in low- and middle-income countries.
METHODS
Fifteen databases and the grey literature were searched up until February 2020; papers were identified according to eligibility criteria, and assessed for risk of bias. Eligible studies were controlled trials (randomised or non-randomised) of rehabilitation interventions for blind or visually impaired adults or children from low- and middle-income countries. Possible outcomes included visual acuity, activities of daily living, safety, quality of life and psychological status.
RESULTS
Fifteen eligible studies were identified from India, Turkey, Nigeria, Croatia and Iran. Six studies were randomised, seven were non-randomised trials, and in two the method of allocation was not clear. Participants were adults, children and both adults and children. Seven studies were small ( ≤ 65) and examined the effect of training programmes. Remaining studies compared the effect of low vision aids, economic rehabilitation, goalball, rehabilitation compliance and service delivery methods, including one large four-arm randomised trial ( = 436). Studies measured a variety of outcomes, and mostly showed a positive effect of interventions for pre- and post-intervention assessment, although between intervention group comparisons were often inconclusive. Overall, only four studies had a low risk of bias.
CONCLUSIONS
A lack of high-quality evidence for rehabilitation interventions is a barrier to provision of low vision services in low- and middle-income countries. Future research should focus on establishing effectiveness and cost-effectiveness of devices and models of vision rehabilitation appropriate for low-resource settings.IMPLICATIONS FOR REHABILITATIONThe systematic review found a lack of high-quality evidence for rehabilitation interventions is a barrier to provision of low vision services in low- and middle-income countries.Consider how visual rehabilitation interventions which have been shown to be effective can be delivered by non-specialists.Ensure that service providers for people who are visually impaired are trained in recognising depression and anxiety and have pathways for referral to mental health services, as appropriate.
Topics: Activities of Daily Living; Adult; Blindness; Child; Developing Countries; Humans; Quality of Life; Vision, Low; Visually Impaired Persons
PubMed: 32726142
DOI: 10.1080/09638288.2020.1794063 -
World Neurosurgery Aug 2022Optic pathway gliomas (OPGs) typically occur in the first decade of life and 40%-50% are not associated with neurofibromatosis 1 (NF1) (sporadic). Management strategies... (Review)
Review
OBJECTIVE
Optic pathway gliomas (OPGs) typically occur in the first decade of life and 40%-50% are not associated with neurofibromatosis 1 (NF1) (sporadic). Management strategies are often patient specific because of the variable and unpredictable course. No study has summarized the effect of treatment strategies on visual outcomes in the subset of pediatric patients with sporadic OPG.
METHODS
We conducted a systematic review to determine the nature of visual outcomes in pediatric patients with sporadic, non-NF1-associated OPG using the PubMed, Embase, Scopus, Cochrane, and CINAHL Plus databases. Visual outcomes were categorized as improved, unchanged, or deteriorated.
RESULTS
Of 1316 results, 31 articles were included. Treatment indications are unknown with full clinical detail. A total of 45.2% (14/31) reported deteriorated outcomes after treatment, 35.5% (11/31) no change, and 19.4% (6/31) improvement. Of radiotherapy studies, 50.0% (4/8) found no change, 37.5% (3/8) deterioration, and 12.5% (1/8) improvement. Of chemotherapy studies, 35.7% (5/14) each showed improvement and deterioration, whereas 28.6% (4/14) showed no change. Of surgical studies, 62.5% (5/8) indicated deterioration, and 37/5% (3/8) indicated no change. The singular study examining observation reported deterioration in visual outcomes. Factors associated with poor visual outcomes included signs and symptoms of visual decline at presentation, involvement of the intraorbital optic nerve, and intracranial hypertension requiring surgery. Causality cannot be determined from systematic review.
CONCLUSIONS
Most studies showed that vision in pediatric patients with sporadic OPG is stable to poor after observation, chemotherapy, radiotherapy, or surgery. Chemotherapy may be associated with most favorable visual outcomes.
Topics: Child; Follow-Up Studies; Humans; Neurofibromatosis 1; Optic Nerve Glioma; Optic Nerve Neoplasms; Retrospective Studies
PubMed: 35430402
DOI: 10.1016/j.wneu.2022.04.033 -
Neurological Sciences : Official... Apr 2022Hemianopia is a complete or partial blindness in the visual fields of both eyes, commonly caused by cerebral infarction. It has been hypothesized that systematic... (Review)
Review
BACKGROUND
Hemianopia is a complete or partial blindness in the visual fields of both eyes, commonly caused by cerebral infarction. It has been hypothesized that systematic audio-visual (AV) stimulation of the blind hemifield can improve accuracy and search times, probably due to the stimulation of bimodal representations in the superior colliculus (SC), an important multisensory structure involved in both the initiation and execution of saccades.
METHODS
A narrative synthesis of the findings is presented to highlight how AV rehabilitation impacts on patients with hemianopia including visual oculomotor function, functional ability in activities of daily living, hemianopic dyslexia, visual scanning and searching tasks, maintaining of functional ability post training and the effect on brain multisensory integration by using neuroimaging.
RESULTS
Sixteen studies were included (fourteen articles (188 participants) and two literature reviews). Results were grouped into AV training of hemianopia in adults and in children and then further grouped according to the AV task type: tasks measuring the training effects by comparing visual stimulation training to audio-visual training, localization abilities in homonymous hemianopia (HH) and AV integration in patients with HH.
CONCLUSION
Systematic AV training may improve the processing of visual information by recruiting subcortical pathways, and because most of the patients with visual cortex damage have an intact SC, it might be useful to use the bimodal AV training to activate retinotectal functions. Nevertheless, the underlying mechanisms supporting the reported positive effects are not currently understood. Systematic functional and/or structural imaging studies may help in understanding the underlying mechanism and inform the design of optimal training paradigms.
Topics: Acoustic Stimulation; Activities of Daily Living; Adult; Child; Hemianopsia; Humans; Photic Stimulation; Stroke; Survivors; Visual Fields
PubMed: 35149925
DOI: 10.1007/s10072-022-05926-y -
Archivos de La Sociedad Espanola de... Jul 2021Eye oscillations, both nystagmic and non-nystagic, can occur from birth. Most correspond to infantile nystagmus that dubates in the first six months of life, which... (Review)
Review
INTRODUCTION
Eye oscillations, both nystagmic and non-nystagic, can occur from birth. Most correspond to infantile nystagmus that dubates in the first six months of life, which include idiopathic, sensory, latent, or overt latent motor nystagmus. Those associated with neurological diseases or syndromes correspond to approximately 33%, their identification and correct evaluation being important given the potential visual and vital complications.
MATERIAL AND METHODS
We made a systematic review of the literature on supranuclear gaze control mechanisms and the main ocular oscillations with possible neurological implications, both in childhood. With this, we intend to assess if there are already established clinical-anatomical associations, and to propose a protocol on the complementary studies to be carried out in these cases.
RESULTS
There are still anatomical pathways involved in supranuclear gaze control that are not fully clarified and understood. Besides, except in the case of nystagmus in seesaw and upbeat, we did not find anatomical explanations for their pathogenesis. The need for complete neuro-ophthalmological physical examinations and the request for additional tests in children who present ocular oscillations with neurological characteristics are clear.
CONCLUSIONS
Supranuclear gaze control follows a complex neurological network that still needs to be studied better. With a better dissection of the same we could try to understand why the ocular oscillations that we studied have these specific forms of presentation. As for the complementary requests, the request for neuroimaging tests is practically constant, making the others according to the specific case before which we find ourselves.
Topics: Child; Eye Movements; Humans; Nystagmus, Pathologic; Physical Examination; Syndrome
PubMed: 34217474
DOI: 10.1016/j.oftale.2020.09.018 -
Progress in Brain Research 2020Visual snow syndrome is a debilitating disorder characterized by tiny flickering dots (like TV static) in the entire visual field and a set of accompanying visual...
BACKGROUND
Visual snow syndrome is a debilitating disorder characterized by tiny flickering dots (like TV static) in the entire visual field and a set of accompanying visual (palinopsia, enhanced entoptic phenomena, photophobia, nyctalopia), nonvisual (e.g. tinnitus) and nonperceptional (e.g. concentration problems, irritability) symptoms. Its pathophysiology is enigmatic and therapy is often frustrating.
OBJECTIVES
To summarize our current understanding of pathophysiology and treatment of visual snow syndrome.
METHODS
A systematic search of PubMed database was performed using the key word "visual snow" and predefined in- and exclusion criteria. The results were stratified into "treatment" and "pathophysiology." Additionally, we conducted a search with the key words "persistent migraine aura" and "persistent visual aura" and screened for mis-diagnosed patients actually fulfilling the criteria for visual snow syndrome. The reference lists of most publications and any other relevant articles known to the authors were also reviewed and added if applicable.
RESULTS
From the 50 original papers found by searching for "visual snow," 21 were included according to the inclusion and exclusion criteria. Additional four publications came searching for "persistent migraine aura" or "persistent visual aura." Further publications derived from literature references resulting in a total of 20 articles for pathophysiology and 15 for treatment with some overlaps. Regarding pathophysiology, hyperexcitability of the visual cortex and a processing problem of higher order visual function are assumed, but the location is still in discussion. In particular, it is unclear if the primary visual cortex, the visual association cortex or the thalamocortical pathway is involved. Regarding treatment, data is available on a total of 153 VSS patients with medication mentioned for 54 resulting in a total of 136 trials. From the 44 different medications tried, only eight were effective at least once. The best data is available for lamotrigine being effective in 8/36 (22.2%, including one total response and no worsening), followed by topiramate being effective in 2/13 (15.4%, no total response and one worsening). The only other medication resulting in worsening of VSS was amitriptyline according to our literature review. The others reported to be effective at least once were valproate, propranolol, verapamil, baclofen, naproxen and sertraline. The nonpharmacological approach using color filters of the yellow-blue color spectrum might also be helpful in some patients.
CONCLUSIONS
Visual snow syndrome is still far from being fully understood. In respect of pathophysiology, a disorder of visual processing is likely. The best pharmacological evidence exists for lamotrigine, which can be discussed off-label. As nonpharmacological option, patients might benefit from tinted glasses for everyday use.
Topics: Humans; Migraine with Aura; Vision Disorders
PubMed: 33008511
DOI: 10.1016/bs.pbr.2020.05.020 -
Brain Imaging and Behavior Dec 2022Our primary objective was to assess consistent activation and deactivation among healthy participants and patients reporting vertigo. Our secondary aim was to evaluate... (Review)
Review
Our primary objective was to assess consistent activation and deactivation among healthy participants and patients reporting vertigo. Our secondary aim was to evaluate the influence of the stimulus and the direction of the perception of self-motion We realized a systematic review with an extensive data visualization. We included neuroimaging studies (e.g., functional magnetic resonance imaging [fMRI], positron emission tomography [PET] or near infrared spectroscopy [NIRS]) that have measured functional activity in human adults reporting vertigo and/or dizziness. We included 21 studies (n = 336 participants), ~ 64% male, age ranging from 18 to 80.5 years. The different stimuli used to induce vertigo: caloric stimulation, galvanic stimulation, visual stimulation or vibratory stimulus on neck muscles. We found a consistent activation of the insular cortex, inferior parietal lobule, putamen, cerebellum, anterior cingulate cortex, precentral gyrus, superior temporal gyrus and thalamus. Cortical and subcortical activation seems to have a contralateral pattern to the perception of self-movement. We found a deactivation pattern of structures related to the ventral and third visual pathway. Vertigo is an unpleasant and subjective experience which involves multiple vestibular and non-specific networks with the involvement of a cortico-basal ganglia- cerebellar-thalamic network.
Topics: Adult; Humans; Male; Adolescent; Young Adult; Middle Aged; Aged; Aged, 80 and over; Female; Magnetic Resonance Imaging; Brain Mapping; Photic Stimulation; Neuroimaging; Vertigo
PubMed: 36242719
DOI: 10.1007/s11682-022-00729-3 -
Neurosurgical Review Apr 2018The objective of this systematic literature review is to assess the role of retinal optical coherence tomography (OCT) in the evaluation of patients with tumors of the... (Review)
Review
The objective of this systematic literature review is to assess the role of retinal optical coherence tomography (OCT) in the evaluation of patients with tumors of the visual pathway. We performed a PubMed database search according to the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The search was restricted to articles published in English between 2000 and 2016, with at least 10 human adult participants enrolled. Twenty-seven articles met the eligibility criteria. All studies investigated tumors of the anterior visual pathway. Both time-domain and spectral-domain OCT technologies were used and the role of OCT as diagnostic and/or prognostic tool was studied. Retinal OCT provides structural information about ganglion cell axon integrity and is complementary to visual function examination. OCT is a prognostic factor for post-operative visual outcome.
Topics: Humans; Nerve Compression Syndromes; Occipital Lobe; Optic Chiasm; Optic Nerve Neoplasms; Postoperative Complications; Retina; Retinal Ganglion Cells; Tomography, Optical Coherence; Visual Cortex; Visual Pathways
PubMed: 27465394
DOI: 10.1007/s10143-016-0772-1 -
Child's Nervous System : ChNS :... Sep 2020Optic pathway gliomas (OPGs), also known as Visual Pathway Gliomas, are insidious, debilitating tumours. They are most commonly WHO grade 1 pilocytic astrocytomas and... (Review)
Review
INTRODUCTION
Optic pathway gliomas (OPGs), also known as Visual Pathway Gliomas, are insidious, debilitating tumours. They are most commonly WHO grade 1 pilocytic astrocytomas and frequently occur in patients with neurofibromatosis type 1. The location of OPGs within the optic pathway typically precludes complete resection or optimal radiation dosing, hence outcomes remain poor compared to many other low-grade gliomas. The aim of this systematic review was to formulate a comprehensive list of all current ongoing clinical trials that are specifically looking at clinical care of OPGs in order to identify trends in current research and provide an overview to guide future research efforts.
METHODS
This systematic review was conducted in line with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. The Cochrane Controlled Register of Trials (CENTRAL) and ClinicalTrials.gov were searched. Inclusion and exclusion criteria were applied and final results were reviewed.
RESULTS
501 clinical trials were identified with the search strategy. All were screened and eligible studies extracted and reviewed. This yielded 36 ongoing clinical trials, 27 of which were pharmacological agents in phase I-III. The remaining trials were a mixture of biological agents, radiation optimisation, diagnostic imaging, surgical intervention, and a social function analysis.
CONCLUSION
OPG is a complex multifaceted disease, and advances in care require ongoing research efforts across a spectrum of different research fields. This review provides an update on the current state of research in OPG and summarises ongoing trials.
Topics: Astrocytoma; Humans; Neurofibromatosis 1; Optic Nerve Glioma
PubMed: 32556546
DOI: 10.1007/s00381-020-04724-1 -
BioMed Research International 2015Glaucoma is a multifactorial disease that is the leading cause of irreversible blindness. Recent data documented that glaucoma is not limited to the retinal ganglion... (Review)
Review
Glaucoma is a multifactorial disease that is the leading cause of irreversible blindness. Recent data documented that glaucoma is not limited to the retinal ganglion cells but that it also extends to the posterior visual pathway. The diagnosis is based on the presence of signs of glaucomatous optic neuropathy and consistent functional visual field alterations. Unfortunately these functional alterations often become evident when a significant amount of the nerve fibers that compose the optic nerve has been irreversibly lost. Advanced morphological and functional magnetic resonance (MR) techniques (morphometry, diffusion tensor imaging, arterial spin labeling, and functional connectivity) may provide a means for observing modifications induced by this fiber loss, within the optic nerve and the visual cortex, in an earlier stage. The aim of this systematic review was to determine if the use of these advanced MR techniques could offer the possibility of diagnosing glaucoma at an earlier stage than that currently possible.
Topics: Diagnostic Techniques, Ophthalmological; Glaucoma; Humans; Magnetic Resonance Imaging
PubMed: 26167474
DOI: 10.1155/2015/160454 -
Aging & Mental Health Oct 2021Visual impairment and cognitive disorders are common among older people in Low-and Middle-Income Countries (LMIC). Several recent studies performed in High-Income...
OBJECTIVES
Visual impairment and cognitive disorders are common among older people in Low-and Middle-Income Countries (LMIC). Several recent studies performed in High-Income Countries suggested that visual impairment is associated with cognitive disorders. However, no synthesis of current knowledge exists for LMIC.
METHODS
We have conducted an extensive literature search combining six databases and two grey literature databases. We searched for studies assessing the link between visual and cognitive impairments carried out in LMIC. The systematic search was performed up to 14th February 2019.
RESULTS
Overall, eight studies were included in this review. Among them, five studies were performed in Asia and seven studies had a cross-sectional design. Mean age of the participants varied from 64.2 to 76.2 years. Participants were most often females. Only three studies were specifically focused on the association between visual impairment and cognitive disorders. Out of the eight studies included, four reported a significant association; two showed a possible association and two did not retrieve any statistically significant effect. Heterogeneity in assessments of visual and cognitive impairments was high.
CONCLUSION
In LMIC, very few studies explored the association between visual and cognitive impairments among older people. The current review seems to suggest that visual impairment is associated with cognitive disorders in LMIC. However, further studies are required to improve the knowledge on this relationship. Improving vision, in particular through optical correction and cataract surgery, could potentially be easy pathways to reduce cognitive disorders incidence and to improve quality of life of people affected by this disorder.
Topics: Aged; Cognition; Cross-Sectional Studies; Developing Countries; Female; Humans; Quality of Life; Vision Disorders
PubMed: 32896159
DOI: 10.1080/13607863.2020.1808878