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Eye (London, England) Jul 2023Cerebral Visual Impairment (CVI) is a common condition in the UK. Patients with conditions associated with CVI are frequently seen in paediatric ophthalmology clinics... (Review)
Review
Cerebral Visual Impairment (CVI) is a common condition in the UK. Patients with conditions associated with CVI are frequently seen in paediatric ophthalmology clinics offering eye care professionals an opportunity to identify children proactively. In most cases CVI occurs as part of a neurodevelopmental condition or as a feature of multiple and complex disabilities. However, CVI can also be seen in children with apparently typical development. In some cases, high contrast visual acuity is normal and in other cases severely impaired. As such, identification of CVI requires evaluation of aspects of visual performance beyond high contrast acuity and consideration that visual function of those with CVI may fluctuate. Few paediatric ophthalmologists have received formal training in CVI. The detection and diagnosis of CVI varies across the UK and patients report hugely different experiences. A diagnosis of CVI is made based on professional clinical judgement and it is recognised that individual perspectives and local practice in the specific methodologies of assessment will vary. A systematic review and survey of professionals is underway to attempt to reach agreement on diagnostic criteria. Nonetheless, established pathways and published protocols can offer guidance on how a paediatric ophthalmology service can approach assessment of the child with suspected CVI. The purpose of this paper is to present a summary of research and clinical practice methods for detecting and diagnosing CVI in a paediatric ophthalmology outpatient setting. It represents current understanding of the topic and acknowledges the evolving nature of both practice and the evidence-base. A rapid literature review was undertaken to identify articles relating to clinical investigation of children with CVI. A focus group of QTVI and subject matter experts from sight loss charities was undertaken to address areas which were not covered by the literature review.
Topics: Child; Humans; Consensus; Vision Disorders; Visual Acuity; Ophthalmology; Blindness
PubMed: 36258009
DOI: 10.1038/s41433-022-02261-6 -
Frontiers in Systems Neuroscience 2022Although neural plasticity is now widely studied, there was a time when the idea of adult plasticity was antithetical to the mainstream. The essential stumbling block...
Although neural plasticity is now widely studied, there was a time when the idea of adult plasticity was antithetical to the mainstream. The essential stumbling block arose from the seminal experiments of Hubel and Wiesel who presented convincing evidence that there existed a critical period for plasticity during development after which the brain lost its ability to change in accordance to shifts in sensory input. Despite the zeitgeist that mature brain is relatively immutable to change, there were a number of examples of adult neural plasticity emerging in the scientific literature. Interestingly, some of the earliest of these studies involved visual plasticity in the adult cat. Even earlier, there were reports of what appeared to be functional reorganization in adult rat somatosensory thalamus after dorsal column lesions, a finding that was confirmed and extended with additional experimentation. To demonstrate that these findings reflected more than a response to central injury, and to gain greater control of the extent of the sensory loss, peripheral nerve injuries were used that eliminated ascending sensory information while leaving central pathways intact. Merzenich, Kaas, and colleagues used peripheral nerve transections to reveal unambiguous reorganization in primate somatosensory cortex. Moreover, these same researchers showed that this plasticity proceeded in no less than two stages, one immediate, and one more protracted. These findings were confirmed and extended to more expansive cortical deprivations, and further extended to the thalamus and brainstem. There then began a series of experiments to reveal the physiological, morphological and neurochemical mechanisms that permitted this plasticity. Ultimately, Mowery and colleagues conducted a series of experiments that carefully tracked the levels of expression of several subunits of glutamate (AMPA and NMDA) and GABA (GABAA and GABAB) receptor complexes in primate somatosensory cortex at several time points after peripheral nerve injury. These receptor subunit mapping experiments revealed that membrane expression levels came to reflect those seen in early phases of critical period development. This suggested that under conditions of prolonged sensory deprivation the adult cells were returning to critical period like plastic states, i.e., developmental recapitulation. Here we outline the heuristics that drive this phenomenon.
PubMed: 36762289
DOI: 10.3389/fnsys.2022.1086680 -
The Laryngoscope May 2021The main aim was to assess the misperception of visual verticality (VV) in patients with peripheral vestibular disorders (PVD) in comparison with healthy controls. As... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
The main aim was to assess the misperception of visual verticality (VV) in patients with peripheral vestibular disorders (PVD) in comparison with healthy controls. As secondary objectives, we checked if vestibular, visual, and somatosensory postural pathways can be affected in patients with PVD as well as the characteristics of PVD that could influence on the VV perception.
METHODS
A systematic review with meta-analysis was carried out. The bibliographic search was performed in January, 2020 in PubMed, Scopus, Web of Science (WOS), CINAHL, SciELO. Two reviewers selected the studies that met the inclusion criteria, extracted data, and assessed the methodological quality using the Newcastle-Ottawa Scale (NOS). The VV perception was assessed in two meta-analysis according the used test: The Subjective Visual Vertical test (SVV) or the Rod and Frame Test (RFT) in comparison with healthy subjects. The Standardized Mean Difference (SMD) and its 95% Confidence Interval (95% CI) was used to estimate the pooled effect. Publication bias was assessed using the Egger's test and Trim and Fill Method.
RESULTS
Thirty-four studies were included reporting 3,524 participants. PVD patients showed a misperception of the VV with SVV (SMD = 1.510; 95%CI: 1.190-1.830) and the RFT (SMD = 0.816; 95% CI: 0.234-1.398) respect healthy controls. A subgroup of patients in the acute phase (SMD = 2.5; 95%CI: 2.022-2.978) and who underwent a vestibular surgery (SMD = 2.241; 95%CI: 1.471-3.011) had the greater misperception of VV.
CONCLUSION
Patients with PVD show an alteration in the perception of VV, being greater in the acute phase and after a vestibular surgery. Laryngoscope, 131:1110-1121, 2021.
Topics: Case-Control Studies; Healthy Volunteers; Humans; Otologic Surgical Procedures; Posture; Vestibular Diseases; Vestibule, Labyrinth; Visual Perception
PubMed: 32965689
DOI: 10.1002/lary.29124 -
The Cochrane Database of Systematic... Apr 2008Amblyopia is reduced visual acuity in one or both eyes in the absence of any demonstrable abnormality of the visual pathway. It is not immediately resolved by the... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Amblyopia is reduced visual acuity in one or both eyes in the absence of any demonstrable abnormality of the visual pathway. It is not immediately resolved by the correction of refractive error. Strabismus develops in approximately 5% to 8% of the general population. The aim of treatment for amblyopia is to obtain the best possible level of vision in the amblyopic eye. Different treatment options were examined within the review.
OBJECTIVES
By reviewing available evidence we wanted to establish the most effective treatment for strabismic amblyopia. In particular this review aimed to examine the impact of conventional occlusion therapy for strabismic amblyopia and analyse the role of partial occlusion and optical penalisation for strabismic amblyopia.
SEARCH STRATEGY
We searched CENTRAL, MEDLINE, EMBASE and LILACS in October 2007. There were no language or date restrictions in the electronic searches for trials.
SELECTION CRITERIA
We included randomised controlled trials (RCTs) for the treatment of strabismic amblyopia including participants of any age.
DATA COLLECTION AND ANALYSIS
Two authors working independently extracted and entered data into Review Manager 4.2 using the double data entry facility to check for errors.
MAIN RESULTS
We included two RCTs. The studies reported mean logMAR visual acuity achieved. Mean difference in visual acuity was calculated. When comparing conventional part-time occlusion (with any necessary glasses), PEDIG 2006 reported this treatment was more beneficial than glasses alone for strabismic amblyopia. Mean difference between groups was -0.18 (statistically significant 95% CI -0.32 to -0.04). Supplementing occlusion therapy with near activities may produce a better visual outcome compared to non-near activities after four weeks of treatment (PEDIG 2005). Mean difference between groups was -0.17 (95% CI -0.53 to 0.19). However, this data is from a pilot study and the full data set will be added to updates of the review when available.
AUTHORS' CONCLUSIONS
Occlusion, whilst wearing necessary refractive correction, appears to be more effective than refractive correction alone in the treatment of strabismic amblyopia. Combining occlusion and refractive correction with near activities may be more effective than occlusion and refractive correction alone. Further study of the role of near activities is necessary before a more definitive conclusion can be made. Results of a full trial are expected within the coming year. No RCTs were found that assessed the role of either partial occlusion or optical penalisation to refractive correction for strabismic amblyopia.
Topics: Amblyopia; Humans; Randomized Controlled Trials as Topic; Sensory Deprivation; Strabismus
PubMed: 18425952
DOI: 10.1002/14651858.CD006461.pub2 -
Research in Developmental Disabilities 2010The current definition of Cerebral Visual Impairment (CVI) includes all visual dysfunctions caused by damage to, or malfunctioning of, the retrochiasmatic visual... (Review)
Review
The current definition of Cerebral Visual Impairment (CVI) includes all visual dysfunctions caused by damage to, or malfunctioning of, the retrochiasmatic visual pathways in the absence of damage to the anterior visual pathways or any major ocular disease. CVI is diagnosed by exclusion and the existence of many different causes and symptoms make it an overall non-categorized group. To date, no discrimination is made within CVI based on types of perceptive visual dysfunctions. The aim of this review was to outline which perceptive visual dysfunctions are to be expected based on a number of etiologies of brain damage and brain development disorders with their onset in the pre-, peri- or postnatal period. For each period two etiologies were chosen as the main characteristic brain damage. For each etiology a main search was performed. The selection of the articles was based on the following criteria: age, etiology, imaging, central pathology and perceptive visual function test. The perceptive visual functions included for this review were object recognition, face recognition, visual memory, orientation, visual spatial perception, motion perception and simultaneous perception. Our search resulted in 11 key articles. A diversity of research history is performed for the selected etiologies and their relation to perceptive visual dysfunctions. Periventricular Leukomalacia (PVL) was most studied, whereas the main tested perceptive visual function was visual spatial perception. As a conclusion, the present status of research in the field of CVI does not allow to correlate between etiology, location and perceptive visual dysfunctions in children with brain damage or a brain development disorder. A limiting factor could be the small number of objective tests performed in children experiencing problems in visual processing. Based on recent insights in central visual information processing, we recommend an alternative approach for the definition of CVI that is based on functional visual processing, rather than anatomical landmarks. This could be of benefit in daily practice to diagnose CVI.
Topics: Blindness, Cortical; Brain Diseases; Child; Humans; Visual Pathways; Visual Perception
PubMed: 20822882
DOI: 10.1016/j.ridd.2010.08.001 -
Nutrients Oct 2022Diabetic retinopathy (DR) is a multifactorial neuro-microvascular disease, whose prevalence ranges from 25% to 60% of subjects affected by diabetes mellitus,... (Review)
Review
Diabetic retinopathy (DR) is a multifactorial neuro-microvascular disease, whose prevalence ranges from 25% to 60% of subjects affected by diabetes mellitus, representing the main cause of legal blindness in adults of industrialized countries. The treatment of advanced stage of DR is based on invasive and expensive therapies, while few strategies are available for the early stage or prevention. The mechanisms underlying DR involve a complex interplay between the detrimental effects of hyperglycemia, dyslipidemia, hypoxia, and oxidative stress, providing several pathways potentially targeted by nutrients and nutraceuticals. In this study, we conducted a systematic review of observational and interventional studies, evaluating the effect of nutrients and/or nutraceuticals on the risk of DR and their potential use for the treatment of patients with DR. The analysis of the 41 included studies (27 observational and 14 interventional studies) suggests a promising preventive role of some nutrients, in particular for vitamins B (i.e., B1 and B12), D, and E. However, further investigations are necessary to clarify the potential clinical application of nutraceuticals in the prevention and treatment of DR.
Topics: Adult; Humans; Diabetic Retinopathy; Dietary Supplements; Hyperglycemia; Vitamin B Complex; Nutrients; Diabetes Mellitus; Observational Studies as Topic
PubMed: 36297113
DOI: 10.3390/nu14204430 -
Seminars in Ophthalmology Aug 2023Immune checkpoint inhibitors are a class of monoclonal antibodies that are used as a mainstay of immunotherapy for multiple solid organ malignancies. With the recent...
INTRODUCTION
Immune checkpoint inhibitors are a class of monoclonal antibodies that are used as a mainstay of immunotherapy for multiple solid organ malignancies. With the recent increase in popularity of these agents, immune-related adverse events including optic neuropathy are becoming more frequently reported. This review aims to explore the association between immune checkpoint inhibitors and optic neuropathy through analysis of incidence, clinical features, investigations, treatment, and patient outcomes.
METHOD
A systematic search of the databases PubMed/MEDLINE, Embase, and CENTRAL was performed from inception to September 2022. Data collection and risk of bias analysis was subsequently conducted in accordance with the PRISMA guidelines.
RESULTS
Eleven articles fulfilled the inclusion criteria. The results showed an increased incidence of optic neuropathy among patients receiving immune checkpoint inhibitor therapy compared to the general population. Presentation with painless reduced visual acuity and optic disc swelling was most common. Investigation findings were poorly documented. The only two patients who achieved full resolution of symptoms were treated with oral prednisolone.
CONCLUSION
There is a strong association between immune checkpoint inhibitor therapy and development of optic neuropathy. Although it remains uncommon, the incidence of optic neuropathy in this population exceeds that of the general population. Future research is needed to further characterise the risk profiles of patients who are most likely to develop ICI-associated optic neuropathy, and treatment pathways for these patients.
Topics: Humans; Immune Checkpoint Inhibitors; Neoplasms; Optic Nerve Diseases; Optic Neuropathy, Ischemic; Antibodies, Monoclonal
PubMed: 36683270
DOI: 10.1080/08820538.2023.2168494 -
Journal of Clinical Neuroscience :... Feb 2015Anterior visual pathway cavernous malformations (CM) are rare diagnoses with poorly-defined natural history and management. A systematic review of all reports of... (Review)
Review
Anterior visual pathway cavernous malformations (CM) are rare diagnoses with poorly-defined natural history and management. A systematic review of all reports of anterior visual pathway CM was performed to identify all English-language articles with histopathologically-proven anterior visual pathway CM published from 1950 to December 2013. Patient demographics, presenting symptoms, CM location, treatment modality and clinical outcome were recorded and analyzed. The case of a 60-year-old woman from our institution with acute-on-chronic visual disturbance secondary to visual pathway CM is presented. Including the current patient, 70 cases of anterior visual pathway CM have been published to our knowledge. The average patient age is 34.8 ± standard deviation of 14.2 years, with a female preponderance (n = 37, 52.9%). The majority of patients had an acute (n = 44; 62.9%; 95% confidence interval [CI] 0.51-0.73) onset of symptoms. In at least 55.6% (n = 40) of patients, the cause of visual disturbance was initially misdiagnosed. The majority (91.4%; n = 64) of patients underwent craniotomy, with complete resection and subtotal resection achieved in 53.1% (n = 34; 95%CI 0.41-0.65) and 17.2% (n = 11; 95%CI 0.10-0.28) of all surgical patients, respectively. Comparing surgically managed patients, complete resection improved visual deficits in 59.0% (n = 20; 95%CI 0.42-0.75), while subtotal resection improved visual deficits in 50.0% (n = 5; 95%CI 0.24-0.76; p = 0.62). CM is an important differential diagnosis for suprasellar lesions presenting with visual disturbance. A high index of suspicion is required in its diagnosis. Expeditious operative management is recommended to improve clinical outcomes.
Topics: Adult; Central Nervous System Neoplasms; Diagnosis, Differential; Female; Hemangioma, Cavernous, Central Nervous System; Humans; Magnetic Resonance Imaging; Male; Middle Aged; Vision Disorders; Visual Pathways
PubMed: 25439746
DOI: 10.1016/j.jocn.2014.07.027 -
Survey of Ophthalmology 2024Among ocular infections, trachoma is the main cause of blindness. Repeated conjunctival Chlamydia trachomatis infections lead to trichiasis, corneal opacification, and... (Review)
Review
Among ocular infections, trachoma is the main cause of blindness. Repeated conjunctival Chlamydia trachomatis infections lead to trichiasis, corneal opacification, and visual impairment. Surgery is often needed to relieve discomfort and preserve vision; however, a high postoperative trachomatous trichiasis (PTT) rate has been observed in various settings. We wanted to know why, whether PTT rates could be reduced, and how to manage the PTT that occurs. We performed a search of the literature. Of 217 papers screened, 59 studies were identified for inclusion as potentially relevant, the majority having been excluded for not directly concerning PTT in humans. Preventing PTT is a major challenge. Only one published trial, the STAR trial in Ethiopia, has reported a cumulative PTT rate <10% one year after surgery. The literature on the management of PTT is sparse. Though no PTT management guidelines are available, high-quality surgery with a low rate of unfavorable outcomes for PTT patients is likely to require enhanced training of a smaller group of highly-skilled surgeons. Based on the surgical complexity and the authors' own experience, the pathway for patients suffering from PTT should be studied further for improvement.
Topics: Humans; Trachoma; Trichiasis; Conjunctiva; Blindness; Vision, Low
PubMed: 36878359
DOI: 10.1016/j.survophthal.2023.02.008 -
Eye (London, England) Jul 2023Corneal and ocular surface diseases (OSDs) carry significant psychosocial and economic burden worldwide. We set out to review the literature on the application of... (Review)
Review
Corneal and ocular surface diseases (OSDs) carry significant psychosocial and economic burden worldwide. We set out to review the literature on the application of artificial intelligence (AI) and bioinformatics for analysis of biofluid biomarkers in corneal and OSDs and evaluate their utility in clinical decision making. MEDLINE, EMBASE, Cochrane and Web of Science were systematically queried for articles using AI or bioinformatics methodology in corneal and OSDs and examining biofluids from inception to August 2021. In total, 10,264 articles were screened, and 23 articles consisting of 1058 individuals were included. Using various AI/bioinformatics tools, changes in certain tear film cytokines that are proinflammatory such as increased expression of apolipoprotein, haptoglobin, annexin 1, S100A8, S100A9, Glutathione S-transferase, and decreased expression of supportive tear film components such as lipocalin-1, prolactin inducible protein, lysozyme C, lactotransferrin, cystatin S, and mammaglobin-b, proline rich protein, were found to be correlated with pathogenesis and/or treatment outcomes of dry eye, keratoconus, meibomian gland dysfunction, and Sjögren's. Overall, most AI/bioinformatics tools were used to classify biofluids into diseases subgroups, distinguish between OSD, identify risk factors, or make predictions about treatment response, and/or prognosis. To conclude, AI models such as artificial neural networks, hierarchical clustering, random forest, etc., in conjunction with proteomic or metabolomic profiling using bioinformatics tools such as Gene Ontology or Kyoto Encylopedia of Genes and Genomes pathway analysis, were found to inform biomarker discovery, distinguish between OSDs, help define subgroups with OSDs and make predictions about treatment response in a clinical setting.
Topics: Humans; Artificial Intelligence; Proteomics; Dry Eye Syndromes; Cornea; Tears
PubMed: 36380089
DOI: 10.1038/s41433-022-02307-9