-
The Lancet. Global Health Feb 2021Many causes of vision impairment can be prevented or treated. With an ageing global population, the demands for eye health services are increasing. We estimated the... (Meta-Analysis)
Meta-Analysis
Causes of blindness and vision impairment in 2020 and trends over 30 years, and prevalence of avoidable blindness in relation to VISION 2020: the Right to Sight: an analysis for the Global Burden of Disease Study.
BACKGROUND
Many causes of vision impairment can be prevented or treated. With an ageing global population, the demands for eye health services are increasing. We estimated the prevalence and relative contribution of avoidable causes of blindness and vision impairment globally from 1990 to 2020. We aimed to compare the results with the World Health Assembly Global Action Plan (WHA GAP) target of a 25% global reduction from 2010 to 2019 in avoidable vision impairment, defined as cataract and undercorrected refractive error.
METHODS
We did a systematic review and meta-analysis of population-based surveys of eye disease from January, 1980, to October, 2018. We fitted hierarchical models to estimate prevalence (with 95% uncertainty intervals [UIs]) of moderate and severe vision impairment (MSVI; presenting visual acuity from <6/18 to 3/60) and blindness (<3/60 or less than 10° visual field around central fixation) by cause, age, region, and year. Because of data sparsity at younger ages, our analysis focused on adults aged 50 years and older.
FINDINGS
Global crude prevalence of avoidable vision impairment and blindness in adults aged 50 years and older did not change between 2010 and 2019 (percentage change -0·2% [95% UI -1·5 to 1·0]; 2019 prevalence 9·58 cases per 1000 people [95% IU 8·51 to 10·8], 2010 prevalence 96·0 cases per 1000 people [86·0 to 107·0]). Age-standardised prevalence of avoidable blindness decreased by -15·4% [-16·8 to -14·3], while avoidable MSVI showed no change (0·5% [-0·8 to 1·6]). However, the number of cases increased for both avoidable blindness (10·8% [8·9 to 12·4]) and MSVI (31·5% [30·0 to 33·1]). The leading global causes of blindness in those aged 50 years and older in 2020 were cataract (15·2 million cases [9% IU 12·7-18·0]), followed by glaucoma (3·6 million cases [2·8-4·4]), undercorrected refractive error (2·3 million cases [1·8-2·8]), age-related macular degeneration (1·8 million cases [1·3-2·4]), and diabetic retinopathy (0·86 million cases [0·59-1·23]). Leading causes of MSVI were undercorrected refractive error (86·1 million cases [74·2-101·0]) and cataract (78·8 million cases [67·2-91·4]).
INTERPRETATION
Results suggest eye care services contributed to the observed reduction of age-standardised rates of avoidable blindness but not of MSVI, and that the target in an ageing global population was not reached.
FUNDING
Brien Holden Vision Institute, Fondation Théa, The Fred Hollows Foundation, Bill & Melinda Gates Foundation, Lions Clubs International Foundation, Sightsavers International, and University of Heidelberg.
Topics: Aged; Aged, 80 and over; Blindness; Cataract; Eye Diseases; Female; Glaucoma; Global Burden of Disease; Global Health; Humans; Macular Degeneration; Male; Middle Aged; Refractive Errors; Vision Disorders; Vision, Low; Visual Acuity
PubMed: 33275949
DOI: 10.1016/S2214-109X(20)30489-7 -
Clinical & Experimental Optometry Sep 2019Smartphone and tablet use in Australia and worldwide is reaching saturation levels and associated visual and ocular discomfort such as headaches, eyestrain, dry eyes and... (Review)
Review
Smartphone and tablet use in Australia and worldwide is reaching saturation levels and associated visual and ocular discomfort such as headaches, eyestrain, dry eyes and sore eyes are widespread. This review synthesises the available literature and considers these symptoms in the context of a binocular vision and/or ocular surface aetiology. Eye discomfort with smartphones and tablets is discussed alongside similar symptoms reported with desktop computer use. Handheld devices differ from computers in viewing position and distance, screen size and luminance, and patterns of use. Accommodation is altered with handheld device use, with increased lag and decreased amplitude. Smartphone and tablet use results in reduced fusional convergence and possibly a receded near point of convergence. This is similar to what happens with computer use. Findings related to blink rate with smartphone and tablet use are contradictory, perhaps due to the influence of task difficulty, and there is limited evidence related to blink amplitude. Reduced blink rate and amplitude are consistently reported with computer use. Use of handheld digital devices, like computers, may adversely impact tear stability. There is insufficient evidence to support the impact of handheld devices on tear volume, although this is reduced with computer use. The available literature does not conclusively link eye and visual discomfort symptoms reported with handheld digital devices, with changes in binocular vision, blinking or ocular surface. However, there is a gap in our understanding of symptoms which occur with smartphone and tablet use in the context of how these devices are used. In addition, studies are required in high users such as teenagers, and in patients with dry eye or accommodative/binocular vision anomalies, all of whom may have a higher risk of symptoms. A better understanding of symptom aetiology can guide clinical advice to minimise adverse impacts on visual and ocular surface health and discomfort.
Topics: Asthenopia; Computers; Computers, Handheld; Dry Eye Syndromes; Humans; Smartphone; Vision Disorders; Vision, Binocular
PubMed: 30663136
DOI: 10.1111/cxo.12851 -
CMAJ : Canadian Medical Association... Mar 2020
Topics: Fluorescein Angiography; Humans; Referral and Consultation; Retinal Detachment; Vision Disorders; Visual Field Tests
PubMed: 32392514
DOI: 10.1503/cmaj.191337 -
Journal of Optometry 2022Convergence insufficiency (CI) is a common binocular vision (BV) disorder characterized by difficulty in maintaining motor fusion at near, which affects approximately... (Review)
Review
Convergence insufficiency (CI) is a common binocular vision (BV) disorder characterized by difficulty in maintaining motor fusion at near, which affects approximately 7.5 percent of the population. Diagnostic criteria for the disorder are inconsistent, ranging from one to many clinical signs. Methodology for clinical tests is inconsistent in measurement technique, visual targets, required repetitions, and normative values. This manuscript demonstrates the inconsistencies amongst published studies, and highlights the importance of consistent clinical diagnostic signs, measurement techniques, visual targets, and cut-off criteria. For each clinical sign, the recommended methodology for the procedure is described. Several studies do not take age into account when diagnosing CI in their cohorts. As such, the review emphasizes changes in diagnostic signs with age. This manuscript highlights the need for consistent and clear procedures and diagnostic criteria amongst clinicians and provides the basis for future studies in terms of diagnostic testing required for CI of varying age groups.
Topics: Accommodation, Ocular; Convergence, Ocular; Humans; Ocular Motility Disorders; Vision Disorders; Vision, Binocular
PubMed: 34963569
DOI: 10.1016/j.optom.2021.11.002 -
Current Opinion in Neurology Feb 2020Visual snow is considered a disorder of central visual processing resulting in a perturbed perception of constant bilateral whole-visual field flickering or pixelation.... (Review)
Review
PURPOSE OF REVIEW
Visual snow is considered a disorder of central visual processing resulting in a perturbed perception of constant bilateral whole-visual field flickering or pixelation. When associated with additional visual symptoms, it is referred to as visual snow syndrome. Its pathophysiology remains elusive. This review highlights the visual snow literature focusing on recent clinical studies that add to our understanding of its clinical picture, pathophysiology, and treatment.
RECENT FINDINGS
Clinical characterization of visual snow syndrome is evolving, including a suggested modification of diagnostic criteria. Regarding pathophysiology, two recent studies tested the hypothesis of dysfunctional visual processing and occipital cortex hyperexcitability using electrophysiology. Likewise, advanced functional imaging shows promise to allow further insights into disease mechanisms. A retrospective study now provides Class IV evidence for a possible benefit of lamotrigine in a minority of patients.
SUMMARY
Scientific understanding of visual snow syndrome is growing. Major challenges remain the subjective nature of the disease, its overlap with migraine, and the lack of quantifiable outcome measures, which are necessary for clinical trials. In that context, refined perceptual assessment, objective electrophysiological parameters, as well as advanced functional brain imaging studies, are promising tools in the pipeline.
Topics: Brain; Functional Neuroimaging; Humans; Perceptual Disorders; Retrospective Studies; Vision Disorders; Visual Perception
PubMed: 31714263
DOI: 10.1097/WCO.0000000000000768 -
Neurologic Clinics May 2021Neuro-ophthalmic emergencies include optic nerve, central visual pathway, and ocular motility disorders that, if not identified and treated promptly, may lead to... (Review)
Review
Neuro-ophthalmic emergencies include optic nerve, central visual pathway, and ocular motility disorders that, if not identified and treated promptly, may lead to permanent vision loss, other significant morbidity, or mortality. This article provides a framework for approaching patients with neuro-ophthalmic symptoms and reviews the presentation, evaluation, and treatment of select emergent conditions that can cause them. Emergent causes of blurry vision, transient vision loss, papilledema, and diplopia, including giant cell arteritis, cardioembolic disease, and aggressive infection, are discussed.
Topics: Emergencies; Humans; Vision Disorders
PubMed: 33896536
DOI: 10.1016/j.ncl.2021.01.004 -
Eye (London, England) Jan 2022Neuro-ophthalmic features are a known association in tuberculosis, especially common in central nervous system tuberculosis (CNS-TB). They are mostly the result of the... (Review)
Review
Neuro-ophthalmic features are a known association in tuberculosis, especially common in central nervous system tuberculosis (CNS-TB). They are mostly the result of the visual pathway and/or ocular motor and other cranial nerve involvement. Furthermore, toxic optic neuropathy and paradoxical response to anti-tubercular drugs (ATT) are also not uncommon. The etiopathogenesis is by the complex interplay of various factors like exudates, vasculitis, arachnoiditis, presence of tuberculomas, hydrocephalus, brain infarcts and/or immune-mediated reaction. The entity often poses a diagnostic dilemma for the ophthalmologists/neuro-ophthalmologists and may lead to irreversible vision loss. The presence of neuro-ophthalmic features not only affect the visual outcome but are also predictors of systemic morbidity of the disease. Therefore, understanding and knowledge about this entity are necessary for the comprehensive management of the disease. While various forms of TB including CNS-TB have been well-dealt with in literature, little is discussed specifically about the neuro-ophthalmic manifestations of tuberculosis. Therefore, the purpose of this review is to highlight current understanding of the types of neuro-ophthalmic involvement in tuberculosis, its etiopathogenesis, diagnosis and management.
Topics: Humans; Tuberculosis; Vision Disorders
PubMed: 34127839
DOI: 10.1038/s41433-021-01619-6 -
Acta Ophthalmologica Sep 2021
Review
A novel excel sheet conversion tool from Snellen fraction to LogMAR including 'counting fingers', 'hand movement', 'light perception' and 'no light perception' and focused review of literature of low visual acuity reference values.
Topics: Humans; Reference Values; Statistics, Nonparametric; Vision Disorders; Vision Tests; Visual Acuity
PubMed: 33326177
DOI: 10.1111/aos.14659 -
Clinical & Experimental Optometry May 2020The state of research on the topic of visual midline shift syndrome following a cerebrovascular accident is unknown. A scoping review was conducted using the search... (Review)
Review
The state of research on the topic of visual midline shift syndrome following a cerebrovascular accident is unknown. A scoping review was conducted using the search terms of 'visual midline shift' (or equivalent) and 'cerebrovascular accident' (or equivalent). Articles were selected from eight academic and one grey literature database, and went through two levels of review, as per Arksey and O'Malley, before being deemed acceptable for inclusion. Of the 931 abstracts reviewed, 27 articles met the criteria for inclusion. Data extracted from the selected articles included terminology and definition, symptoms, underlying pathophysiology, duration, assessment method, and management of visual midline shift syndrome following cerebrovascular accident. There is agreement on the existence of a midline shift following a cerebrovascular accident resulting in poor posture and imbalance. Much uncertainty exists in the literature regarding terminology, underlying pathophysiology, assessment method and management of this condition. Further research is required.
Topics: Humans; Stroke; Syndrome; Vision Disorders; Visual Acuity; Visual Fields
PubMed: 31321827
DOI: 10.1111/cxo.12944 -
Current Neurology and Neuroscience... Apr 2022The purpose of this review is to summarize current approaches to management of functional vision disorder (FVD). (Review)
Review
PURPOSE OF REVIEW
The purpose of this review is to summarize current approaches to management of functional vision disorder (FVD).
RECENT FINDINGS
Several retrospective studies of FVD in both adults and children have shed light on the range of outcomes and the prevalence of psychosocial stressors among FVD patients. While the first line of treatment for FVD is reassurance and education, recent case reports highlight the use of additional treatment modalities including psychotherapy, hypnosis, and transcranial magnetic stimulation in specific cases. Although the epidemiology and diagnosis of functional vision disorder are well described, there is limited evidence supporting treatment modalities. Nevertheless, the majority of patients improve with conservative management including reassurance, education, and appropriate follow-up. Additional approaches such as mental health care referral can be considered in refractory cases.
Topics: Adult; Child; Humans; Prevalence; Retrospective Studies; Transcranial Magnetic Stimulation; Vision Disorders
PubMed: 35320465
DOI: 10.1007/s11910-022-01191-w