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1.
Recurso na Internet em Português | LIS - Localizador de Informação em Saúde, LIS-bvsms | ID: lis-LISBR1.1-46943

RESUMO

Miopia é um distúrbio visual cuja principal característica é a dificuldade de ver de longe.


Assuntos
Miopia , Visão Ocular , Oftalmologia
2.
Zhonghua Yan Ke Za Zhi ; 56(1): 61-65, 2020 Jan 11.
Artigo em Chinês | MEDLINE | ID: mdl-31937065

RESUMO

Visual evoked potential (VEP) is often used for the objective evaluation for impairment of visual function. Although these VEP-related tests have good results in the assessment of glaucoma, their application as routine tests in the clinical diagnosis of glaucoma is limited due to the time consumption and easy interference by the environment and the reliance on the experience of the doctors. However, several new VEP detection modes have emerged in the past decade, such as short-duration transient VEP and isolated check VEP. Preliminary studies have shown that both of them have good diagnostic ability in glaucoma, and more studies on the clinical application of these latest technologies are conducive to further understanding of their value in the visual function evaluation and follow-up of glaucoma. (Chin J Ophthalmol, 2020, 56: 61-65).


Assuntos
Potenciais Evocados Visuais , Glaucoma , Visão Ocular/fisiologia , Acuidade Visual/fisiologia , Progressão da Doença , Humanos
3.
Adv Exp Med Biol ; 1185: 145-149, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31884603

RESUMO

Despite the many promising therapeutic approaches identified in the laboratory, it has proven extremely challenging to translate basic science advances into the eye clinic. There are many recent examples of clinical trials (e.g., Holz FG, Sadda SR, Busbee B, JAMA Ophthalmology 136:666-677, 2018) failing at the most expensive phase three stage, unable to demonstrate efficacy in the patient population. As a community we must think carefully about how we select what goes into that pipeline. Translating vision restoration therapies from the bench to the bedside involves selecting the most appropriate animal models of retinal degeneration and then moving beyond morphology to deploy appropriate functional tests in vitro, in vivo, and in the clinic. In this review we summarize the functional assays available to researchers, future prospects, and highlight areas in need of further development.


Assuntos
Degeneração Retiniana/terapia , Visão Ocular , Animais , Humanos
4.
Adv Exp Med Biol ; 1185: 489-493, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31884659

RESUMO

High visual acuity and the ability to identify colours is solely dependent upon healthy cone photoreceptors in the retina. Little is known about cone migration mechanisms during postmitotic retinal maturation which, if it occurs erroneously, can result in non-functional cells and altered vision. This review provides an overview of neuronal and cone somal migration mechanisms and the potential molecular partners and nuclear structures driving this process. Furthermore, it will also review foveal formation and how that differs from peripheral cone migration in the human retina.


Assuntos
Movimento Celular , Retina/citologia , Células Fotorreceptoras Retinianas Cones/citologia , Animais , Fóvea Central , Humanos , Visão Ocular , Acuidade Visual
5.
Invest Ophthalmol Vis Sci ; 60(14): 4556-4563, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31675073

RESUMO

Purpose: To determine the importance of various vision parameters to functionality in glaucoma. Methods: Vision was measured using seven parameters: visual acuity (VA), contrast sensitivity (CS), integrated visual field (IVF), area under the log CS function (AULCSF), color vision, stereoacuity, and VA with noise (ViN). Likelihood ratio testing (LRT) determined if the full set of visual parameters significantly explained variability in 10 functional outcomes. For outcomes where the visual contribution was significant, dominance analysis determined the relative importance of the various visual parameters. Results: The analysis included 151 glaucoma patients. Mean age was 70 ± 6.8 years, and 47% were men. Significant visual contributions (LRT P < 0.05) were noted for glaucoma quality of life (GQL-15), reading speed, driving cessation, daily steps, and base of support while walking, but not for fear of falling, balance, gait velocity, stride velocity, and stride length while walking (LRT P > 0.05). The most important parameter (and percent contribution) to vision-explained variability were AULCSF for daily steps (45%), IVF for base of support (35%), VA for reading speed (34%), CS for GQL-15 (30%), and VA for driving cessation (26%). Conclusions: Measures of visual ability are important for several aspects of quality of life and functionality. The most important vision parameter for functionality differs depending on the domain studied. Reading and driving were explained by VA and IVF sensitivity. On the other hand, GQL-15 and daily steps were more heavily influenced by CS and AULCSF, which are rarely performed clinically.


Assuntos
Visão de Cores/fisiologia , Sensibilidades de Contraste/fisiologia , Glaucoma/fisiopatologia , Visão Ocular/fisiologia , Acuidade Visual/fisiologia , Campos Visuais/fisiologia , Idoso , Condução de Veículo , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Qualidade de Vida , Leitura , Perfil de Impacto da Doença , Inquéritos e Questionários
6.
Ophthalmic Physiol Opt ; 39(6): 459-468, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31696535

RESUMO

PURPOSE: Optical filters and tints manipulating short-wavelength light (sometimes called 'blue-blocking' or 'blue-attenuating' filters) are used in the management of a range of ocular, retinal, neurological and psychiatric disorders. In many cases, the only available quantification of the optical effects of a given optical filter is the spectral transmittance, which specifies the amount of light transmitted as a function of wavelength. METHODS: We propose a novel physiologically relevant and retinally referenced framework for quantifying the visual and non-visual effects of these filters, incorporating the attenuation of luminance (luminous transmittance), the attenuation of melanopsin activation (melanopsin transmittance), the colour shift, and the reduction of the colour gamut (gamut reduction). Using these criteria, we examined a novel database of spectral transmittance functions of optical filters (n = 121) which were digitally extracted from a variety of sources. RESULTS: We find a large diversity in the alteration of visual and non-visual properties. The spectral transmittance properties of the examined filters vary widely, in terms of shapes and cut-off wavelengths. All filters show relatively more melanopsin attenuation than luminance attenuation (lower melanopsin transmittance than luminous transmittance). Across the data set, we find that melanopsin transmittance and luminous transmittance are correlated. CONCLUSIONS: We suggest that future studies and examinations of the physiological effects of optical filters quantify the visual and non-visual effects of the filters beyond the spectral transmittance, which will eventually aid in developing a mechanistic understanding of how different filters affect physiology. We strongly discourage comparing the downstream effects of different filters on, e.g. sleep or circadian responses, without considering their effects on the retinal stimulus.


Assuntos
Luz , Óptica e Fotônica , Estimulação Luminosa/métodos , Retina/fisiologia , Visão Ocular/fisiologia , Humanos , Opsinas de Bastonetes/metabolismo , Opsinas de Bastonetes/efeitos da radiação
8.
Invest Ophthalmol Vis Sci ; 60(14): 4681-4690, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31725167

RESUMO

Purpose: To compare the effects of reduced inhibitory neuron function in the retina across behavioral, physiological, and anatomical levels. Methods: Inhibitory neurons were ablated in larval zebrafish retina. The Ptf1a gene, which determines inhibitory neuron fate in developing vertebrates, was used to express nitroreductase. By exposing larvae to the prodrug metronidazole, cytotoxicity was selectively induced in inhibitory neurons. Visual phenotypes were characterized at behavioral, physiological, and anatomical levels using an optomotor response (OMR) assay, electroretinography (ERG), and routine histology, respectively. Nonvisual locomotion was also assessed to reveal any general behavioral effects due to ablation of other nonvisual neurons that also express Ptf1a. Results: Injured larvae showed severely reduced OMR relative to controls. Locomotor assessment showed unaltered swimming ability, indicating that reduced OMR was due to visual deficits. For ERG, injured larvae manifested either reduced (type-I) or absent (type-II) b-wave signals originating from bipolar interneurons in the retina. Histologic analysis showed altered retinal morphology in injured larvae, with reductions in synaptic inner plexiform layer (IPL) thickness and synaptic density more pronounced in type-II than type-I larvae; type-II larvae also had smaller retinae overall. Conclusions: The consequences of inhibitory neuron ablation corresponded closely across behavioral, physiological, and anatomical levels. Inhibitory neuron loss likely increases the ratio of neural excitation to inhibition, leading to hyperexcitability. In addition to modulating visual signals, inhibitory neurons may be critical for maintaining retinal structure and organization. This study highlights the utility of a multidisciplinary approach and provides a template for characterizing other zebrafish models of neurological disease.


Assuntos
Anti-Infecciosos/toxicidade , Comportamento Animal/fisiologia , Metronidazol/toxicidade , Neurônios Motores/efeitos dos fármacos , Retina/fisiologia , Visão Ocular/fisiologia , Animais , Animais Geneticamente Modificados , Eletrorretinografia , Larva , Neurônios Motores/metabolismo , Nitrorredutases/metabolismo , Estimulação Luminosa , Transdução de Sinais , Fatores de Transcrição/metabolismo , Peixe-Zebra
9.
Biol Lett ; 15(10): 20190554, 2019 10 31.
Artigo em Inglês | MEDLINE | ID: mdl-31640527

RESUMO

Eye regression occurs across cave-dwelling populations of many species and is often coupled with a decrease or loss in eye function. Teleost fishes are among the few vertebrates to undergo widespread colonization of caves and often exhibit eye regression with blindness. Cave populations of the poeciliid fish Poecilia mexicana (cave molly) exhibit reduced-albeit functional-eyes, offering the opportunity to investigate partial eye regression. We sequenced eye transcriptomes of cave and surface populations of P. mexicana to identify differentially expressed genes that potentially underlie eye regression in cave mollies. We identified 28 significantly differentially expressed genes, 20 of which were directly related to light sensitivity, eye structure and visual signaling. Twenty-six of these genes were downregulated in cave compared to surface populations. Functional enrichment analysis revealed eye-related gene ontologies that were under-represented in cave mollies. In addition, a set of co-expressed genes related to vision and circadian rhythm was correlated with habitat type (cave versus surface). Our study suggests that differential gene expression plays a key role in the beginning evolutionary stages of eye regression in P. mexicana, shedding further light on regressive evolution in cavefish.


Assuntos
Poecilia , Animais , Sequência de Bases , Evolução Biológica , Cavernas , Ecossistema , Olho , Visão Ocular
10.
Fa Yi Xue Za Zhi ; 35(4): 402-405, 2019 Aug.
Artigo em Inglês, Chinês | MEDLINE | ID: mdl-31532146

RESUMO

Abstract: Objective To research the correlation between the visual acuity ratio and pattern reversal visual evoked potential (PRVEP) P100 waveform amplitude ratio of both eyes. Methods Forty-seven volunteers were selected, and the visual chart visual acuity of both eyes was measured. The visual acuity ratio of the eye with poor vision to the eye with better vision was calculated by five grade notation method. The amplitudes of P100 waveforms of both eyes were recorded respectively by using black-and-white checkerboard PRVEP and chosing 1°, 15' stimulating visual angle, and the ratio of amplitudes between the two eyes was also calculated. SPSS 20.0 software was used to analyze the correlation between the visual acuity ratio and the ratio of P100 waveform amplitudes between the two eyes. Return test and linear regression analysis with the binocular ratio of P100 waveform amplitudes as the independent variable (x) and the binocular visual acuity ratio as the dependent variable (y) were made. Results There was a positive correlation between the binocular visual acuity ratio and the ratio of P100 waveform amplitudes under 15' stimulating visual angle (Pearson correlation coefficient was 0.62, P=0.000). The fitting linear regression equation was y=0.090 x+0.846 (F=20.954, P=0.000). There was no significant correlation between the binocular ratio of visual acuity and the binocular ratio of P100 waveform amplitudes under 1° stimulating visual angle (P>0.05). Results of return test showed that there was no statistical significance in the difference between visual acuity estimated by equation and actual detected visual acuity. Conclusion In forensic appraisal of monocular injury, fitting linear regression equation of binocular visual acuity ratio and the binocular ratio of P100 waveform amplitudes under 15' stimulating visual angle, is helpful for visual acuity level estimation of the injured eye to some extent.


Assuntos
Potenciais Evocados Visuais , Olho/fisiopatologia , Visão Ocular , Acuidade Visual , Humanos , Análise de Regressão
11.
Nature ; 574(7776): 108-111, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31534223

RESUMO

Light discrimination according to colour can confer survival advantages by guiding animals towards food and shelter and away from potentially harmful situations1,2. Such colour-dependent behaviour can be learned or innate. Data on innate colour preference in mammals remain controversial3 and there are limited data for simpler organisms4-7. Here we show that, when given a choice among blue, green and dim light, fruit flies exhibit an unexpectedly complex pattern of colour preference that changes according to the time of day. Flies show a strong preference for green in the early morning and late afternoon, a reduced green preference at midday and a robust avoidance of blue throughout the day. Genetic manipulations reveal that the peaks in green preference require rhodopsin-based visual photoreceptors and are controlled by the circadian clock. The midday reduction in green preference in favour of dim light depends on the transient receptor potential (TRP) channels dTRPA1 and Pyrexia, and is also timed by the clock. By contrast, avoidance of blue light is primarily mediated by multidendritic neurons, requires rhodopsin 7 and the TRP channel Painless, and is independent of the clock. Our findings show that several TRP channels are involved in colour-driven behaviour in Drosophila, and reveal distinct pathways of innate colour preference that coordinate the behavioural dynamics of flies in ambient light.


Assuntos
Relógios Circadianos/fisiologia , Relógios Circadianos/efeitos da radiação , Cor , Drosophila melanogaster/fisiologia , Drosophila melanogaster/efeitos da radiação , Luz , Canais de Receptores Transientes de Potencial/metabolismo , Animais , Antenas de Artrópodes/fisiologia , Antenas de Artrópodes/efeitos da radiação , Dendritos/fisiologia , Dendritos/efeitos da radiação , Drosophila melanogaster/crescimento & desenvolvimento , Feminino , Larva/fisiologia , Larva/efeitos da radiação , Luz/efeitos adversos , Masculino , Neurônios/fisiologia , Neurônios/efeitos da radiação , Rodopsinas Sensoriais/metabolismo , Fatores de Tempo , Visão Ocular/efeitos da radiação
12.
J Autism Dev Disord ; 49(12): 4901-4918, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31489542

RESUMO

Visual perception in individuals with autism spectrum disorder (ASD) is often debated in terms of enhanced local and impaired global perception. Deficits in global motion perception seem to support this characterization, although the evidence is inconsistent. We conducted a large meta-analysis on global motion, combining 48 articles on biological and coherent motion. Results provide evidence for a small global motion processing deficit in individuals with ASD compared to controls in both biological and coherent motion. This deficit appears to be present independent of the paradigm, task, dependent variable, age or IQ of the groups. Results indicate that individuals with ASD are less sensitive to these types of global motion, although the difference in neural mechanisms underlying this behavioral difference remains unclear.


Assuntos
Transtorno do Espectro Autista/fisiopatologia , Percepção de Movimento , Adolescente , Adulto , Movimentos Oculares , Feminino , Humanos , Masculino , Visão Ocular
13.
Ophthalmologe ; 116(9): 897-898, 2019 09.
Artigo em Alemão | MEDLINE | ID: mdl-31482234

Assuntos
Visão Ocular , Animais , Cães
14.
Nat Commun ; 10(1): 3910, 2019 09 02.
Artigo em Inglês | MEDLINE | ID: mdl-31477706

RESUMO

Vision relies on both specific knowledge of visual attributes, such as object categories, and general brain states, such as those reflecting arousal. We hypothesized that these phenomena independently influence recognition of forthcoming stimuli through distinct processes reflected in spontaneous neural activity. Here, we recorded magnetoencephalographic (MEG) activity in participants (N = 24) who viewed images of objects presented at recognition threshold. Using multivariate analysis applied to sensor-level activity patterns recorded before stimulus presentation, we identified two neural processes influencing subsequent subjective recognition: a general process, which disregards stimulus category and correlates with pupil size, and a specific process, which facilitates category-specific recognition. The two processes are doubly-dissociable: the general process correlates with changes in criterion but not in sensitivity, whereas the specific process correlates with changes in sensitivity but not in criterion. Our findings reveal distinct mechanisms of how spontaneous neural activity influences perception and provide a framework to integrate previous findings.


Assuntos
Reconhecimento Visual de Modelos/fisiologia , Visão Ocular/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Adulto , Algoritmos , Feminino , Humanos , Magnetoencefalografia , Masculino , Modelos Neurológicos , Estimulação Luminosa/métodos , Adulto Jovem
15.
Gait Posture ; 73: 286-290, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31398634

RESUMO

INTRODUCTION: Visual skills are an integral part of most daily activities and an effective indicator of the functional ability of athletes, particularly in the fields of dynamic sports like basketball. Despite the important role of vision and effect of ocular exercises on functional skills in athletes, a few studies have been conducted in this regard. Thus, this study aimed to investigate the effect of ocular-motor exercises on dynamic visual acuity and stability limit of female basketball players. METHODS: In this semi-experimental study 30 club elite female basketball players aged between 18 and 24 years, with at least three years of specialized basketball experience, were randomly assigned to two intervention and control groups. The athletes in the intervention group participated in the designed four-week program (six sessions per week) of the oculo_motor exercises. The control group did just their own daily routine exercises. The limit of stability was measured by the Biodex balance system SD and dynamic visual acuity was measured by the PowerPoint, which is for detecting dynamic visual acuity. Also, the SPSS software version 19 was used to analyze the data by using descriptive statistics methods: independent t and Paired t tests, at a significance level of P ≤ 0.05. RESULTS: The results showed that doing four weeks of the oculo_motor exercises led to a significant increase in the overall stability index (OSI) from 28/66 ±â€¯7/23 to 51/60 ±â€¯6/38 (p = 0.001), as well as in dynamic visual acuity from 29/73 ±â€¯4/19 to 56/20 ±â€¯8/81(p < 0.001); in the intervention group, these changes were also statistically significant in comparison with the control group and before doing the exercise protocol (p < 0.05). CONCLUSION: According to the obtained results, the oculo_motor exercises can be used to enhance the limit of stability and dynamic visual acuity in basketball players and other dynamic sports.


Assuntos
Atletas , Terapia por Exercício/métodos , Movimentos Oculares/fisiologia , Músculos Oculomotores/fisiologia , Equilíbrio Postural , Acuidade Visual , Adolescente , Desempenho Atlético , Basquetebol , Feminino , Humanos , Visão Ocular , Adulto Jovem
16.
J Stroke Cerebrovasc Dis ; 28(11): 104296, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31395425

RESUMO

OBJECTIVES: This study was designed to investigate the effect of prism adaptation (PA) combined with continuous theta-burst transcranial magnetic stimulation (cTBS) on the neglect recovery of stroke patients with unilateral neglect. METHODS: A total of 14 stroke patients with unilateral neglect were randomly assigned to 2 groups including an intervention group undergone PA combined with cTBS over the left intact parietal cortex and a control group. PA combined with sham cTBS was perfomed for 2 weeks in 10 daily sessions. Before and after the intervention, patients were evaluated for visuospatial neglect measured using the Star Cancellation Test (SCT), Line Bisection Task (LBT), Figure Copying Test, and Clock Drawing Task. Neurological function was evaluated using the Modified Rankin Scale (MRS). RESULTS: Both groups (PA alone and PA+ cTBS) showed improvement in their neglected symptoms (measured by SCT, LBT, Figure Copying Test, and Clock Drawing Task), and in their disability in the neurological function (measured by MRS) (P< .05). CONCLUSIONS: The results of the present study showed that, transcranial magnetic stimulation did not increase the effect of PA on neglect symptoms in stroke patients.


Assuntos
Agnosia/reabilitação , Ritmo beta , Encéfalo/fisiopatologia , Óculos , Reabilitação do Acidente Vascular Cerebral/instrumentação , Acidente Vascular Cerebral/terapia , Estimulação Magnética Transcraniana , Visão Ocular , Percepção Visual , Idoso , Agnosia/diagnóstico , Agnosia/fisiopatologia , Agnosia/psicologia , Terapia Combinada , Avaliação da Deficiência , Feminino , Lateralidade Funcional , Humanos , Masculino , Pessoa de Meia-Idade , Atividade Motora , Projetos Piloto , Recuperação de Função Fisiológica , Acidente Vascular Cerebral/diagnóstico , Acidente Vascular Cerebral/fisiopatologia , Acidente Vascular Cerebral/psicologia , Reabilitação do Acidente Vascular Cerebral/efeitos adversos , Fatores de Tempo , Estimulação Magnética Transcraniana/efeitos adversos , Resultado do Tratamento
17.
BMC Biol ; 17(1): 67, 2019 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-31416484

RESUMO

BACKGROUND: Arthropod eyes have diversified during evolution to serve multiple needs, such as finding mates, hunting prey and navigating in complex surroundings under varying light conditions. This diversity is reflected in the optical apparatus, photoreceptors and neural circuits that underpin vision. Yet our ability to genetically manipulate the visual system to investigate its function is largely limited to a single species, the fruit fly Drosophila melanogaster. Here, we describe the visual system of Parhyale hawaiensis, an amphipod crustacean for which we have established tailored genetic tools. RESULTS: Adult Parhyale have apposition-type compound eyes made up of ~ 50 ommatidia. Each ommatidium contains four photoreceptor cells with large rhabdomeres (R1-4), expected to be sensitive to the polarisation of light, and one photoreceptor cell with a smaller rhabdomere (R5). The two types of photoreceptors express different opsins, belonging to families with distinct wavelength sensitivities. Using the cis-regulatory regions of opsin genes, we established transgenic reporters expressed in each photoreceptor cell type. Based on these reporters, we show that R1-4 and R5 photoreceptors extend axons to the first optic lobe neuropil, revealing striking differences compared with the photoreceptor projections found in related crustaceans and insects. Investigating visual function, we show that Parhyale have a positive phototactic response and are capable of adapting their eyes to different levels of light intensity. CONCLUSIONS: We propose that the visual system of Parhyale serves low-resolution visual tasks, such as orientation and navigation, based on broad gradients of light intensity and polarisation. Optic lobe structure and photoreceptor projections point to significant divergence from the typical organisation found in other malacostracan crustaceans and insects, which could be associated with a shift to low-resolution vision. Our study provides the foundation for research in the visual system of this genetically tractable species.


Assuntos
Anfípodes/fisiologia , Células Fotorreceptoras de Invertebrados/fisiologia , Visão Ocular/fisiologia , Percepção Visual/fisiologia , Animais , Fototaxia/fisiologia
18.
Swiss Dent J ; 129(11): 922-928, 2019 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-31460731

RESUMO

The aim of this study was to evaluate the performance of Galilean and Keplerian loupes in the endodontic lumen with and without integrated light. Although the use of an operating microscope is widely recommended in endodontics it is uncertain whether an adequate loupe system with coaxial light source might replace the microscope for some endodontic work. Twenty-four dentists (age 27­64 years) underwent a miniaturized visual test inside the endodontic lumen of a natural molar: at the canal entrance, 5 mm inside the canal, and at the apex. The tooth was mounted in a phantom head in a simulated clinical setting. The naked eye (negative) and the microscope 6× (positive) served as control groups, and Galilean loupes 2.5× and Keplerian loupes 4.3× with and without a coaxial light source as experimental groups. A structure of 0.05 mm corresponding to the smallest instrument (06) was the threshold for sufficient vision. The loupe type, coaxial light source and the dentists' age had a statistically significant influence at all locations. None of the loupes helped to visualize structures at the apex. At the canal entrance, the visual threshold was reached by dentists < 40 years with Galilean loupes, by dentists ≥ 40 years with Keplerian loupes, with and without coaxial light. Dentists < 40 years detected structures < 0.05 mm inside the root canal with Keplerian loupes and coaxial light. The microscope offered highly superior results. The naked eye was insufficient to reach the visual threshold at any location.


Assuntos
Instrumentos Odontológicos , Odontólogos , Endodontia , Microscopia/instrumentação , Visão Ocular , Adulto , Estudos de Casos e Controles , Assistência Odontológica , Feminino , Humanos , Lentes , Masculino , Pessoa de Meia-Idade , Miniaturização , Testes Visuais
19.
J Environ Public Health ; 2019: 3813298, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428165

RESUMO

Purpose: The aim of this study was to analyse eye health delivery in Ghana and examine the progress towards achieving VISION 2020 indicator targets. Methods: This descriptive cross-sectional study was conducted between October 2017 and May 2018. It used a mixed method approach including desk-based reviews, a questionnaire-based survey of eye facilities in Ghana, and interviews with eye health system stakeholders to collect information on eye health delivery in facilities owned by the Ghana Health Service (GHS), quasigovernmental bodies (security agencies), and Christian Association of Ghana (CHAG). The information was benchmarked against the World Health Organization (WHO) targets for achieving the goals of VISION 2020. Results: The magnitude of blindness and moderate to severe visual impairment (without pinhole) was 0.9% and 3.0%, respectively. The number of ophthalmologists available at the country level was 80.6% of the VISION 2020 target with optometrists and ophthalmic nurses exceeding targets for VISION 2020. The distribution of human resources was heavily skewed towards two out of the 10 regions in Ghana. Cataract surgical rate was low and met 25% of the WHO target. Basic equipment for refraction was available in the majority of facilities; however, there was a general lack of specialised eye care equipment across the country. Comparatively, CHAG facilities were better equipped than GHS facilities at the same level. Conclusion: The Government of Ghana should revitalize the goals of VISION 2020 beyond the year 2020 and spearhead a concerted effort to ensure equitable distribution of human and infrastructural resources across the country.


Assuntos
Assistência à Saúde/estatística & dados numéricos , Visão Ocular , Cegueira/epidemiologia , Extração de Catarata/estatística & dados numéricos , Estudos Transversais , Assistência à Saúde/organização & administração , Gana/epidemiologia , Pesquisas sobre Serviços de Saúde , Mão de Obra em Saúde/estatística & dados numéricos , Humanos , Oftalmologia/estatística & dados numéricos , Optometria/estatística & dados numéricos
20.
J Vis ; 19(9): 10, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31434106

RESUMO

Prediction allows humans and other animals to prepare for future interactions with their environment. This is important in our dynamically changing world that requires fast and accurate reactions to external events. Knowing when and where an event is likely to occur allows us to plan eye, hand, and body movements that are suitable for the circumstances. Predicting the sensory consequences of such movements helps to differentiate between self-produced and externally generated movements. In this review, we provide a selective overview of experimental studies on predictive mechanisms in human vision for action. We present classic paradigms and novel approaches investigating mechanisms that underlie the prediction of events guiding eye and hand movements.


Assuntos
Movimento/fisiologia , Desempenho Psicomotor/fisiologia , Visão Ocular/fisiologia , Retroalimentação Sensorial/fisiologia , Metas , Humanos
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