Дисертації з теми "Vision disorders"

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1

Conner, Ian Patrick. "fMRI studies of amblyopia pediatric and adult perspectives /." Morgantown, W. Va. : [West Virginia University Libraries], 2005. https://eidr.wvu.edu/etd/documentdata.eTD?documentid=4077.

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Thesis (Ph. D.)--West Virginia University, 2005.
Title from document title page. Document formatted into pages; contains xi, 199 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.
2

Ajzenman, Heather. "Binocular vision skills in human observers /." South Hadley, Mass. : [s.n.],, 2008. http://ada.mtholyoke.edu/setr/websrc/pdfs/www/2008/293.pdf.

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3

Faulkner, Stuart. "The nature of binocular interactions in developmental disorders of vision." Thesis, Cardiff University, 2004. http://orca.cf.ac.uk/55414/.

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4

Bryer, Alan. "Pseudotumor cerebri (with special reference to visual loss)." Master's thesis, University of Cape Town, 1988. http://hdl.handle.net/11427/26342.

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AIMS OF STUDY: 1. To analyse the patients . who have been treated at Groote Schuur Hospital over the last seven years for Pseudotumor Cerebri. 2. To document the clinical features of this group of patients. 3. To determine the visual prognosis of this group. 4. To assess the forms of treatment that have been used in this group. 5. To review the literature with regard to: a) a comparison of the results of other studies with the present one. b) the pathophysiology of the condition. c) treatment of the syndrome. d) the visual prognosis of the syndrome.
5

McColl, Shelley L. "Interictal visual system function in migraine : a psychophysical approach." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82931.

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Visual manifestations of migraine are largely considered transient, without permanent sequelae. Recent findings raise the possibility of persistent ocular and neural manifestations. This thesis investigates visual function in migraine during the period between episodes by applying various psychophysical tests to two migraine groups (migraine with aura ( n = 20) and migraine without aura (n = 20)) and comparing the results to those of a nonheadache control group (n = 20). Tests were designed to address the level of visual system involvement, and to investigate the extent to which selective visual processes, specifically, motion and other forms of temporal modulation are adversely affected in migraine.
The first experiment assessed global processing of complex form and motion in Glass patterns. Compared to nonheadache participants, the migraine groups demonstrated significantly elevated motion detection than motion discrimination thresholds. In contrast, average form detection thresholds were almost identical between subject groups. The second experiment measured perimetrically, in each eye, global motion sensitivity in fifteen localized visual field regions and compared these results in the same subjects to those obtained from conventional luminance-based perimetry. Perimetry testing revealed that two-thirds of migraineurs had localized deficits in motion coherence. Almost all motion field defects occurred in regions of normal sensitivity to the luminance targets. Over 80% of migrainous visual field defects were nonhomonymous, indicating that dysfunction occurs largely prior to the optic chiasm. Homonymous defects were also detected, raising the possibility of postchiasmal dysfunction, although several of these defects may represent independent monocular losses. The stability of a sample of field defects was retested after a 4--6 week delay. Sixty-percent of the motion defects persisted. These regions could support normal resolution acuity, but in most cases, not the discrimination of small increments in speed in globally coherent motion.
Also included is a study of the spatial and temporal frequency characteristics of visual discomfort to grating patterns. Visual discomfort was experienced by a greater proportion of migraineurs than nonheadache controls, and at significantly lower levels of stimulus contrast in migraineurs than in controls. Gratings modulated at high temporal frequencies were particularly effective in eliciting discomfort in migraineurs.
Comparison of individual results across the various tests suggests that functional deficits in migraine (i) are demonstrated on tasks that involve global motion and other forms of temporal modulation, (ii) occur primarily prior to the optic chiasm, but may, in some cases, also involve higher-levels of the visual pathway. Theoretical and clinical implications on migraine pathology and the visual system are discussed.
6

Kvarnström, Gun. "Visual screening of children in Sweden : epidemiological and methodological aspects /." Linköping : Univ, 2004. http://www.bibl.liu.se/liupubl/disp/disp2004/med852s.pdf.

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7

Marquardt, Westlake Laura L. "Effectiveness of five vision screening instruments for detecting possible amblyogenetic factors in young children." Laramie, Wyo. : University of Wyoming, 2005. http://proquest.umi.com/pqdweb?did=1051260181&sid=2&Fmt=2&clientId=18949&RQT=309&VName=PQD.

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8

Carkeet, Andrew D. "Spatio-temporal characteristics of vision in glaucomatous and normal subjects." Thesis, Queensland University of Technology, 1995. https://eprints.qut.edu.au/36727/1/36727_Digitised%20Thesis.pdf.

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This study investigated the ability of normal subjects and glaucoma patients to judge the temporal order of small, foveally presented stimuli. Two basic stimulus paradigms were used: Inter-Ocular Temporal Asynchrony (IOTA), and Temporal Order Discrimination (TOD). IOTA, a simple foveal dichoptic temporal order matching technique, was designed to investigate whether the visual system in glaucoma is characterised by interocular asymmetry of visual latency. Preliminary testing showed that IOTA was affected by monocular luminance attenuation using ND filters in normal subjects. Glaucoma subjects showed significant abnormalities on IOTA testing which correlated strongly with asymmetry of optic disc appearance, and less strongly with asymmetry of visual field indices. This is the first perceptual evidence of alterations in visual latency in glaucoma patients, and is in accord with previous findings that glaucoma causes increased latency in visually evoked potential responses. TOD was a monocular foveal test, measuring the smallest interstimulus interval required by a subject to distinguish the temporal order of two spatially proximal stimuli. As there had been little previous research in normal subjects on the effects of stimulus duration, contrast and temporal profile on TOD, these parameters were investigated for a small number of young, visually normal subjects. For constant contrast stimuli with rectangle temporal profiles, TOD thresholds depended on stimulus duration, performance being optimal for durations around 10 to 100 ms, and thresholds increasing for longer and briefer stimulus durations. For stimuli set at 4 times contrast threshold, TOD thresholds were constant for brief durations, but increased (i.e. became poorer) for longer durations. This duration-dependent increase in TOD thresholds was more marked for stimuli with Gaussian temporal profiles than for rectangular profile stimuli, suggesting that the high frequency information contained in the edges of rectangular pulses aided TOD judgments. TOD thresholds improved with increasing stimulus contrast, although the degree of improvement varied with stimulus duration, and between subjects. TOD performance was measured in glaucoma patients, age-matched old normal subjects, and young normal subjects. Stimuli with Gaussian temporal envelopes were used, and contrasts set at 4 times individual subject's contrast threshold so that all stimuli would be equally visible. Stimulus durations were varied over a large range (pulse standard deviations of 16, 64, and 256 ms). Older subjects showed increased TOD thresholds (i.e. poorer performance) compared to young normal subjects, and this was true for all stimulus durations. This result cannot be explained in terms of increased sluggishness of the aging visual system, but suggests that TOD processing of high and low temporal frequency information is impaired in older observers. The TOD thresholds of glaucoma patients did not differ significantly from· those of age-matched normals for all durations tested, despite the fact that glaucoma subjects had, on average, significantly poorer foveal contrast detection thresholds, greater optic disc cupping and a higher degree of visual field loss than for age-matched normals. For clinical testing of foveal function in glaucoma, contrast threshold measurement is of greater diagnostic value than TOD measurement. The subjects in each of the three groups were tested with MOTA (Monocular Temporal Asynchrony), a "method of adjustment" measure of temporal order matching ability. This technique was trialed because its speed of measurement offered an advantage over TOD in clinical testing. However MOTA showed poor potential as a substitute for TOD, correlating only weakly with TOD for the three groups, and being unable to distinguish glaucoma from age-matched normal subjects. In summary, glaucoma appears to cause interocular asymmetry of perceived latency, but does not affect precision of temporal order judgments, even in patients who show elevated foveal contrast thresholds.
9

Crotogino, Jennifer. "Visual stress in migraine : subjective and psychophysiological responses to intense visual stimulation." Thesis, McGill University, 2002. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38475.

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This dissertation assesses whether intense visual stimulation can act as a stressor to migraine sufferers between attacks, and whether subjective and psychophysiological reactions to these stimuli can clarify how migraine attacks may be triggered.
The first study assessed thresholds of light-induced discomfort and pain in migraine sufferers and non-migrainous controls during a non-headache period. Two instruction sets were compared to assess whether information presented to participants would affect thresholds. The results showed that migraineurs had significantly lower thresholds for light-induced pain. However, this effect was most apparent in those who had heard the negatively biased instructions reinforcing the need to control contextual factors when assessing subjective phenomena such as visual discomfort.
The second study assessed subjective and psychophysiological responses of female migraine sufferers and female controls during exposure to visual stimuli incorporating spatial and temporal characteristics that are most likely to be bothersome to migraineurs. Two control stimuli were included to assess responses during similar, but theoretically less aversive conditions. Migraine sufferers had higher heart rate and more frequent electrodermal responses than controls at all points of the study, including baseline and recovery. However, while migraineurs reported higher anxiety during the intense conditions, and reported more visual and somatic complaints than controls during various viewing conditions, they did not show heart rate, heart rate variability or electrodermal changes that would suggest clear changes in autonomic function in response to aversive visual stimulation.
The third study assessed ambulatory electrocardiograms to investigate whether autonomic changes would be evident in the period leading up to, during or following a migraine. Three individuals were assessed on a day when they experienced a naturally occurring headache, and on a day when they were not. No obvious pattern of autonomic change was detected before or after headache, although there was some evidence that a pattern of increased heart rate and decreased vagal tone may accompany headache.
In summary, the results confirm that migraine sufferers are more sensitive to intense visual stimulation than controls, but do not support the contention that exposure results in widespread autonomic changes. Since interictal visual discomfort is a common in migraine, further research is needed to clarify how it can be incorporated into models of migraine pathophysiology.
10

Wang, Chongwen. "The impacts of psycho-social-spiritual factors on health-related quality of life among Chinese older adults with visual problems." Click to view the E-thesis via HKUTO, 2006. http://sunzi.lib.hku.hk/hkuto/record/B37044394.

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11

Schultz, Geoffrey Robert. "Complex visual hallucinations associated with deficits in vision : the Charles Bonnet Syndrome." Thesis, McGill University, 1995. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=40243.

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The Charles Bonnet syndrome is characterized by complex visual hallucinations in people without psychopathology or disturbance of normal consciousness. This thesis highlights the association of visual deficits with the syndrome, and proposes that it is analogous to the perception of phantom limbs; both conditions arise when normal sensory input to the brain is severely reduced. The five studies that comprise this thesis systematically gather information on the syndrome to answer three basic questions: how can the hallucinations be classified, what are the clinical implications for individuals who experience them, and what might cause the hallucinations. Study 1 examines 64 cases described in the literature. Demographic information on the hallucinators, properties of the hallucinations, initiating factors, as well as etiological mechanisms are reviewed. Study 2 examines the properties of the hallucinations in a sample of 60 subjects and reveals, by statistical analysis, a dimension of the hallucinatory experience that ranges from discrete, singular perceptual experiences to multiple changing experiences. Studies 3 and 4 examine the mental status of hallucinators score within the normal range on tests of anxiety, depression, and psychological symptomology and exhibit no evidence of gross cognitive impairment. A detailed analysis of results show that a small proportion of hallucinators score within the normal range on tests of anxiety, depression, and psychological symptomology and exhibit no evidence of gross cognitive impairment. A detailed analysis of results show that a small proportion of hallucinators endorse comparatively more symptom-oriented items than the remainder of hallucinators, as well as more items non-hallucinators (in Study 4). Finally, Study 5 examines the performance of two hallucinating groups as well as a group of visually impaired non-hallucinating on threshold estimation and signal detection tasks. The results of the combined studies indicate
12

Knight, Lelia. "Vision impairment in older adults : adaptation strategies and the Charles Bonnet syndrome." Thesis, McGill University, 2006. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=100741.

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Adaptation to vision impairment was studied by telephone interviews with 78 legally blind adults (mean age 79.5) who had received rehabilitation services from an agency in upstate New York. Data were collected on demographics, health, activity levels, social support, blindness data, adaptation to vision loss (AVL scale, Horwitz and Reinhardt, 2005), and symptoms of Charles Bonnet Syndrome (CBS). Using multiple regression and logistic regression, the most significant predictors of high AVL scores were found to be good interpersonal communication and a relative living close by, while predictors of CBS were self-reported health issues, especially diabetes, and fewer trips into the community. Very few respondents reported receiving any information on CBS from eye care providers. This suggests that doctors should consider discussing CBS with patients, and that both social workers and doctors need a better understanding of CBS, as symptoms could easily be mistaken for mental illness, causing inappropriate referrals.
13

Roy, Sylvain. "Face processing in children with fragile X syndrome : an ERP feasibility study." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=98579.

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Faces provide important information necessary for social communication. The current study aimed to evaluate Event-Related Brain Potentials (ERPs) as a method of exploring face processing abilities in fragile X syndrome (FXS), a genetic disorder where social deficits lie at the core of the cognitive phenotype. Neural changes were investigated in three children with FXS across various conditions such as upright vs. inverted faces, intact faces vs. faces with no eyes as well as faces vs. cars. Relative to chronological age matched controls, children with FXS displayed greater N170 amplitudes and shorter latency peaks across conditions. In addition, the FXS group showed right hemispheric specialization for both face and non-face stimuli. Heightened electrophysiological responses in FXS are discussed in the context of reported hyper-sensitivity and arousal.
14

Kogan, Cary Samuel. "Visual processing deficits in the Fragile X Syndrome." Thesis, McGill University, 2005. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=85927.

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A series of empirical studies is presented that examine the contribution of Fragile X Mental Retardation 1 (FMR1) gene expression to the structure and function of the visual system. This contribution is documented using a histological approach in human and nonhuman primate tissue in conjunction with psychophysical testing of Fragile X Syndrome affected patients who are lacking FMR1 expression.
In the first set of experiments, immunohistological studies of unaffected human and primate brain tissue were carried out to reveal the staining pattern for Fragile X Mental Retardation Protein (FMRP), the protein product of the FMR1 gene, within the two main subcortical pathways at the level of the lateral geniculate nucleus (LGN). FMRP is expressed in significantly greater quantity within the magnocellular (M) neurons of the LGN when compared to levels obtained from the parvocellular (P) neurons. This finding suggests that M neurons depend on FMRP to greater extent than P neurons for determining their normal structure and function. A subsequent histological analysis of the LGN from a FXS affected individual revealed atypical LGN composed of small-sized neurons that were more P- than M-like. This result supports the notion that with the lack of FMR1 expression as occurs in FXS, the impact is greatest to M neuron morphology.
A second set of experiments explored the idea that the M neuron pathology in FXS results in a functional deficit for processing of visual information carried by this pathway. Detection thresholds for stimuli known to probe either M or P-pathway integrity were obtained from individuals affected by FXS as well as age- and developmental-matched control participants. In support of this hypothesis, FXS affected individuals displayed significantly elevated thresholds for M-but not P-specific achromatic visual stimuli. The selectivity of this deficit was verified in a consequent experiment that evaluated colour vision, a visual attribute known to be exclusively processed by the P-pathway. Affected individuals did not differ significantly from developmental-matched control participants in their ability to detect chromatic stimuli. Finally, the effect of the M pathway deficit on cortical visual function was assessed. Results of these experiments reveal that the thresholds for detection of coherent motion, but not form, are significantly elevated in the FXS group. This finding suggests that the parietal (dorsal) visual stream, the major cortical recipient of input from the M pathway, is detrimentally affected in FXS.
A third experiment examines the extent to which the M pathway deficit impacts on cortical visual functioning by employing stimuli of varying complexity that probe the parietal (dorsal) and temporal (ventral) visual streams separately. Results suggest that FXS affected individuals have a pervasive deficit in their ability to detect both simple and more complex forms of motion. In contrast, these same individuals have normal detection thresholds for simple form stimuli. However, with more complex form stimuli affected individuals have significant elevations in threshold. Taken together these results support the notion that the M pathway deficit is amplified at higher levels of visual processing and further, that FXS affected individuals have difficulties integrating all early visual information.
15

Li, Zeyu, and 黎泽宇. "Literature review on children myopia." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45173151.

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16

Candido, Jacqueline P. Haslam Elizabeth L. "Visual impairment in a visual medium perspectives of online learners with visual impairments /." Philadelphia, Pa. : Drexel University, 2008. http://hdl.handle.net/1860/2932.

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17

Davis, Craig A. "Psychosocial adjustment to age-related vision loss." Thesis, Queensland University of Technology, 1992. https://eprints.qut.edu.au/36809/1/T%28HS%29%2086_Digitised%20Thesis.pdf.

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Both the number and proportion of the elderly and people with chronic disability are increasing as a proportion of the entire population, particularly in the over 80 years age range. The most common cause of chronic visual disability in the elderly is age-related maculopathy (ARM). Chronic visual disability, manifested as functional limitations of activities of daily living, often results in psychosocial handicap due to ineffective coping skills. Both low vision services and low vision research have previously been oriented toward functional adjustment to disability, rather than psychosocial aspects of vision loss. Previous disability research has sought to explain psychosocial adjustment in terms of mediators of stress, such as involved in "stress and coping" theory. Recent research interest in measures of rehabilitation outcome have used psychosocial factors as key indicators of adjustment. This study investigates both mediators and measures of psychosocial adjustment to chronic vision loss using a modified stress and coping model. The study consisted of two groups: thirty elderly people with vision loss due to age-related maculopathy (ARM), and thirty elderly people (controls), age-matched and sex-matched to the ARM group but with normal vision. Data were collected, in an interview format in subjects' homes, on four psychosocial scales (life satisfaction, daily hassles, social support, and self-esteem) and a measure of self-care. In addition, information on history of visual impairment, use of optical devices, use of rehabilitation resources, distance and near visual acuity, and demographic factors were also collected. In terms of the model presented, psychosocial results confirmed several, but not all relationships defined within the model and it appears to serve as a useful framework with which to understand the mediating factors in psychosocial adjustment to age-related vision loss. The results tend to suggest that people with chronic age-related vision loss report poorer psychosocial adjustment (as indicated by significantly poorer life satisfaction and greater stress) than age- and sex-matched controls, perhaps as a result of poorer perceptions of social support, despite rehabilitative attention. Several results have implications for the functional rehabilitation of ARM. ARM subjects were found to have significantly poorer mobility and fewer daily activities than control subjects. Reading, recognised as important for both survival and recreational activities for many people with ARM, requires regular follow-up, as indicated by results showing gradual deterioration in vision in the ARM group being associated with poor satisfaction with prescribed reading devices, despite the majority of subjects still using the device daily. People with ARM would therefore seem to prefer to persevere with a coping strategy that is unsatisfactory in order to retain some independence in functioning. Despite several of the individual psychosocial measures used demonstrating their usefulness as measures of psychosocial adjustment, the validity of each of the measures used is questioned. Although the methodology herein does not allow interpretation as to predictors of psychosocial adjustment following onset of vision loss (or indeed following rehabilitation services), interpretation can be made regarding factors important in the adjustment process and inter-relationships between factors. From a clinical perspective therefore, results indicate that effective low vision rehabilitation should include programs that incorporate both psychosocial adjustment and functional adjustment services. Future research is recommended to develop new measures of psychosocial adjustment to age-related vision loss.
18

Rueff, Erin. "Contact lens induced dry eye and binocular vision disorders: A study of similar symptoms." The Ohio State University, 2014. http://rave.ohiolink.edu/etdc/view?acc_num=osu1397167126.

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19

Hancock, Sherri Rosemary McDonald. "An examination of age-related changes in achromatic and chromatic retinal increment thresholds at photopic levels." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/29765.

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This research investigated the influence of the normal aging process on truly photopic achromatic and chromatic retinal increment threshold over an extensive range of colored targets. It was found that for both achromatic and chromatic retinal thresholds there is a significant correlation between advancing age and the stimulus luminance intensity at threshold across the visible spectrum. This correlation is greater for the short wavelength range than for both the middle and the long wavelength ranges (r² (achromatic)= 0.43; r²(chromatic) = 0.49. In addition, a small exploratory study was completed which examined the role of prereceptoral changes in these age-related differences in color vision function. Results from this preliminary study (Experiment II) support the supposition that prereceptoral factors cannot account for all of the age-related losses that are seen in visual function, particularly in the middle and long wavelength ranges of the visible spectrum.
Arts, Faculty of
Psychology, Department of
Graduate
20

Niehorster, Diederick Christian. "Influence of hemianopic visual field loss on motor control." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B45861699.

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21

Patel, Reshma. "Physical and transcriptional mapping studies within the retinitis pigmentosa critical region on chromosome 7p." Thesis, University College London (University of London), 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312179.

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22

Shepherd, Ashley J. "Development of the visual evoked potential in high and low risk preterm infants." Thesis, Glasgow Caledonian University, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388295.

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23

Tulloch, Deborah. "Object permanence and expressive language skills in visually typical, visually atypical and down syndrome infants /." Access Digital Full Text version, 1985. http://pocketknowledge.tc.columbia.edu/home.php/bybib/10579928.

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24

Ng, Siu-chun Danny, and 吳兆駿. "The prevalence of refractive error and visual impairment caused by uncorrected refractive error in China." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2010. http://hub.hku.hk/bib/B4804331X.

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Purpose: WHO reports 46% of world vision impairment from refractive error (RE) among children occurs in China. We estimated RE prevalence and associated vision impairment (VI) among Chinese children and adults. Methods: Data from population-based studies were stratified by gender in age intervals of 3 years (ages 3-17 y) or 10 years (ages >= 30 y): counts of persons with myopia (worse eye spherical equivalent <= -1.0D, <= -2.0D, <= -6.0D) and prevalence of low vision (< 6/12 in the better-seeing eye for children and < 6/18 for adults) and blindness (<=6/60) attributable to RE. Figures for VI included persons with habitual vision below the cutoff improving to above the cutoff with refraction, and those with myopic retinopathy. Estimates for ages 18-29 y were obtained from regression models derived from the pooled estimates. Prevalence of myopia and VI attributable to RE in each age/gender category was calculated by applying modeled rates to 2000 China census figures and projections for 2020. Association with VI attributable to RE was tested for: gender, urban versus rural residence, and residence in provinces with per capita GDP in the upper versus lower 50% for China. Results: Data were obtained from 5 cohorts for children and 14 for adults. There were 291 million and 21.4 million persons with myopia <= -1.0D and <= -6.0D respectively in 2000, expected to rise to 306 million and 36.9 million by 2020. Of these, 18.4 million were blind and 116 million had low vision in 2000, with figures of 25.3 million and 123 million in 2020. Children accounted for the following proportion of RE disease burden in China in 2000: myopia <= -1.0D: 19.0%; RE-associated low vision: 56.1%; blindness: 14.1%. Refractive error was responsible for 82.3% of blindness and 90.5% of low vision among children, and 11.6% and 64.4% of blindness and low vision among adults. Urban residence (OR 1.85, P = 0.004) and higher GDP (OR 10.6, P < 0.001) were associated with refractive blindness among children. For adults, lower GDP was associated with refractive blindness (OR 1.47, P = 0.01). Gender was un-associated with refractive blindness among children or adults. Conclusions: Both children and adults suffer a heavy burden of VI associated with RE in China. Income may affect risk for such VI differently among children and adults.
published_or_final_version
Public Health
Master
Master of Public Health
25

Silver, Byron D., and University of Lethbridge Faculty of Arts and Science. "A transient period for enabling motion vision precedes the critical period for ocular dominance plasticity." Thesis, Lethbridge, Alta. : University of Lethbridge, Faculty of Arts and Science, 2005, 2005. http://hdl.handle.net/10133/287.

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The premise that mature visual function depends upon the nature of visual experience during development is based primarily on experiments showing that visual deprivation during a 'critical' period early in life causes abnormalities in visual cortex and an enduring loss of spatial vision (amplyopia). There is, however, little evidence that early visual experience atually enables mature vision. Experments in this thesis provide such evidence. The measurement of optomotor responses daily from eye opening permanently enhances optomotor sensitivity and the perception of visual motion. The plasticity allowing this enhancement is transient and peaks in efficacy before the start of the classical 'critical ' period for ocular dominance plasticity. The enhancement is dependent upon optomotor responses generated by the movement of high spatial frequency visual stimuli, and is mediated by the visual cortex. These studies show that a form of experience-dependent plasticity, distinct from that of the critical period, enables mature motion vision.
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26

Otters, Rosalie V. "Vision Impairment and Depression in the Older Adult." Thesis, University of North Texas, 2005. https://digital.library.unt.edu/ark:/67531/metadc4848/.

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The older adult population in the United States is rapidly expanding both because of longer life expectancies as well as the aging of the baby boomers. While vision impairment is a growing concern among older adults, there have been few, mostly small studies, of the impact of vision impairment on this population. The present study uses a national data set, the Second Supplement on Aging (1994 -1996) from the National Health Interview Survey, in a cross-sectional study of 9,447 civilian non-institutionalized persons, aged 70 years and over at the time of their interview. The SOA II has been studied in the context of a social theory of aging that emphasizes interdependence through the life course using a stress process model that has been refined into a disability model. Disability is understood as a social construction outcome rather than as a medical outcome. Vision impairment is the stressor which is mediated by health (falls, functioning and self-health report), financial resources (education, income and having only public health insurance) and social support (marital, living along, having no living children, social activities in number and intensity). Depression is a possible, but not a necessary result of vision impairment. Disability may result when a medical pathology leads to an impairment which results in a functional limitation and finally a social disability. This secondary analysis used a multinomial logistic regression for both the whole sample as well as separately for each gender. For the whole sample the results indicate that a typical profile of a vision-impaired older adult depressed some/all of the time, would be a younger-old White woman (aged 70-74 years old) who has fallen in the past 12 months, has difficult with one or more Activities of Daily Living or with both one or more Activities of Daily Living and Instrumental Activities of Daily Living, has a poor to fair self-heath report, a family income under $20,000, a high school or less education, lives alone, has a living child and lacks social activities in number and intensity. In the gender samples, only the female sample at the some/all of the time depression category is significant. Older vision-impaired adults, especially older women who have more social supports are less likely to be depressed and so disabled. There is a need for social policies that will educate, encourage and support older vision-impaired adults as they seek to compensate for the loss of vision, often late in life.
27

Van, Wyk Andoret. "The effect of visual scanning exercises integrated into task-specific activities on the functional ability in patients with visual perceptual disorders post stroke." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/28672.

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Stroke is the first cause of disability and second most frequent cause of mortality after ischemic heart disease in adults worldwide. The influence of visual system impairment on the patient’s functional ability and quality of life are still largely neglected in neurological rehabilitation. Therapists are seldom concerned with the visual status and ability of their patients. Members of the rehabilitation team rarely assess, monitor or treat impairment of visual efficiency processes and visual information processing dysfunction that may be observed in patients after a stroke. In the absence of specific intervention visual deficits stabilise and become permanent due to poor or almost absent spontaneous recovery of the visual system in stroke patients. A matched-pair randomised controlled trial was conducted. Twenty-four (24) participants were screened based on their functional activity level as measured on the Stroke Activity Scale (SAS). When a participant’s SAS score matched a previously allocated participant’s score, that particular participant was placed in the opposite group from the existing matched participant. If the newly assessed participant’s SAS did not match another participant’s SAS, the participant was randomly allocated to either the experimental or the control group. The process was repeated until (24) patients had been allocated into two groups consisting of twelve (12) participants per group as they were admitted to Tshwane Rehabilitation Centre (TRC). Group 1 (Experimental Group) received saccadic eye movement training with visual scanning exercises integrated with task-specific activities and Group 2 (Control Group) received task-specific activities for four (4) consecutive weeks. Participants functional progress on body impairment and functional activity level were assessed and documented on a weekly basis during the intervention period of four (4) weeks. In order to determine whether the integration of visual scanning through saccadic eye movement training had a permanent or long-term effect on the participants’ functional ability and quality of life after rehabilitation had been terminated, functional progress on body impairment-, functional activity and participation levels as well as their perceived quality of life were assessed and documented eight (8), twelve (12), sixteen (16) and twenty (20) weeks after admission to the rehabilitation facility. A large number of participants were lost to follow-up following discharge from the TRC after the intervention period of four (4) weeks. As result of the small sample group at week eight (8), week twelve (12), week sixteen (16) and week twenty (20), these results were not discussed. Results of the matched-pair randomised controlled trial indicated that the effect of saccadic eye movement training with visual scanning exercises integrated with task specific activities as an intervention for participants that presented with unilateral spatial inattention, visual-spatial disorders and visual-constructive disorders poststroke resulted in significant improvement in impairment level. This improvement related to oculomotor visual performance, visual attention, depression as well as results on functional activity level with regard to the ability to independently complete ADL after four (4) weeks of rehabilitation. It may therefore be concluded that saccadic eye movement training with visual scanning exercises integrated with task-specific activities as an intervention tend to improve functional ability in participants that presented with unilateral spatial inattention, visual-spatial disorders and visual-constructive disorders post-stroke.
Dissertation (MPhysT)--University of Pretoria, 2013.
Physiotherapy
unrestricted
28

Pai, Amy Shih-I. "Vision and refraction in Australian preschool children : measures, prevalence, and associated factors." Phd thesis, Faculty of Medicine, 2013. http://hdl.handle.net/2123/10045.

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29

Herring, Mathew Peter. "A strategic management framework for eye care service delivery organisations in developing countries." Title page, abstract and table of contents only, 2004. http://thesis.library.adelaide.edu.au/public/adt-SUA20050420.125947/index.html.

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Thesis (Ph.D.)--University of Adelaide, School of History and Politics, Discipline of Politics, 2004.
Title from opening screen; viewed 19 May 2005. "August 2004." Includes bibliographical references. Also available in print format.
30

Anderson, Krista K. "A multidimensional analysis of body image among women with and without a visual impairment /." free to MU campus, to others for purchase, 1997. http://wwwlib.umi.com/cr/mo/fullcit?p9841129.

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31

Lassiter, Donald L. "The effects of transient adaptation in simulated VDT operations." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/28761.

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32

Vivier, Yolande. "Spelterapeutiese assessering van die adolessent met gesiggestremdheid in institusionele verband se verhouding met sy gesin." Pretoria : [s.n.], 2003. http://upetd.up.ac.za/thesis/available/etd-02252005-115702.

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33

Cherepanoff, Svetlana. "Age-related macular degeneration histopathological and serum autoantibody studies /." Connect to full text, 2007. http://hdl.handle.net/2123/2464.

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Thesis (Ph. D.)--University of Sydney, 2008.
Title from title screen (viewed 18 June 2008). Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Department of Clinical Ophthalmology and Eye Health, Faculty of Medicine. Degree awarded 2008; thesis submitted 2007. Includes bibliographical references. Also available in print form.
34

Vongphanit, Jerry. "Ocular effects and impact of myopia and astigmatism in an older population." Thesis, The University of Sydney, 2002. https://hdl.handle.net/2123/27836.

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Purpose To assess the relationship between corrected refractive errors and the degree of visual impairment, and determine the prevalence of myopic retinopathy and tilted discs in subjects attending the Blue Mountains Eye Study. Methods The Blue Mountains Eye Study is a population—based cohort of urban Australians aged 49 or older. Of the 4433 eligible persons, 3654 (82.4%) participated in the study between 1992—4 (BMES I). Of the 3114 living eligible participants from BMES I, 2334 (75.0%) were reexamined between 1997—9 (BMES H). The ocular examination included logMAR visual acuity, standardised refraction, applanation tonometry, cover testing, stereoscopic retinal photographs and Humphrey visual field testing. Retinal signs adjudicated included posterior staphyloma, lacquer cracks, Fuchs’ spot, myopic chorioretinal thinning and atrophy, Bperipapillary atrophy and tilted optic discs. Visual impairment was defined as best-corrected visual acuity of 20/40 or worse.
35

Zwan, Rick van der. "Possible neural substrates for binocular rivalry." Thesis, The University of Sydney, 1994. https://hdl.handle.net/2123/28543.

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Binocular rivalry is the perceptual consequence of dichoptic input which is not congruent between both visual inputs. There is some evidence, both theoretical and empirical, that the perception of binocular rivalry is mediated by interactions between binocular neurones, rather than by interactions between monocular neurones. This evidence suggests also a model of perception which predicts binocular rivalry as a consequence of normal interactions between binocular neurones in a retinotopic array. This model accounts for rivalry without postulating any additional interconnections beyond those already thought to exist between binocular neurones simply assumes an orderly mapping of tuning characteristics across groups of cells, as is typically observed in visual cortex. On the basis of this model, and findings already reported, it was hypothesised that binocular rivalry reflects extrastriate rather than area V1 processing (no process so far attributed to area V1 has yet been reported to be affected by binocular rivalry). It was hypothesised also that area V2 was the most likely area in which such processing first arises. Area V2 has been associated with the perception of 'purely subjective contours'. It has been shown that some cells in area V2 are tuned for such contours, which are characterised by the absence of Fourier components at the orientation of the perceived contour, while no cells in area V1 have been found to be similarly sensitive (von der Heydt and Peterhans 1989). This characteristic of area V2 neurones enables purely subjective contours to be used to test the two hypotheses described above. Real contour tilt aftereffects, which are thought to arise in area V1, are not affected by rivalry during their induction. If purely subjective contour tilt aftereffects (Paradiso, Shimojo and Nakayama 1989) are subject to the same types of processing as their real contour counterparts, as suggested by the rationale and model of von der Heydt and Peterhans (1989), interactions between subjective contour tilt aftereffects and binocular rivalry should indicate the role, if any, of area V2 in rivalry. It was found that purely subjective contour tilt aftereffects (Experiment One) and tilt illusions (Experiment Four) exhibit angular functions like those observed for real contour tilt aftereffects and illusions. Just as for real contour effects, these functions can be described in terms of direct effects (Experiment Two) and indirect effects (Experiment Three), suggesting purely subjective contours are processed as if they were real contours. Unlike real contour direct effects, purely subjective contour direct and indirect effects are reduced in magnitude by periods of rivalry during their induction (Experiment Five). In keeping with their suggested extrastriate locus (eg. Wenderoth, van der Zwan and Williams 1993), the magnitude of a real contour indirect effect is also reduced by periods of rivalry occurring during its induction (Experiment Six). These results suggest that rivalry does arise first in area V2. If this is true then complete interocular transfer of the purely subjective aftereffect, induced with or without rivalry, should occur because area V2 is almost exclusively binocular. This proved not to be the case, however, suggesting the ocular dominance observed in most binocular cells has to be taken into account in any explanation of rivalry (Experiment Seven). This was tested using real contours and found to be the case. These last results suggested also that rivalrous interactions occur between groups of binocular neurones only in extrastriate cortex (Experiment Eight). This hypothesis was tested by examining the effect of binocular rivalry on the duration of the plaid motion aftereffect, which is thought to arise no earlier than area MT, a visual cortical area which is also thought to be almost exclusively binocular. It was found that rivalry did reduce the duration of plaid motion aftereffects but not linear motion aftereffects, and that the impact of rivalry might be linked to plaid sensitive cells in area MT, although this last conclusion is tenuous (Experiments Nine and Ten). Finally, it was shown also that the magnitude of the reduction in duration of the aftereffect was proportional to the predominance of the plaid stimulus during rivalry, a finding which supports the mechanism of rivalry suggested by the binocular model. The results together suggest that binocular rivalry does arise through binocular interactions, but that such interactions cannot be attributed to a single cortical area. All groups of binocular neurones may be subject to the processes that ultimately give rise to the perception of rivalry, a conclusion which does not invalidate the binocular model of rivalry. This has some consequences for binocular vision, particularly stereopsis, which might occur qualitatively during binocular rivalry.
36

Wang, Chongwen, and 汪崇文. "The impacts of psycho-social-spiritual factors on health-related quality of life among Chinese older adults with visual problems." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2006. http://hub.hku.hk/bib/B37044394.

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37

Ali, Mohammed Irshad. "A job search skills curriculum for individuals with visual disabilities in Fiji." CSUSB ScholarWorks, 1993. https://scholarworks.lib.csusb.edu/etd-project/796.

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38

Hall, Heather Lynne. "Early teller acuity card estimates as predictors of long-term visual outcome in children with perinatal complications." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp01/MQ55507.pdf.

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39

Riddell, Patricia Mary. "Vergence eye movements and dyslexia." Thesis, University of Oxford, 1987. http://ora.ox.ac.uk/objects/uuid:fc695d53-073a-467d-bc8d-8d47c0b9321e.

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40

Singer, Harris Naomi. "Relationship between degree of neuroanatomic abnormality and visual orienting deficits in young children with autism /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 1997. http://wwwlib.umi.com/cr/ucsd/fullcit?p9804534.

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41

Teär, Fahnehjelm Kristina. "Posterior ocular malformations in children : teratological aspects /." Stockholm, 2003. http://diss.kib.ki.se/2003/91-7349-470-4.

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42

Kish, Charles Daniel. "Evaluation of an echo-mobility program for young blind people." CSUSB ScholarWorks, 1995. https://scholarworks.lib.csusb.edu/etd-project/1036.

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43

Mumford, Ceris. "Coloured filters and literacy progress." Thesis, University of Oxford, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.572655.

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~ ..•.. There are two types of Oxford Filter; blue filters enhance short wavelength light and yel,low enhance long wavelength light. These filters have previously been shown to improve reading performance, vergence eye movements and perception of visual form and motion. In this thesis the effects of such filters were examined in both an unselected primary school population, and in a clinical population of children with identified visual and/or reading difficulties. A school based visual screening study established that just over 40% of children identified a filter as beneficial when viewing text. These children reported a significantly higher number of visual symptoms and had significantly reduced convergence and accommodation eye movements compared to non-filter choosers. A further trial of filter use revealed that those using blue filters made significant improvements in accommodative function and in spelling ability. A cross-over, randomised controlled trial was conducted in the clinical sample with psychometric, orthoptic and psychophysical assessments administered before and after filter use. Poor readers made significant improvements in reading following filter use, but a smaller dyslexic group were not found to improve their reading. Performance on a Matrices task significantly improved after using yellow filters specifically. There was also evidence that children with reduced saccades improved their spelling with the use of yellow filters, but had reduced spelling following blue use. Although filters impacted upon both orthoptic and literacy measures these improvements appear not to be causally linked. A random dot kinematogram task (RDK) revealed a correlation between magnocellular functioning under blue and yellow lighting conditions and reading; lower reading was associated with poorer RDK thresholds. This association was specific to reading and not evident in relation to dyslexia. Visual search accuracy was also shown to improve significantly after the use of blue and yellow filters. Together these findings have implications for the treatment of orthoptic abnormalities and literacy performance.
44

Costa, Marcelo Fernandes da. "Perdas de função visual na distrofia muscular de Duchenne: visão de cores e visão de contrastes de luminância temporal e espacial." Universidade de São Paulo, 2004. http://www.teses.usp.br/teses/disponiveis/47/47135/tde-02102006-112028/.

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A Distrofia Muscular de Duchenne (DMD) é uma doença recessiva ligada ao cromossomo X, causada por deleção ou mutação na proteína distrofina, e afeta 1 para cada 3.500 nascidos vivos do sexo masculino. O gene da distrofina é o maior gene do genoma humano e, além das proteínas de tamanho total, ao menos outras 5 isoformas foram identificadas até o momento. A isoforma total da distrofina e outras menores como a Dp260 (transcrita pelo promotor localizado no exon 30; encontrada na camada plexiforme externa da retina) e Dp71 (transcrita pelo promotor localizado no exon 63; encontrada nas células de Muller e membrana limitante interna da retina) são expressas na retina, dentre vários tecidos do corpo. Alterações nos eletrorretinogramas (ERG) de sujeitos com DMD já foram descritas na literatura. Redução da amplitude da onda-b e ERG negativo (razão das.amplitudes entre as ondas b e a menor que 1) são os achados mais comuns principalmente em sujeitos com deleção posterior ao exon 30. Embora estas alterações sejam conhecidas, poucos estudos avaliaram funcionalmente a visão destes sujeitos e, estes concluíram que os sujeitos com DMD apresentam visão de cores, acuidade visual e motilidade ocular normais. Como estas conclusões não refletem os achados eletrofisiológicos, o presente trabalho teve por objetivo aprofundar a avaliação de funções visuais em sujeitos com DMD, utilizando testes psicofisicos mais precisos e sensíveis que os métodos anteriormente empregados. Aplicamos uma bateria de testes que avaliou: a visão de cores (Cambridge Colour Test, Anomaloscópio de Neitz tipo I, lshihara e AO H-R-R) e a sensibilidade ao contraste de luminância (espacial e temporal), em 54 meninos (idade média =14,2 ± 4,1) com DMD, bem como o ERG em um subgrupo de 11 sujeitos. De acordo com a região da deleção no gene foram constituídos 3 grupos: grupo 1 (n=20) - sem deleção, grupo 2 (n=7) - com deleção anterior ao exon 30, grupo 3 (n=27) com deleção posterior ao exon 30. O grupo controle foi composto por 35 meninos com idade equiparada (médias = 15,4 ± 3,9). Os resultados mostraram que 52% dos sujeitos do grupo 3 apresentam defeitos de visão de cores. Surpreendentemente, a maioria destes sujeitos apresentou um defeito no eixo protan-deutan. Os três grupos apresentaram redução na sensibilidade ao contraste espacial e ao contraste temporal para todas as freqüências espaciais e temporais testadas. Houve uma tendência do grupo 3 de ter os piores resultados de contraste espacial. Para os resultados de contraste temporal, diferiram estatisticamente do grupo controle apenas os sujeitos do grupo 3 que tinham defeito de visão de cores. Os parâmetros do ERG de campo total replicaram os dados da literatura mostrando uma diminuição da amplitude e um aumento da latência da onda-b, além de uma razão b/a menor que l. A análise individual dos potenciais oscilatórios mostrou redução significante no 3° e no 4° potenciais, indicando que tanto a via dos cones quanto a dos bastonetes estão afetadas nos sujeitos com.DMD e deleção posterior ao exon 30. A constatação das maiores alterações de função visual nos sujeitos com deleção posterior ao exon 30 leva a sugerir que a distrofina Dp260 tem papel importante na fisiologia retiniana. Em conclusão, o presente trabalho demonstrou que a DMD é acompanhada por perdas visuais em várias funções e que estas perdas podem ser causadas principalmente por modificações na isoforma Dp260 da distrofina
Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder, caused by deletion or mutation in the protein dystrophyn, which affects 1:3500 live male births. The dystrophyn gene is the largest gene in the human genome. The full-length dystrophyn and at least other 5 isoforms have been identified. They are expressed in several tissues of the body including the retina, where the shorter isoforms Dp260 (transcribed by a promoter at the exon 30; founded in the outer plexiform layer of the retina) and Dp71 (transcribed by a promoter at the exon 63; founded in the Muller cells and inner limiting membrane of the retina) have been shown. Alterations in the electroretinograms (ERG) of these subjects have been described in the literature. 13-wave amplitude reduction and -a negative ERG (b/a wave amplitude ratio < 1) are the most common alterations found in subjects with gene deletion downstream exon 30, transcribes Dp260 isoform. Although these alterations are known, the only study that performed 1 evaluations of visual functions in these subjects concluded that they showed normal color vision, visual acuity and ocular motility results. Since these conclusions do not reflect the electrophysiological findings the objective of the present study was to further evaluate the visual function of DMD subjects using more sensitive and precise psychophysical tests than the methods used before. A battery of visual tests was used to evaluate color vision (Cambridge Colour Test, Neitz-1 Anomaloscope, Ishihara and AO H-R-R), luminance contrast sensitivity (spatial and temporal) in 54 boys (mean age = 14,2 ± 4,1) with DMD, and the ERG was also measured in a subgroup (n = 11) of these boys. According with the region of gene deletion, the subjects were divided in 3 groups: group 1 (n = 20) - without gene deletion, group 2 (n = 7) - with gene deletion upstream exon 30, group 3 (n = 27) - with gene deletion downstream exon 30. The control group was composed of 35 age-matched boys (mean-- 15,4 ± 3,9). Our results showed that 52% of the group 3 subjects had color vision defects. Surprisingly, almost all of these boys had a defect in the proten-deutan axis. In all three groups, spatial and temporal contrast sensitivities were lower than those of controls, for all spatial and temporal frequencies tested. Group 3 subjects had a tendency not statistically significant to present the worst results of spatial contrast sensitivities. Temporal contrast sensitivities were significantly different from controls' only for group 3 subjects with color vision defects. The full-field ERG results showed a b-wave amplitude reduction, a longer implicit time and a b/a ratio less than 1. Oscillatory potentials were significantly lower in the 3° and 4° potentials suggesting that that both cone and rod pathways were affected in the DMD subjects with deletion downstream exon 30. To our knowledge there are no descriptions of visual function defects in DMD subjects. The finding that the largest alterationslosses of visual function oceur in the subjects with deletion downstream exon 30 leads us to suggest that the dystrophyn Dp260 has an important role in the physiology of the retina physiology. In conclusion, the present study showed that DMD is accompanied losses in several visual functions and that these losses may be caused mainly by impairment in the Dp260 dystrophyn isoform
45

Lameirinha, Jorge de Almeida. "Importância do rastreio visual precoce nas crianças: impacto nos cuidados de saúde secundários." Master's thesis, Faculdade de Ciências Médicas. Universidade Nova de Lisboa, 2007. http://hdl.handle.net/10362/4847.

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Tendo como ponto de partida os objectivos do Programa Nacional para a Saúde da Visão 2004-2010 relativos à prevenção primária e à detecção precoce das alterações oftalmológicas, a tese de mestrado do Ortoptista Jorge Lameirinha sob o tema “Importância do Rastreio Visual Precoce nas Crianças: Impactos nos Cuidados de Saúde Secundários” procura abrir um campo de reflexão e validação de como é feita a detecção precoce de alterações oftalmológicas e a respectiva referenciação dos cuidados de saúde primários para a consulta de especialidade hospitalar. De forma a enquadrar a saúde visual infantil, identificar a importância da sua vigilância e dos critérios de referenciação de alterações oftalmológicas entre diferentes níveis de cuidados de saúde em Portugal – nível primário e secundário -, considerou-se pertinente para efeitos de investigação proceder-se à análise de um universo circunscrito no tempo e no espaço. Esta investigação parte da observação e análise de (1) um universo de 845 crianças com idades compreendidas entre os 0 e os 14 anos que realizaram um rastreio visual na consulta de oftalmologia pediátrica do Hospital de São Bernardo – Centro Hospitalar de Setúbal -, e (2) dos resultados de um inquérito por questionário acerca de como é desenvolvida a vigilância visual infantil, aplicado aos Directores dos Centros de Saúde do Concelho de Setúbal. Da apresentação e discussão dos principais resultados, este estudo traz algumas recomendações para a resolução de determinados bloqueios, identificados na realização do rastreio visual infantil, e propostas para reforçar a implementação das directivas expostas no Programa Nacional para a Saúde Visual.
46

Wong, James Gilbert. "Immunological and inflammatory aspects of age-related macular degeneration measured by quantitative immunohistochemical techniques." Master's thesis, Sydney Medical School, 2004. http://hdl.handle.net/2123/14167.

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47

Sandlund, Jonas. "Position-matching and goal-directed reaching acuity of the upper limb in chronic neck pain : associations to self-rated characteristics." Doctoral thesis, Umeå : Gävle : Univ. ; Centre for Musculoskeletal Research, University of Gävle, 2008. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-1635.

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48

Gitchel, George Thomas Jr. "Development of an Accurate Differential Diagnostic Tool for Neurological Movement Disorders Utilizing Eye Movements." VCU Scholars Compass, 2015. http://scholarscompass.vcu.edu/etd/4109.

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Parkinson’s disease and Essential tremor are the two most prevalent movement disorders in the world, but due to overlapping clinical symptoms, accurate differential diagnosis is difficult. As a result, approximately 60% of patients with movement disorders symptoms will have their diagnosis changed at least once before death. By their subjective nature, clinical exams are inherently imprecise, leading to the desire to create an objective, quantifiable test for movement disorders; a test that currently is elusive. Eye movements have been studied for a century, and are widely appreciated to be quantifiably affected in those with neurological disease. Through a collaborative effort between the VA hospital and VCU, over 1,000 movement disorder subjects had their eye movements recorded, utilizing an SR Research Eyelink 2. Patients with Parkinson’s disease exhibited an ocular gaze tremor during fixation, normal reflexive saccades, and reduced blink rate. Subjects with Essential tremor exhibited slowed saccadic dynamics, with increased latencies, in addition to a larger number of square wave jerk interruptions of otherwise stable fixation. After diagnostic features of each disorder were identified, prospective data collection could occur in a blinded fashion, and oculomotor features used to predict clinical diagnoses. It was determined that measures of fixation stability were capable of almost perfectly differentiating subjects with PD, and a novel, combined parameter was capable of similar results in ET. As a group, it appears as if these symptoms do not progress as the disease does, but subanalyses show that individual patients on constant pharmaceutical doses tracked over time do slightly change and progress. The near perfect separation of disease states suggest the ability of oculomotor recording to be a powerful biomarker to be used for the differential diagnosis of movement disorders. This tool could potentially impact and improve the lives of millions of people the world over.
49

Van, Epps Heather Alane. "Insights from the characterization and cloning of the zebrafish visual mutant, nrc : synaptojanin's essential role in photoreceptor ribbon synaptic function /." Thesis, Connect to this title online; UW restricted, 2004. http://hdl.handle.net/1773/9205.

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50

Papečkytė, Jolita. "X gimnazijos pirmų ir ketvirtų klasių moksleivių sveikatos sutrikimų ir darbo kompiuteriu sąsajos." Master's thesis, Lithuanian Academic Libraries Network (LABT), 2008. http://vddb.library.lt/obj/LT-eLABa-0001:E.02~2008~D_20080616_134444-36162.

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Darbo tikslas. Įvertinti darbo kompiuteriu ir vaikų sveikatos pakenkimų sąsajas. Uždaviniai: 1.Ištirti regėjimo funkcijos sutrikimų, netaisyklingos laikysenos ir skoliozių dinamiką; 2.Nustatyti sveikatos sutrikimų/nusiskundimų (regos ir kaulų - raumenų sistemos) ir darbo kompiuteriu sąsajas; 3.Įvertinti moksleivių darbą kompiuteriu namuose ir jo aplinką. Tyrimo metodika. Tyrimas buvo atliktas 2006 - 2008 metais. Tyrime dalyvavo 428 Kauno X gimnazijos pirmų ir ketvirtų klasių moksleiviai, atsako dažnis 92.24 proc. Duomenys rinkti iš medicininių dokumentų ir anketinės apklausos būdu. Statistinė duomenų analizė atlikta naudojant kompiuterinį SPSS 13.0 statistinį paketą ir MS Excel. Rezultatai. Nustatyta, kad apie 40 proc. vaikų turi regėjimo ir 33 proc. kaulų - raumenų sutrikimus. Nustatyta statistiškai patikimas regėjimo aštrumo blogėjimas ir didėjantis moksleivių skoliozių dažnis. Pagrindiniai regėjimo sutrikimai dirbant kompiuteriu yra: 42,3 proc. akių skausmas, 38,6 proc. akių paraudimas, 32,9 proc. pablogėjęs matymas, 26,2 proc. ašarojimas, 23,8 proc. akių džiūvimas, 19,6 proc. mirgėjimas akyse. Nustatytas ryšys tarp valandų praleistų prie kompiuterio ir regėjimo aštrumo mažėjimo. Dažniausi kaulų - raumenų sutrikimai: 42,3 proc. stuburo, 36 proc. kaklo, 16,8 proc. pečių lanko, 14 proc. riešo, 11 proc. juosmeninės dalies skausmai. Nustatytas ryšys tarp laiko praleisto prie kompiuterio ir juosmeninės dalies skausmo (p=0,033). Mergaitės daugiau laiko praleidžia rašydamos... [toliau žr. visą tekstą]
Aim of the study. The objective of this study is to evaluate correlation between health disorders and work with the computer. Objectives. The goals of this work are to study dynamics of disorders of the function of vision, bad posture, and scoliosis; to establish correlation between health disorders/complaints (sight, bone-muscle system) and work with the computer; to measure students’ work with the computer at home and its environment. Methods. The research was done in 2006-2008; it involved 428 participants of 1ST and 4th form students of X Gymnasium. The percent of frequency of response was 92,24. Data was collected from medical documents and by carrying out a survey. Statistical analysis of data was done using computer-based statistical batch SPSS 13.0 and MS Excel. Results. The results show that 40% of students have vision disorders and 67% - musculosceletal disorders. There is statistical evidence of growth in eyesight worsening and growing frequency of scoliosis among students. The main vision disorders caused by computers include: 42,3% eyestrain, 38,6% red eyes, 32,9% reduced vision, 26,2% running eyes, 23,8% dry eyes, 19,6% flicker. Connection is established between the time spent at a computer and reduced eyesight. Most frequent musculoscelatal disorders include: 42,3% pain in the spinal column; 36% - neck area, 16,8% - shoulder arch, 14% - wrist, 11% - girdle pain. There is relation between time spent at a computer and girdle pain (p=0,033). Girls spend... [to full text]

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