883 resultados para accommodation paralysis
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Purpose This thesis is about liveability, place and ageing in the high density urban landscape of Brisbane, Australia. As with other major developed cities around the globe, Brisbane has adopted policies to increase urban residential densities to meet the main liveability and sustainability aim of decreasing car dependence and therefore pollution, as well as to minimise the loss of greenfield areas and habitats to developers. This objective hinges on urban neighbourhoods/communities being liveable places, which residents do not have to leave for everyday living. Community/neighbourhood liveability is an essential ingredient in healthy ageing in place and has a substantial impact upon the safety, independence and well-being of older adults. It is generally accepted that ageing in place is optimal for both older people and the state. The optimality of ageing in place generally assumes that there is a particular quality to environments or standard of liveability in which people successfully age in place. The aim of this thesis was to examine if there are particular environmental qualities or aspects of liveability that test optimality and to better understand the key liveability factors that contribute to successful ageing in place. Method A strength of this thesis is that it draws on two separate studies to address the research question of what makes high density liveable for older people. In Chapter 3, the two methods are identified and differentiated as Method 1 (used in Paper 1) and Method 2 (used in Papers 2, 3, 4 and 5). Method 1 involved qualitative interviews with 24 inner city high density Brisbane residents. The major strength of this thesis is the innovative methodology outlined in the thesis as Method 2. Method 2 involved a case study approach employing qualitative and quantitative methods. Qualitative data was collected using semi-structured, in-depth interviews and time-use diaries completed by participants during the week of tracking. The quantitative data was gathered using Global Positioning Systems for tracking and Geographical Information Systems for mapping and analysis of participants’ activities. The combination of quantitative and qualitative analysis captured both participants’ subjective perceptions of their neighbourhoods and their patterns of movement. This enhanced understanding of how neighbourhoods and communities function and of the various liveability dimensions that contribute to active ageing and ageing in place for older people living in high density environments. Both studies’ participants were inner-city high density residents of Brisbane. The study based on Method 1 drew on a wider age demographic than the study based on Method 2. Findings The five papers presented in this thesis by publication indicate a complex inter-relationship of the factors that make a place liveable. The first three papers identify what is comparable and different between the physical and social factors of high density communities/neighbourhoods. The last two papers explore relationships between social engagement and broader community variables such as infrastructure and the physical built environments that are risk or protective factors relevant to community liveability, active ageing and ageing in place in high density. The research highlights the importance of creating and/or maintaining a barrier-free environment and liveable community for ageing adults. Together, the papers promote liveability, social engagement and active ageing in high density neighbourhoods by identifying factors that constitute liveability and strategies that foster active ageing and ageing in place, social connections and well-being. Recommendations There is a strong need to offer more support for active ageing and ageing in place. While the data analyses of this research provide insight into the lived experience of high density residents, further research is warranted. Further qualitative and quantitative research is needed to explore in more depth, the urban experience and opinions of older people living in urban environments. In particular, more empirical research and theory-building is needed in order to expand understanding of the particular environmental qualities that enable successful ageing in place in our cities and to guide efforts aimed at meeting this objective. The results suggest that encouraging the presence of more inner city retail outlets, particularly services that are utilised frequently in people’s daily lives such as supermarkets, medical services and pharmacies, would potentially help ensure residents fully engage in their local community. The connectivity of streets, footpaths and their role in facilitating the reaching of destinations are well understood as an important dimension of liveability. To encourage uptake of sustainable transport, the built environment must provide easy, accessible connections between buildings, walkways, cycle paths and public transport nodes. Wider streets, given that they take more time to cross than narrow streets, tend to .compromise safety - especially for older people. Similarly, the width of footpaths, the level of buffering, the presence of trees, lighting, seating and design of and distance between pedestrian crossings significantly affects the pedestrian experience for older people and impacts upon their choice of transportation. High density neighbourhoods also require greater levels of street fixtures and furniture for everyday life to make places more useable and comfortable for regular use. The importance of making the public realm useful and habitable for older people cannot be over-emphasised. Originality/value While older people are attracted to high density settings, there has been little empirical evidence linking liveability satisfaction with older people’s use of urban neighbourhoods. The current study examined the relationships between community/neighbourhood liveability, place and ageing to better understand the implications for those adults who age in place. The five papers presented in this thesis add to the understanding of what high density liveable age-friendly communities/ neighbourhoods are and what makes them so for older Australians. Neighbourhood liveability for older people is about being able to age in place and remain active. Issues of ageing in Australia and other areas of the developed world will become more critical in the coming decades. Creating livable communities for all ages calls for partnerships across all levels of government agencies and among different sectors within communities. The increasing percentage of older people in the community will have increasing political influence and it will be a foolish government who ignores the needs of an older society.
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Purpose: The prevalence of refractive errors in children has been extensively researched. Comparisons between studies can, however, be compromised because of differences between accommodation control methods and techniques used for measuring refractive error. The aim of this study was to compare spherical refractive error results obtained at baseline and using two different accommodation control methods – extended optical fogging and cycloplegia, for two measurement techniques – autorefraction and retinoscopy. Methods: Participants comprised twenty-five school children aged between 6 and 13 years (mean age: 9.52 ± 2.06 years). The refractive error of one eye was measured at baseline and again under two different accommodation control conditions: extended optical fogging (+2.00DS for 20 minutes) and cycloplegia (1% cyclopentolate). Autorefraction and retinoscopy were both used to measure most plus spherical power for each condition. Results: A significant interaction was demonstrated between measurement technique and accommodation control method (p = 0.036), with significant differences in spherical power evident between accommodation control methods for each of the measurement techniques (p < 0.005). For retinoscopy, refractive errors were significantly more positive for cycloplegia compared to optical fogging, which were in turn significantly more positive than baseline, while for autorefraction, there were significant differences between cycloplegia and extended optical fogging and between cycloplegia and baseline only. Conclusions: Determination of refractive error under cycloplegia elicits more plus than using extended optical fogging as a method to relax accommodation. These findings support the use of cycloplegic refraction compared with extended optical fogging as a means of controlling accommodation for population based refractive error studies in children.
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The time course of elongation and recovery of axial length associated with a 30 minute accommodative task was studied using optical low coherence reflectometry in a population of young adult myopic (n = 37) and emmetropic (n = 22) subjects. Ten of the 59 subjects were excluded from analysis either due to inconsistent accommodative response, or incomplete anterior biometry data. Those subjects with valid data (n = 49) were found to exhibit a significant axial elongation immediately following the commencement of a 30 minute, 4 D accommodation task, which was sustained for the duration of the task, and ¬was evident to a lesser extent immediately following task cessation. During the accommodation task, on average, the myopic subjects exhibited 22 ± 34 µm, and the emmetropic subjects 6 ± 22 µm of axial elongation, however the differences in axial elongation between the myopic and emmetropic subjects were not statistically significant (p = 0.136). Immediately following the completion of the task, the myopic subjects still exhibited an axial elongation (mean magnitude 12 ± 28 µm), that was significantly greater (p < 0.05) than the changes in axial length observed in the emmetropic subjects (mean change -3 ± 16 µm). Axial length had returned to baseline levels 10 minutes after completion of the accommodation task. The time for recovery from accommodation-induced axial elongation was greater in myopes, which may reflect differences in the biomechanical properties of the globe associated with refractive error. Changes in subfoveal choroidal thickness were able to be measured in 37 of the 59 subjects, and a small amount of choroidal thinning was observed during the accommodation task that was statistically significant in the myopic subjects (p < 0.05). These subfoveal choroidal changes could account for some but not all of the increased axial length during accommodation.
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The aim of the study was to determine how aspects of communication between nurses and the elderly were perceived by elderly people, future nurses, and uninvolved observers. Respondents (elderly women and nursing and psychology students) rated videotapes of interactions between a nurse and an elderly woman on three dimensions: patronizing, status, and solidarity. Three communication strategies and their combinations were represented in the vignettes. Because the strategies presented were perceived as patronizing by all three groups, no group effect was found for the patronizing dimension. The results show clear group differences particularly between the nursing students and the elderly, with the elderly rating many of the strategies more positively than did the nursing students. The results are discussed in relation to previous evaluations of overaccommodation, and implications of the different perceptions are considered.
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In his 2007 PESA keynote address, Paul Smeyers discussed the increasing regulation of child-rearing through government intervention and the generation of “experts,” citing particular examples from Europe where cases of childhood obesity and parental neglect have stirred public opinion and political debate. In his paper (this issue), Smeyers touches on a number of tensions before concluding that child rearing qualifies as a practice in which liberal governments should be reluctant to intervene. In response, I draw on recent experiences in Australia and argue that certain tragic events of late are the result of an ethical, moral and social vacuum in which these tensions coalesce. While I agree with Smeyers that governments should be reluctant to “intervene” in the private domain of the family, I argue that there is a difference between intervention and support. In concluding, I maintain that if certain Western liberal democracies did a more comprehensive job of supporting children and their families through active social investment in primary school education, then both families and schools would be better equipped to deal with the challenges they now face.
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Purpose: Inaccurate accommodation during nearwork and subsequent accommodative hysteresis may influence myopia development. Myopia is highly prevalent in Singapore; an untested theory is that Chinese children are prone to these accommodation characteristics. We measured the accuracy of accommodation responses during and nearwork-induced transient myopia (NITM) after periods spent reading Chinese and English texts. Methods: Refractions of 40 emmetropic and 43 myopic children were measured with a free-space autorefractor for four reading tasks of 10-minute durations: Chinese (SimSun, 10.5 points) and English (Times New Roman, 12 points) texts at 25 cm and 33 cm. Accuracy was obtained by subtracting accommodation response from accommodation demand. Nearwork-induced transient myopia was obtained by subtracting pretask distance refraction from posttask refraction, and regression was determined as the time for the posttask refraction to return to pretask levels. Results: There were significant, but small, effects of text type (Chinese, 0.97 ± 0.32 diopters [D] vs. English, 1.00 ± 0.37 D; F1,1230 = 7.24, p = 0.007) and reading distance (33 cm, 1.01 ± 0.30 D vs. 25 cm, 0.97 ± 0.39 D; F1,1230 = 7.74, p = 0.005) on accommodation accuracy across all participants. Accuracy was similar for emmetropic and myopic children across all reading tasks. Neither text type nor reading distance had significant effects on NITM or its regression. Myopes had greater NITM (by 0.07 D) (F1,81 = 5.05, p = 0.03) that took longer (by 50s) (F1,81 = 31.08, p < 0.01) to dissipate. Conclusions: Reading Chinese text caused smaller accommodative lags than reading English text, but the small differences were not clinically significant. Myopic children had significantly greater NITM and longer regression than emmetropic children for both texts. Whether differences in NITM are a cause or consequence of myopia cannot be answered from this study.
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Highway construction projects have direct impacts on adjacent businesses. The nature and the degree of impact depend on individual business characterization and project specific factors. The type of business is also a relevant factor in predicting the impact of transportation construction projects. This paper presents the results of research focused on developing an in-depth understanding of these relationships. The study includes project case studies of three transportation construction projects in Florida. Surveys were conducted with all adjacent businesses, which were combined with analyses of the business accommodation procedures employed by State Highway Agencies (SHAs) nationwide to provide measure the efficiency of present rules. The results include an analysis of differing priorities for different classification of businesses and development of design and construction management best practices to better accommodate businesses during highway construction. A pilot project that employed business accommodation principles devised in this research, and improvements to business accommodations observed were compared to cases where no measures were taken.
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Purpose People with diabetes have accelerated age-related biometric ocular changes compared with people without diabetes. We determined the effect of Type 1 diabetes on amplitude of accommodation. Method There were 43 participants (33 ± 8 years) with type 1 diabetes and 32 (34 ± 8 years) age-balanced participants without diabetes. There was no significant difference in the mean equivalent refractive error and visual acuity between the two groups. Amplitude of accommodation was measured using two techniques: objective — by determining the accommodative response to a stimulus in a COAS-HD wavefront aberrometer (Wavefront Sciences), and subjective — with a Badal hand optometer (Rodenstock). The influences of age and diabetes duration (in years) on amplitude of accommodation were analyzed using multiple regression analysis. Results Across both groups, objective amplitude was less than subjective amplitude by 1.4 ± 1.2 D. People with diabetes had lower objective (2.7 ± 1.6 D) and subjective (4.0 ± 1.7 D) amplitudes than people without diabetes (objective 4.1 ± 2.1 D, subjective 5.6 ± 2.1 D). For objective amplitude and the whole group, the duration of diabetes contributed 57% of the variation as did age. For the objective amplitude and only the diabetes group this was 78%. For subjective amplitude, the corresponding proportions were 68% and 103%. Conclusions Both objective and subjective techniques showed lowered amplitude of accommodation in participants with type 1 diabetes when compared with age-matched controls. The loss correlated strongly with duration of diabetes. The results suggest that individuals with diabetes will experience presbyopia earlier in life than people without diabetes, possibly due to metabolic changes in the lens.
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Purpose: To determine the effect of Type 1 diabetes (DM1) on amplitude of accommodation. Method: There were 43 participants (33 ± 8 years) with DM1 and 32 (34 ± 8 years) age-balanced controls. Amplitude was measured objectively with a COAS wavefront aberrometer and subjectively with a Badal hand optometer. Results: Across both groups, objective amplitude was less than subjective amplitude by 1.4 ± 1.2 D. People with diabetes had lower objective (2.7±1.6 D) and subjective (4.0±1.7 D) amplitudes than people without diabetes (objective 4.1±2.1 D, subjective 5.6±2.1 D). For the DM1 group, the objective and subjective multivariate linear regressions were 7.1 – 0.097Age – 0.076DiabDur (R2 0.51) and 9.1 –0.103Age – 0.106DiabDur (R2 0.63), respectively. Conclusion: Objective and subjective techniques showed lowered amplitude of accommodation in DM1 participants compared with age-matched controls. Loss was affected strongly by duration of diabetes. People with diabetes will experience presbyopia earlier in life than people without diabetes.
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PURPOSE. To investigate effects of luminance and accommodation stimuli on pupil size and pupil center location and their implications for progressive addition lens wear. METHODS. Participants were young and older adult groups (n=20, 22±2 years, age range 18-25 years; n=19, 49±4 years, 45-58 years). A wave aberrometer included a relay system to allow a 12.5°x11° background for the internal fixation target. Participants viewed the target under a matrix of conditions with luminance levels 0.01, 3.7, 120 and 6100 cd/m² and with accommodation stimuli up to 6 diopters in 2 diopter steps. Pupil sizes and their centers, relative to limbus centers, were determined from anterior eye images. RESULTS. With luminance increase, reduction in pupil size was accentuated by increase in accommodation stimulus in the young, but not in the older, group. As luminance increased, pupil center location altered. This was nasally in both groups with an average shift of approximately 0.12mm. Relative to the lowest stimulus condition, the mean of the maximum absolute pupil center shifts was 0.26±0.08mm for both groups with individual shifts up to 0.5mm, findings consistent with previous studies. There was no significant effect of accommodation on pupil center locations for either age group, or evidence that location was influenced by the combination of luminance and accommodation stimulus that resulted in any particular pupil size. CONCLUSIONS. Variations in luminance and accommodation influence pupil size, but only the former affects pupil center location significantly. Pupil center shifts are too small to be of concern in fitting progressive addition lenses.
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This thesis examines the short-term changes occurring in a number of the eye's structures during reading tasks, and explores how these changes differ between normal eyes, and those with short-sightedness (myopia). This research revealed changes in the shape and thickness of a number of the eye's structures during near work, and aspects of these changes showed differences associated with myopia. These findings have potentially important implications for our understanding of the role of near work in the development and progression of myopia.
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Purpose There have been only a limited number of studies examining the accommodative response that occurs when the two eyes are provided with disparate accommodative stimuli, and the results from these studies to date have been equivocal. In this study, we therefore aimed to examine the capacity of the visual system to aniso-accommodate by objectively measuring the interocular difference in the accommodation response between fellow dominant and non-dominant eyes under controlled monocular and binocular viewing conditions during short-term exposure to aniso-accommodative stimuli. Methods The accommodative response of each eye of sixteen young isometropic adults (mean age 22 ± 2 years) with normal binocular vision was measured using an open-field autorefractor during a range of testing conditions; monocularly (accommodative demands ranging from 1.32 to 4.55 D) and binocularly while altering the accommodation demand for each eye (aniso-accommodative stimuli ranging from 0.24 to 2.05 D). Results Under monocular viewing conditions, the dominant and non-dominant eyes displayed a highly symmetric accommodative response; mean interocular difference in spherical equivalent 0.01 ± 0.06 D (relative) and 0.22 ± 0.06 D (absolute) (p>0.05). During binocular viewing, the dominant eye displayed a greater accommodative response (0.11 ± 0.34 D relative and 0.24 ± 0.26 D absolute) irrespective of whether the demand of the dominant or non-dominant eye was altered (p = 0.01). Astigmatic power vectors J0 and J45 did not vary between eyes or with increasing accommodation demands under monocular or binocular viewing conditions (p>0.05). Conclusion The dominant and non-dominant eyes of young isometropic individuals display a similar consensual lag of accommodation under both monocular and binocular viewing conditions, with the dominant eye showing a small but significantly greater (by 0.12 to 0.25 D) accommodative response. Evidence of short-term aniso-accommodation in response to asymmetric accommodation demands was not observed.
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Purpose. To characterize the changes occurring in choroidal thickness (ChT) across the posterior pole during accommodation using enhanced-depth imaging optical coherence tomography (OCT). Methods. Forty participants (mean age 21 ± 2 years) had measures of ChT and ocular biometry taken during accommodation to 0, 3, and 6 diopter (D) stimuli, with the Spectralis OCT and Lenstar biometer. A Badal optometer and cold mirror system was mounted on both instruments, allowing measurement collection while subjects viewed an external fixation target at varying accommodative demands. Results. The choroid exhibited significant thinning during accommodation to the 6 D stimulus in both subfoveal (mean change, −5 ± 7 μm) and parafoveal regions (P < 0.001). The magnitude of these changes varied by parafoveal meridian, with the largest changes seen in the temporal (−9 ± 12 μm) and inferotemporal (−8 ± 8 μm) meridians (P < 0.001). Axial length increased with accommodation (mean change, +5 ± 11 μm at 3 D, +14 ± 13 μm at 6 D), and these changes were weakly negatively associated with the choroidal changes (r2 = 0.114, P < 0.05). Conclusions. A small, but significant thinning of the choroid was observed at the 6 D accommodation demand, which was greatest in the temporal and inferotemporal parafoveal choroid, and increased with increasing eccentricity from the fovea. The regional variation in the parafoveal thinning corresponds to the distribution of the nonvascular smooth muscle within the uvea, which may implicate these cells as the potential mechanism by which the choroid thins during accommodation.
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Purpose To provide a summary of the classic paper "Differences in the accommodation stimulus response curves of adult myopes and emmetropes" published in Ophthalmic and Physiological Optics in 1998 and to provide an update on the topic of accommodation errors in myopia. Summary The accommodation responses of 33 participants (10 emmetropes, 11 early onset myopes and 12 late onset myopes) aged 18-31 years were measured using the Canon Autoref R-1 free space autorefractor using three methods to vary the accommodation demand: decreasing distance (4 m to 0.25 cm), negative lenses (0 to -4 D at 4 m) and positive lenses (+4 to 0 D at 0.25 m). We observed that the greatest accommodation errors occurred for the negative lens method whereas minimal errors were observed using positive lenses. Adult progressing myopes had greater lags of accommodation than stable myopes at higher demands induced by negative lenses. Progressing myopes had shallower response gradients than the emmetropes and stable myopes; however the reduced gradient was much less than that observed in children using similar methods. Recent Findings This paper has been often cited as evidence that accommodation responses at near may be primarily reduced in adults with progressing myopia and not in stable myopes and/or that challenging accommodation stimuli (negative lenses with monocular viewing) are required to generate larger accommodation errors. As an analogy, animals reared with hyperopic errors develop axial elongation and myopia. Retinal defocus signals are presumably passed to the retinal pigment epithelium and choroid and then ultimately the sclera to modify eye length. A number of lens treatments that act to slow myopia progression may partially work through reducing accommodation errors.
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• The biomechanical properties of the sclera are documented to be altered in eyes with myopia, with the myopic sclera thought to be more susceptible to deformation from otherwise normal ocular forces. • The close anatomical and functional relationship between the ciliary body and sclera suggests that ciliary muscle contraction during accommodation may influence the overlying sclera. • This study aimed to characterise the changes occurring in anterior scleral thickness with accommodation using anterior segment optical coherence tomography (AS-OCT) in young adult myopes and emmetropes.