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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Assessment of Patient Satisfaction and Willingness to Pay for Ready-Made Bifocals and Reading Spectacles in a 35 Years or Older Clinic Population in Granada, Nicaragua

Hookway, Larry Allen 01 January 2011 (has links)
Background: The World Health Organization estimates that there are 517 million people in the world who are visually impaired due to uncorrected presbyopia. Equal sphere ready-made bifocal and single vision reading spectacles are an inexpensive alternative to custom made spectacles. Methods: A visual satisfaction questionnaire was administered before patients were examined at an outreach clinic and again after ready-made bifocals or reading spectacles were dispensed. The results of both sets of questions along with presenting acuities, corrected acuities, refractive data, and willingness to pay were analyzed. Results: There was an unmet need of 38% (of the 338 subjects that needed glasses only 208 had them). There was no gender bias; the unmet need was higher in the rural areas (47% rural, 36% urban). Those who could not read were 3.4 times less likely to have the glasses they needed than the literate. Unmet need decreased with every level of education. Those without any schooling showed 77% prevalence of unmet need and those with university education had an unmet need rate of 32%. Ready-made spectacles were dispensed to 89.5% of those examined. The ready-made bifocals were very well accepted, with the percentage of subjects giving the highest satisfaction rating improving from a presenting value of 11% to 89.4% with the bifocals at distance and from 6.6% to 89.4% at near. Distance visual acuity of 20/40 or better improved from the presenting value of 60% to 84.5% and near vision of 20/40 or better improved from the presenting value of 44% to 97%. With ready-made single vision readers, functionally good near vision (20/40 or better) improved from a presenting value of 38% to 97%. The highest ranking for near satisfaction improved from 6.3% to 86.6%. The subjects indicted that they would be willing to pay US$18.39 to replace the bifocals and US$16.67 to replace the readers. Conclusion: There is a high unmet need for vision correction in the population over age 35 in Nicaragua. Dissatisfaction with distance and near vision is very high. Although custom made glasses are ideal, ready-made bifocals and ready-made single vision readers are an acceptable and affordable alternative.
22

Adaptation to Spectacle Wear in Children and Adolescents Diagnosed with Autism

Bade, Annette 15 June 2014 (has links)
Objectives: This study compares wearing time for four months after receiving a new spectacle correction in subjects within Autism Spectrum Disorder (ASD) population to typically developing (TD) children and adolescents age 9 to 17 years old. Methods: Children and adolescents who were ASD or TD were enrolled from subjects recruited from another pilot study focused on eye examination testing for children and adolescents with ASD. A psychologist determined group status/ eligibility using American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition-Text Revision (DSM-IV-TR) criteria after review of previous evaluations and parent report of symptomology on the Social Communication Questionnaire. Parents provided the subject's age, level of parent education, gender, race, ethnicity and urbanization level. Parents completed a telephone survey at 1, 2, 4, 8, 12, and 16 weeks after the child received their spectacles. The survey asked questions about wearing time, willingness to wear spectacles and amount of prompting required. Data was analyzed to determine if there were differences between the ASD and TD group. Results: 22 subjects were enrolled who met review criteria for ASD or TD group and needed refractive correction. No significant difference was found between ASD and TD wearing time (p > 0.05). Age, gender, ethnicity, level of parent education, urbanization level and grade in school did not demonstrate differences in adaptation between the TD and ASD groups. Conclusions: Parental reports of wearing time and resistant behavior demonstrate that children and adolescents with ASD adapt to spectacle wear for significant refractive error similarly to typical children and adolescents.
23

Comprehensive Replication of the Relationship Between Myopia-Related Genes and Refractive Errors in a Large Japanese Cohort. / 近視関連遺伝子群と日本人コホートにおける屈折異常との関係の網羅的再現性検証

Yoshikawa, Munemitsu 23 March 2017 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第20278号 / 医博第4237号 / 新制||医||1021(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 森田 智視, 教授 佐藤 俊哉, 教授 中山 健夫 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM
24

Gaining Focus: Using RNAi during Lens Development to Understand Emmetropization Mechanisms Found within the Diving Beetle Larvae Thermonectus Marmoratus

Hassert, Jennifer C. 19 November 2019 (has links)
No description available.
25

Contact Lens, Academics and Self-Perception Study: Follow-up Results

Miller, Karina Y. 06 October 2020 (has links)
No description available.
26

Sphero-cylindrical Refraction with Spherical Lenses

Lehman, Joseph Christian 01 October 2020 (has links)
No description available.
27

Vision and visual history in elite/near-elite level cricketers and rugby-league players

Barrett, Brendan T., Flavell, Jonathan C., Bennett, S.J., Cruickshank, Alice G., Mankowska, Aleksandra, Harris, J.M., Buckley, John 10 November 2017 (has links)
Yes / Background: The importance of optimal and/or superior vision for participation in high-level sport remains the subject of considerable clinical research interest. Here we examine the vision and visual history of elite/near-elite cricketers and rugby-league players. Methods: Stereoacuity (TNO), colour vision, and distance (with/without pinhole) and near visual acuity (VA) were measured in two cricket squads (elite/international-level, female, n=16; near-elite, male, n=23) and one professional rugby-league squad (male, n=20). Refractive error was determined, and details of any correction worn and visual history were recorded. Results: Overall, 63% had their last eye-examination within 2 years. However, some had not had an eye examination for 5 years, or had never had one (near-elite-cricketers: 30%; rugby-league players: 15%; elite-cricketers: 6%). Comparing our results for all participants to published data for young, optimally-corrected, non-sporting adults, distance VA was ~1 line of letters worse than expected. Adopting α=0.01, the deficit in distance-VA deficit was significant, but only for elite-cricketers (p<0.001) (near-elite cricketers, p=0.02; rugby-league players, p=0.03). Near-VA did not differ between subgroups or relative to published norms for young adults (p>0.02 for all comparisons). On average, stereoacuity was better than in young adults, but only in elite-cricketers (p<0.001; p=0.03, near-elite-cricketers; p=0.47, rugby-league -players). On-field visual issues were present in 27% of participants, and mostly (in 75% of cases) comprised uncorrected ametropia. Some cricketers (near-elite: 17.4%; elite: 38%) wore refractive correction during play but no rugby-league player did. Some individuals with prescribed correction choose not to wear it when playing. Conclusion: Aside from near stereoacuity in elite-cricketers, these basic visual abilities were not better than equivalent, published data for optimally-corrected adults. 20-25% exhibited sub-optimal vision, suggesting that the clearest possible vision might not be critical for participation at the highest levels in the sports of cricket or rugby-league. Although vision could be improved in a sizeable proportion of our sample, the impact of correcting these, mostly subtle, refractive anomalies on playing performance is unknown. / Funded by the UK’s Biotechnology and Biological Sciences Research Council (BBSRC) grants BB/J018163/1, BB/J016365/1 and BB/J018872/1.
28

Transient axial length change during the accommodation response in young adults

Mallen, Edward A.H., Hampson, Karen M., Kashyap, Priti January 2006 (has links)
No / The aims of the research may be outlined as follows: to measure the degree of transient axial elongation during the accommodation response in emmetropic and myopic young adults. To evaluate the effect of refractive error and accommodative demand on transient axial elongation of the eye. Axial length of the right eye was measured in 30 emmetropes and 30 myopes, by using the IOLMaster (Carl Zeiss Meditec, Inc., Dublin, CA), while accommodative stimuli of 0, 2, 4 and 6 D were presented with a Badal optometer. Axial length increased in both emmetropic and myopic subjects during short periods of accommodative stimulation. Greater transient increases in axial length were observed in myopic than in emmetropic subjects. The mean axial elongation with a 6-D stimulus to accommodation was 0.037 mm in emmetropes and 0.058 mm in myopes (P = 0.02). The degree of transient axial elongation correlated well with the stimulus to accommodation in emmetropes and myopes. Anterior chamber depth decreased, on average, by 0.19 mm in emmetropes and 0.18 mm in myopes when observing a 6-D stimulus to accommodation. During relatively short periods of accommodative stimulation, axial length increases in both emmetropic and myopic young adults. At higher levels of accommodative stimulation, a significantly greater transient increase in axial length is observed in myopic subjects than in their emmetropic counterparts.
29

Correcting ocular spherical aberration with soft contact lenses.

Cox, Michael J., Dietze, Holger H. January 2004 (has links)
No / Following aberroscopy, aspheric front surface soft contact lenses (SCLs) were custom-made to correct spherical refractive error and ocular spherical aberration (SA) of 18 myopic and five hypermetropic subjects (age, 20.5 . 5 yr). On-eye residual aberrations, logMAR visual acuity, and contrast sensitivity were compared with the best-correcting spectacle lens, an equally powered standard SCL, and an SCL designed to be aberration free in air. Custom-made and spherical SCLs reduced SA ( p . 0.001; p . 0.05) but did not change total root-meansquare (rms) wave-front aberration (WFA). Aberration-free SCLs increased SA ( p . 0.05), coma ( p . 0.05), and total rms WFA. Visual acuity remained unchanged with any of the SCL types compared with the spectacle lens correction. Contrast sensitivity at 6 cycles/degree improved with the custom-made SCLs ( p . 0.05). Increased coma with aspheric lens designs and uncorrected astigmatism limit the small possible visual benefit from correcting ocular SA with SCLs.
30

Genetic prediction of myopia: prospects and challenges

Guggenheim, J.A., Ghorbani Mojarrad, Neema, Williams, C., Flitcroft, D.I. 08 November 2019 (has links)
Yes / Appeals have been made for eye care professionals to start prescribing anti-myopia therapies as part of their routine management of myopic children. 1–3 These calls are fuelled by two key considerations. Firstly, that interventions to slow myopia progression have shown success in randomized controlled trials (RCTs) 4–7, and secondly, appreciation that the risk of sight-threatening complications rises dose-dependently with the level of myopia. 8,9 Notwithstanding existing gaps in knowledge regarding the efficacy of current treatments (see below), these considerations argue that myopia control interventions should be widely adopted, and that they should be instigated at an early age – especially in children most at risk – in order to reduce the final level of myopia. Therefore in managing a child with myopia, an eye care professional would have to decide not only which therapy to recommend, but at what age to start treatment. In this review we discuss the future role of genetic prediction in helping clinicians treat myopia. / NIHR Senior Research Fellowship. Grant Number: SRF‐2015‐08‐005

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