• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 43
  • 1
  • Tagged with
  • 49
  • 49
  • 20
  • 15
  • 13
  • 8
  • 7
  • 7
  • 6
  • 5
  • 5
  • 5
  • 5
  • 5
  • 5
  • 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

Refractive error, ocular biometry and oculomotor function: The prevalence of myopia and its potential risk factors in the Middle East, with an investigation of dynamic accommodation responses and axial length fluctuations in young myopic adults.

Gammoh, Yazan S.S. January 2011 (has links)
The main experimental work of this thesis has been a cross-sectional study of the prevalence of refractive error and its biometric correlates in Middle Eastern adults. In addition dynamic accommodative responses and twenty-four hour axial length fluctuations were investigated in young myopic adults. The prevalence of myopia in 3000 Middle Eastern adults (age range 17-40 years) was similar to previously reported levels of myopia in the West. Myopia was associated with a higher level of education, occupations with a high nearwork demand and positive family history of myopia; all of which have been identified as risk factors for myopia development and progression Diurnal variations in axial length (AL) of similar magnitude to those previously reported in emmetropes were observed in myopes recruited in the current thesis. However, the pattern of the diurnal variation in AL was significantly different between early-onset myopes (EOMs) and late-onset myopes (LOMs). There were no significant differences between EOMs and LOMs in the dynamic accommodative response to a sinusoidally oscillating target. The accommodative phase lag was increased following 30 minute adaptation to myopic defocus using +2.00 D lens. However, intense prolonged (30 minute) nearwork was found to have no effect on accommodative gain or phase lag. A number of recommendations for further work on the prevalence of refractive error in the Middle East are suggested along with further research on diurnal AL variations and dynamic accommodative responses in EOMs and LOMs.
28

Peripheral Refractive Error and its Association with Myopia Development and Progression. An examination of the role that peripheral retinal defocus may play in the origin and progression of myopia

Jamal, Heshow January 2019 (has links)
Purpose: Currently there are attempts to slow myopia progression by manipulating peripheral refractive error. This study proposed to establish the distribution of peripheral refractive errors in hyperopic, emmetropic and myopic children and to test the hypothesis that relative peripheral hyperopia is a risk factor in the onset and progression of myopia. Methods: Refraction was measured under non-cycloplegic conditions, at 0°, 10° (superior, inferior, temporal and nasal retina) and 30° (temporal and nasal retina), at distance and near. Central spherical equivalent refractive error (SER) was used to classify the eyes as myopic (≤ −0.75 D), emmetropic (−0.75 < SER < +0.75 D) or hyperopic (≥ +0.75 D). Relative peripheral refraction was calculated as the difference between the central (i.e. foveal) and peripheral refractive measurements. At baseline, measurements were taken from 554 children and in a subset of 300 of these same children at the follow-up visit. The time interval between initial and follow-up measurement was 9.71 ± 0.87 months. Results: Results were analysed on 528 participants (10.21 ±0.94 years old) at baseline and 286 longitudinally. At baseline, myopic children (n=61) had relative peripheral hyperopia at all eccentricities at distance and near, except at 10°-superior retina where relative peripheral myopia was observed at near. Hyperopic eyes displayed relative peripheral myopia at all eccentricities, at distance and near. The emmetropes showed a shift from relative peripheral myopia at distance to relative peripheral hyperopia at near at all eccentricities, except at 10°-superior retina, where the relative peripheral myopia was maintained at near. In the longitudinal data analysis, myopes who became more myopic did not show greater relative peripheral hyperopia at baseline compared with myopic sub-groups whose central refraction remained stable. Conclusions: The peripheral refractive profile differences between different refractive groups that are reported in other studies have been confirmed in this study. Relative peripheral hyperopia is not found to be a significant risk factor in the onset or progression of myopia in children.
29

Commercialization of Software for the Prediction of Structural and Optical Consequences Resulting from Corneal Corrective Treatments

Lloyd, Joshua S. 26 January 2016 (has links)
No description available.
30

Refractive error shift with continuous use (Rescu) lenses

Merchea, Mohinder Mohan 01 October 2003 (has links)
No description available.

Page generated in 0.0163 seconds