Yes / Background: A range of myopia management (MM) contact lenses are becoming available to practitioners. These lenses are designed to slow myopia progression and axial elongation. This study explored the initial experience of participants wearing daily disposable MM contact lenses to investigate established factors previously associated with successful lens wear. Methods: This was a prospective, double-masked, crossover study. Twenty participants aged 18–30 years old were assigned to wear two daily disposable MM lenses in a randomised order. Visual acuity, contrast sensitivity, and amplitude/lag of accommodation were assessed at baseline, post-insertion, and after 2 and 6 h of lens wear. Self-reported lens comfort and vision quality were recorded at the same timepoints, and at 10 h post-insertion. Pairwise comparisons were performed between the two lenses at each timepoint, as well as assessing changes throughout wear. The relationship of the measured parameters to overall lens satisfaction was also assessed. Results: There were no significant differences between the two MM lenses at any timepoint for any of the participant-reported parameters, including overall satisfaction. A small difference in visual acuity was noted at 6 h post-insertion, although this is unlikely to be clinically significant. Comfort decreased throughout the day, most notably at 10 h post-insertion. A moderate positive correlation was observed between participant-reported visual quality and overall satisfaction. A similar pattern was seen for comfort and overall satisfaction. Self-reported vision quality and measured visual acuity were poorly correlated, highlighting the benefit of subjectively assessing the quality of vision with these lenses. Conclusions: The participants demonstrated comparable measures across a range of measures between the two MM lenses. Notably, half of the participants demonstrated a clear lens preference, although the preferred lens varied between individuals. Candidates for MM may benefit from trialling more than one MM lens design, to maximise initial wearing satisfaction. / This project was supported by the British Contact Lens Association Summer Research Scholarship.

No description available.

Objetivos: Avaliar a freqüência de miopia como causa de deficiência visual em sujeitos com idade entre 10 a 15 anos residentes na cidade de Gurupi assim como a sua relação com a distribuição com idade e sexo. Métodos: Estudo transversal populacional. Foram sorteados e avaliados 50 conglomerados dos 59 anteriormente utilizados pelo IBGE para a realização do Censo 2000 compreendendo toda a cidade de Gurupi. Uma equipe treinada visitou as casas seguindo uma ordem de quarteirões definidos previamente pelo IBGE. Foram usados como critérios de inclusão idade de 10 a 15 anos e residir no local por, pelo menos, seis meses. As residências em que não houve resposta foram revisitadas em uma segunda oportunidade. Após explicação do trabalho e o consentimento por escrito de um responsável, com a ajuda deste, foi preenchida uma ficha com os dados do sujeito. Foi avaliada a acuidade visual de cada olho sem correção, separadamente com cinco optotipos impressos de Snellen em linha correspondentes a visão 20/32 da tabela logMAR, a uma distância de 4 metros. Os sujeitos que apresentaram dificuldade de visualizar mais de um optotipo com um ou ambos os olhos foram encaminhados para avaliação em consultório por um oftalmologista. Foi realizado teste de motilidade ocular e revistada a acuidade visual com tabela de logMar retro iluminada a 4 metros. Após cicloplegia, foi feita a auto-refração, seguido da refração subjetiva utilizando tabela logMar , exame externo, biomicroscopia e fundoscopia. Foi prescrita a correção para os sujeitos que apresentaram melhora da acuidade visual após a refração. A deficiência foi classificada em refrativa, catarata, tracoma, ambliopia, alterações retinianas, estrabismo e outros. Resultados: Foram examinados 1590 sujeitos com idade variando entre 10 a 15 anos, sendo 814 (51%) do sexo masculino e 776 (49%) do sexo feminino. Dos 167 que apresentaram limitações para identificar os optotipos de Snellen, 127 (76%) compareceram para a avaliação em consultório, sendo que 61 (59%) não necessitaram de correção. Das correções, 15 (22%) foram corrigidos com lentes com equivalente esférico positivo. As prescrições com equivalente esférico negativo somaram 51 (77%) com variação entre -0,5 até -7,00 dioptrias esféricas, correspondendo a uma freqüência de miopia de 3,2%. Destes, 23 (45%) eram do sexo masculino e 28 (55%) do sexo feminino. Dos sujeitos que necessitaram de óculos, nove (10%) ainda não faziam uso prévio de correção. Os erros refrativos foram a principal causa de deficiência de visão, responsáveis por 53 (80%) dos casos, sendo 45 (90%) míopes e oito (10%) hipermetropes. Em seguida, ambliopia com 8 (12%) sujeitos, 4 (6%) com alterações retinianas e 1 (1%) com catarata congênita. As variáveis sexo, idade, região onde residia, uso prévio de óculos foram associadas com a miopia por regressão multivariada sem nenhuma relação significativa. Conclusão: Os erros refrativos são a principal causa de baixa de visão na faixa de idade examinada, com destaque para a miopia, que apresentou uma freqüência de 3,2%. Nenhum dos fatores estudados apresentou relação estatística com a presença de miopia / Objective: To evaluate the frequency of visual impairment caused by myopia in subjects from 10 to 15 years old in the city of Gurupi and its relation with some factors studied in this age group. Methods: Population-based, transversal study. 50 from 59 clusters from Gurupi - TO, previously used by IBGE (2000), were randomized. All subjects from 10 to 15 years old, living in the same place for at least 6 months were included. Vision was tested in each eye, without correction, with five Snelle\'s optotypes, corresponding to 20/32 in logMar chart, at four meters distance. When the subjects could not see one or more optotypes with one or both eyes, they were referred to an ophthalmological examination. In the physician office, eye motility was tested and visual acuity was retested the with the logMar chart. After cicloplegia, auto refraction was performed, followed by the subjective refraction (using a retroilluminated logMar chart), inspection, biomicroscopy and fundoscopy. Lenses were prescribed after refraction to patients who showed visual acuity improvement. The causes of visual impairment were classified in refractive, cataract, trachoma, ambliopia, retinopathy, strabismus and others. Results: 1,590 subjects were examined, in which 814 (51%) were male and 776 (49%) were female. Among the 167 subjects screened, 127 (76%) were examined at the physician office and 76 (59%) did not receive lens prescription. 15 patients (22%) of those displayed positive spherical equivalent and 51 (77%) presented with negative spherical equivalent (varying from -0,5 to -7,00 D), totalizing a frequency of 3.2%. 23 (45%) myopic patients were male and 28 (55%) female. Refractive errors were the main cause of visual impairment [53 (80%); myopia in 45 and hypermetropia in 8), followed by ambliopia (8, 12%), retinopathies (4, 6%) and congenital cataract (1, 1%). Multivariate analysis of the association of the variables gender, age, region, previous ophthalmic examination and previous glasses with myopia did not present significant relation. Conclusion: Refractive errors were the major cause of visual impairment in this age group (80%), mainly represented by myopia, with a general frequency of 3.2%. No co-variable studied displayed statistical relation with the presence of myopia

Objetivos: Avaliar a freqüência de miopia como causa de deficiência visual em sujeitos com idade entre 10 a 15 anos residentes na cidade de Gurupi assim como a sua relação com a distribuição com idade e sexo. Métodos: Estudo transversal populacional. Foram sorteados e avaliados 50 conglomerados dos 59 anteriormente utilizados pelo IBGE para a realização do Censo 2000 compreendendo toda a cidade de Gurupi. Uma equipe treinada visitou as casas seguindo uma ordem de quarteirões definidos previamente pelo IBGE. Foram usados como critérios de inclusão idade de 10 a 15 anos e residir no local por, pelo menos, seis meses. As residências em que não houve resposta foram revisitadas em uma segunda oportunidade. Após explicação do trabalho e o consentimento por escrito de um responsável, com a ajuda deste, foi preenchida uma ficha com os dados do sujeito. Foi avaliada a acuidade visual de cada olho sem correção, separadamente com cinco optotipos impressos de Snellen em linha correspondentes a visão 20/32 da tabela logMAR, a uma distância de 4 metros. Os sujeitos que apresentaram dificuldade de visualizar mais de um optotipo com um ou ambos os olhos foram encaminhados para avaliação em consultório por um oftalmologista. Foi realizado teste de motilidade ocular e revistada a acuidade visual com tabela de logMar retro iluminada a 4 metros. Após cicloplegia, foi feita a auto-refração, seguido da refração subjetiva utilizando tabela logMar , exame externo, biomicroscopia e fundoscopia. Foi prescrita a correção para os sujeitos que apresentaram melhora da acuidade visual após a refração. A deficiência foi classificada em refrativa, catarata, tracoma, ambliopia, alterações retinianas, estrabismo e outros. Resultados: Foram examinados 1590 sujeitos com idade variando entre 10 a 15 anos, sendo 814 (51%) do sexo masculino e 776 (49%) do sexo feminino. Dos 167 que apresentaram limitações para identificar os optotipos de Snellen, 127 (76%) compareceram para a avaliação em consultório, sendo que 61 (59%) não necessitaram de correção. Das correções, 15 (22%) foram corrigidos com lentes com equivalente esférico positivo. As prescrições com equivalente esférico negativo somaram 51 (77%) com variação entre -0,5 até -7,00 dioptrias esféricas, correspondendo a uma freqüência de miopia de 3,2%. Destes, 23 (45%) eram do sexo masculino e 28 (55%) do sexo feminino. Dos sujeitos que necessitaram de óculos, nove (10%) ainda não faziam uso prévio de correção. Os erros refrativos foram a principal causa de deficiência de visão, responsáveis por 53 (80%) dos casos, sendo 45 (90%) míopes e oito (10%) hipermetropes. Em seguida, ambliopia com 8 (12%) sujeitos, 4 (6%) com alterações retinianas e 1 (1%) com catarata congênita. As variáveis sexo, idade, região onde residia, uso prévio de óculos foram associadas com a miopia por regressão multivariada sem nenhuma relação significativa. Conclusão: Os erros refrativos são a principal causa de baixa de visão na faixa de idade examinada, com destaque para a miopia, que apresentou uma freqüência de 3,2%. Nenhum dos fatores estudados apresentou relação estatística com a presença de miopia / Objective: To evaluate the frequency of visual impairment caused by myopia in subjects from 10 to 15 years old in the city of Gurupi and its relation with some factors studied in this age group. Methods: Population-based, transversal study. 50 from 59 clusters from Gurupi - TO, previously used by IBGE (2000), were randomized. All subjects from 10 to 15 years old, living in the same place for at least 6 months were included. Vision was tested in each eye, without correction, with five Snelle\'s optotypes, corresponding to 20/32 in logMar chart, at four meters distance. When the subjects could not see one or more optotypes with one or both eyes, they were referred to an ophthalmological examination. In the physician office, eye motility was tested and visual acuity was retested the with the logMar chart. After cicloplegia, auto refraction was performed, followed by the subjective refraction (using a retroilluminated logMar chart), inspection, biomicroscopy and fundoscopy. Lenses were prescribed after refraction to patients who showed visual acuity improvement. The causes of visual impairment were classified in refractive, cataract, trachoma, ambliopia, retinopathy, strabismus and others. Results: 1,590 subjects were examined, in which 814 (51%) were male and 776 (49%) were female. Among the 167 subjects screened, 127 (76%) were examined at the physician office and 76 (59%) did not receive lens prescription. 15 patients (22%) of those displayed positive spherical equivalent and 51 (77%) presented with negative spherical equivalent (varying from -0,5 to -7,00 D), totalizing a frequency of 3.2%. 23 (45%) myopic patients were male and 28 (55%) female. Refractive errors were the main cause of visual impairment [53 (80%); myopia in 45 and hypermetropia in 8), followed by ambliopia (8, 12%), retinopathies (4, 6%) and congenital cataract (1, 1%). Multivariate analysis of the association of the variables gender, age, region, previous ophthalmic examination and previous glasses with myopia did not present significant relation. Conclusion: Refractive errors were the major cause of visual impairment in this age group (80%), mainly represented by myopia, with a general frequency of 3.2%. No co-variable studied displayed statistical relation with the presence of myopia

Orthokeratology (OK) is the reduction, modification or elimination of myopia through application of contact lenses. With the development of high Dk/t lens materials, overnight therapy has become the modality of choice for OK. Overnight OK lens wear has been previously investigated in terms of its efficacy to reduce myopia. However, the underlying effects of overnight OK lens wear on the human cornea have received less attention. As well as the clinical efficacy of overnight OK, this study investigated the effects of overnight OK on topographical corneal thickness and the overnight corneal edema response, and corneal tissue changes with overnight OK. Eighteen subjects participated as the OK lens-wearing group, wearing BE lenses (UltraVision, Brisbane, Queensland) in both eyes. A further ten subjects participated as control subjects, wearing conventional rigid lenses (J-Contour, UltraVision) in the right eye (RE) only. The left eye (LE) acted as a non-lens-wearing control. Both groups wore lenses overnight only, with no lens wear during the day. Measurements were conducted at baseline then on day 1, 4, 10, 30, 60, and 90 for the OK lens-wearing eyes; and up to day 30 for the control group, in the morning (after overnight lens wear) and in the evening (after 8-10 hours of lens removal). Variables measured included best vision sphere (BVS), unaided logMAR visual acuity (VA), refractive astigmatism, apical corneal power (ACP), simulated K readings (Medmont E300 corneal topographer), topographical corneal thickness (Holden-Payor optical pachometer), and keratocyte and endothelial cell densities (ConfoScan2 confocal microscope). Approximately 75% of myopia was corrected after the first night of OK lens wear and the changes in refractive error stabilised by day 10. By day 90, myopia reduction averaged 2.54 ?? 0.63 D. This was associated with significant improvement in unaided VA of about 82% after the first night of lens wear. There was no change in refractive astigmatism over the 3-month period. There was significant reduction in ACP in the OK lens-wearing eyes after the first night of lens wear, which accounted for more than 70% of the total ACP change over the 3-month period (RE: -2.16 ?? 0.53 D; LE: -2.11 ?? 0.86 D). There was significant central epithelial thinning (about 30%) and significant thickening (about 3%) in the mid-peripheral stroma in the OK lens-wearing eyes. Significant central epithelial thinning was found after the first night of lens wear while thickening in the mid-peripheral stroma reached statistical significance by day 4. Further analysis suggests that topographical corneal thickness changes account for the refractive error changes with overnight OK lens wear, rather than corneal bending. The central overnight stromal edema response was significantly reduced in the OK lens-wearing eyes (1.2 ?? 0.5%) to a level lower than in the conventional RGP (6.2 ?? 1.2%) and non-lens-wearing eyes (2.5 ?? 0.9%) in the control group. Mid-peripheral and peripheral stromal edema responses showed similar levels to those predicted based on lens Dk/t. A single overnight wear of BE and Paragon Corneal Refractive Therapy (CRT) lenses showed that the edema response to BE lens wear is significantly less than in the CRT lens-wearing eyes (BE: 2.5 ?? 0.7%; CRT 3.5 ?? 1.3%) immediately on eye opening. No significant changes were found in either central stromal keratocyte or endothelial cell densities in either OK or control groups over the study period. In conclusion, overnight OK lens wear induces significant reductions in myopia after the first night of lens wear associated with improvement in unaided VA. Overnight OK lens wear causes significant thinning in the central epithelium and significant mid-peripheral stromal thickening which results in flattening of the central cornea and steepening in the mid-periphery. Although there were no significant changes in central stromal keratocyte and endothelial cell densities, thinning of the central epithelial layer raises concerns regarding the safety of the procedure, especially with the alarming number of corneal infections reported recently in the literature.

Purpose: To investigate whether retinal thickness varies with refractive error. Also secondary to see if there is any difference in retinal thickness between the right and left eye. Methods: The inclusion criteria for the study was subjects without any pathologies, age between 18-45 and refractive error of maximum +0.75 SER and the myopia had no limit, as well as no astigmatism higher then -1.00D. Subjects, which fitted the inclusion criteria for the study, was shown to the OCT room were retinal thickness measurements were acquired first on the right and then left eye. To get the same reading area, the same setup was used and the fixation point was always centered for each patient. After all subjects had undergone the same method the results were analyzed using t-test and regression analysis. Results: The analysis showed a difference between emmetropic eyes and myopic eyes in the peripheral retinal thickness, having the myopes being significantly thinner. The inter myopic analysis showed no difference in retinal thickness in any of the points. This could however be due to the smaller sample size. The comparison between right and left eye showed a good symmetry between the two eyes both in the emmetropic and the myopic group. Conclusions: From this study we can conclude that the myopic group has a thinner peripheral retinal thickness than the emmetropic group. Central retinal thickness is not significantly different but could be due to the smaller sample size. There is no difference in retinal thickness between right and left eye.

This thesis has investigated nearwork-induced transient myopia and accommodation responses in relation to refractive stability, multichromatic stimuli and orthokeratology. Five individual studies have been carried out. Initially an investigation into the temporal and dioptric aspects of nearwork-induced transient myopia was undertaken, suggesting that increased task duration does not increase the level, or slow the regression of post-task NITM, however an increase in the dioptric demand of the task does. In the second study, a longitudinal myopia progression study, these findings were related to short term myopia progression. The third investigation demonstrates the feasibility of measuring the biometric correlates of nearwork-induced transient myopia using a low coherence reflectometry device (LenStar, Haag Streit Koeniz, Switzerland). Fourthly, a comparison of the differences between static and dynamic accommodative responses, microfluctuations and nearwork-induced transient myopia produced when viewing a black/white target as oppose to a red/blue target has suggested the possibility of four accommodative responses to this multichromatic stimulus. Further investigation will be necessary to investigate if any of these response types are related to myopia progression. 2 The final study investigates the effect of two different designs of orthokeratology contact lenses (C5 and polynomial) on visual function. It appears to be the case that although the polynomial lens design has a larger refractive effect than the C5 lens it reduces both high and low contrast corrected visual acuity to a greater extent. The higher the baseline mean spherical equivalent refractive error the larger the detrimental effect.

The increasing prevalence of myopia over the past few decades and its association with potential ocular complications make myopia an important research topic. The present work is concerned with the structural and functional characteristics of a group of myopic and emmetropic individuals. The technical experiments in this work investigated firstly the effect of instrument alignment on peripheral refraction measurements and revealed that the corneal vertex was an acceptable alignment position of the Shin-Nippon NVision-K 5001 autorefractor, allowing consistent alignment with other instruments used in this research. Secondly, spectacles could be used to provide comparable vision to contact lenses in the visual performance studies. In the main experimental parts of this work, visual performance and multiple aspects of ocular structure were assessed across a wide range of eccentricities along the horizontal and vertical meridians within the same eyes. The structural properties of the myopic eye were measured through central and peripheral autorefraction, and through cornea to retina dimensions using non-contact biometry. In addition, the central and peripheral resolution acuities of myopic and emmetropic eyes for high and low contrast levels were investigated. Our structural and functional measurements revealed relatively prolate myopic eyes with reduced high contrast resolution acuity, compared to emmetropic eyes. Moreover, multiple regression analyses were performed at the fovea and outermost retinal eccentricities common to all core experiments but revealed no strong relationship between the structure and function of the myopic eye. Finally, regarding asymmetry, the nasal and superior retinae were found to be longer and to perform better in comparison to the temporal and superior retinae respectively.

This thesis aims to investigate whether frequency of mandatory financial reporting affects management focus on long-term growth. Evidence from the market has illustrated how managers within listed firms sometimes strive to meet market expectations on the latest reported earnings regardless of long-term consequences (see for example Graham, Harvey & Rajgopal, 2005; Grinyer, Russell & Collison, 1998). Yet, the existing literature has neglected to research market pressure in terms of financial reporting frequency and its proposed influence on long-term growth. This study seeks to find if a more frequent mandatory reporting affects managers to more often sacrifice long-term growth in terms of reduced R&D investments. By comparing six different stock exchanges with different interim reporting requirements, this study empirically examines the hypothesized relationship, using a robust multiple regression analysis based on 320 observations during the sample period 2008-2012. The statistically significant results show a negative correlation, suggesting that firms that are required to disclose quarterly reports invest less in R&D than firms that are only required to disclose semi-annual reports. A negative correlation is observed for the whole sample as well as for the five sectors individually. The results provide additional empirical evidence to the research fields of financial reporting, managerial myopia and earnings management.

This study provided the first direct test of the cognitive underpinnings of the attention-allocation model and attempted to replicate and extend past behavioral findings for this model as an explanation for alcohol-related aggression. Men were randomly assigned to a beverage (Alcohol, No-Alcohol Control) and a distraction (Moderate Distraction, No Distraction) condition. All men were provoked by a male confederate and completed a dot probe task and a laboratory aggression task without distraction or while presented with a moderate distraction task. Results indicated that intoxicated men whose attention was distracted displayed significantly lower levels of aggression bias and enacted significantly less physical aggression than intoxicated men whose attention was not distracted. However, aggression bias did not account for the lower levels of alcohol-related aggression in the distraction, relative to the no-distraction, condition. Discussion focused on how these data inform intervention programming for alcohol-related aggression.