Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2009.

Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2009.

Thesis (M.B.A.)--North-West University, Potchefstroom Campus, 2009.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / The optopmetric scale is used on oftamologic clinic exam and selecting to determine the visual accuracy. On earlier study, by Dantas (2003), a method was developed for the selections of optoptics for the scale of regionalized images, as a initial proposal. Therefore, in order for this scale to be valid, it is needed to deepen the studies on the relation of the structuring and organizing of these optoptics, with visual accuracy and practical testing. The objectives are: To valid the RAD scale as its capacity to identify children with ocular alterations; Evaluate the co-relation among the coefficients of visual accuracy; Verify the associations among the tests; Verify the agreement of the measurement of the three examiners for the right and left eyes, separately. Study of validation of technology, experimental, random, triple blind, quantitative, developed over the first semester of 2006, having as sample, 246 students, selected on a random simple way. The methodological referential used by the research was adapted from the model of construto test with the theoric, experimental and analytic procedures. For the validation of the RAD scale, statistic coefficients of validating and precision are used. The sensibility for the moments RAD 1 and RAD 2 was respectively 88,6 and 85,7 for the right eye, and 78,6 and 92,9 for the left eye. As to the specificity the values found for the RAD 1 and RAD 2 scales were 95,3 and 98,1 for the right eye, and 97,7 and 98,6 for the left eye. Respectively, the positive predictive value (VP+) on the RAD 1 moment was 75,6 and 81,5 and on the RAD 2 moment, was 88,2 and 89,7; The negative predictive value (VP-) on the RAD 1 moment was 98,0 and 97,3 and on the RAD 2 moment it was 97,6 and 99,1. There was a correlation among the visual accuracy coefficients between âSnellen and RAD 1â, âSnellen and RAD 2â, for the two eyes (p = 0,0001). On the (X2) association were found a coefficient of 151,90 (p = 0,0001) for RAD 1 and 177,07 (p = 0, 0001) fro RAD 2; For the left and right eyes on RAD 1, it was 147,75 (p = 0,0001) and 199.69 (p = 0,0001) on RAD 2 on the right eye. For the concordance analysis in all cases, an Alpha de Cronbach higher than 0,929 was found. The data show significant between the standard criteria used and the scale of images in analysis. According to literature, the validation model in technology establishes rules to be fulfilled. The making of a regionalized chart of figures must fulfill the following rules: Use of the theory of image formation to construct optometric scales. Use of the visual system to characterize the visual learning (step 1); Patterning of the optometric scale as system proprieties. (step 2); Use of dimensionality based on the opticâphysiologic aspects. (step 3); And characterization of the main definitions to be followed on the validation of the images and building of optoptics. (step 4); Demonstration of the operationalization on elaborating optometric scales. (step 5); Analysis of the optoptics of the image scale. (step 6); Planning of the application on the methodology. (step 7); Application and gathering for the measurements of the ocular alterations (step 8); Use of validation techniques (step 9); Use of precision techniques (step 10) and final considerations (step 11). The established rules serve as a starting point to de development of the chart in each region, for each one should have its own characteristic that must be respected. / A escala optomÃtrica à utilizada em exame clÃnico oftalmolÃgico e triagens para determinar a acuidade visual. Em estudo anterior realizado por Dantas (2003), desenvolveu-se um mÃtodo para seleÃÃo dos optÃtipos para escala de figuras regionalizada, como uma proposta inicial. Entretanto, para esta escala ser validada, à necessÃrio aprofundar os estudos na relaÃÃo da estruturaÃÃo e organizaÃÃo desses optÃtipos com a acuidade visual e de testes prÃticos. TÃm-se como objetivos: validar a escala RAD quanto a sua capacidade de identificaÃÃo de crianÃa portadora de alteraÃÃo ocular; avaliar a correlaÃÃo entre os coeficientes da acuidade visual; verificar a associaÃÃo entre os testes; verificar a concordÃncia das medidas dos trÃs examinadores para os olhos direito e esquerdo, separadamente. Estudo de validaÃÃo de tecnologia, experimental, aleatÃrioo, triplo cego, quantitativo, desenvolvido durante o primeiro semestre de 2006 tendo como amostra 246 alunos selecionados de forma aleatÃria simples. O referencial teÃrico metodolÃgico adotado para a pesquisa foi adaptado do modelo de teste de construto contemplando os procedimentos teÃrico, experimental e analÃtico. Para validaÃÃo da escala RAD, utilizaram-se coeficientes estatÃsticos de validade e precisÃo. A sensibilidade para os momentos RAD 1 e RAD 2 foi, respectivamente, 88,6 e 85,7 para o olho direito e 78,6 e 92,9 para o esquerdo. Quanto à especificidade, os valores encontrados para as escalas RAD 1 e RAD 2 foram, respectivamente, 95,3 e 98,1 para o olho direito e 97,7 e 98,6 para o esquerdo. Para os olhos direito e esquerdo, respectivamente, o valor preditivo positivo (VP+) no momento RAD 1 foi de 75,6 e 81,5 e no momento RAD 2 foi de 88,2 e 89,7; jà o valor preditivo negativo (VP-) no momento RAD 1 foi de 98,0 e 97,3 e no momento RAD 2 foi de 97,6 e 99,1. Houve correlaÃÃo entre coeficientes da acuidade visual entre âSnellen e RAD 1â, âSnellen e RAD 2â, para os dois olhos (p = 0,0001). Na associaÃÃo (X2) encontrou-se um coeficiente de 151,90 (p = 0,0001) para RAD 1 e de 177,07 (p = 0,0001) para RAD 2; para o olho direito e para o esquerdo em RAD 1 foi de 147,75 (p = 0,0001) e de 199,69 (p = 0,0001) em RAD 2, no olho esquerdo. Para a anÃlise da concordÃncia em todos os casos encontrou-se um Alfa de Cronbach maior que 0,929. Os dados demonstram significÃncia entre o critÃrio padrÃo utilizado e a escala de figuras em anÃlise. Conforme a literatura, o modelo de validaÃÃo em tecnologia estabelece normas a serem cumpridas. A confecÃÃo de uma tabela de figuras regionalizada exige o cumprimento dos seguintes quesitos: uso da teoria de formaÃÃo da imagem para construÃÃo de escalas optomÃtricas: uso do sistema visual para caracterizar o aprendizado visual (passo 1); padronizaÃÃo da escala optomÃtrica como propriedade do sistema (passo 2); uso da dimensionalidade com base nos aspectos Ãptico-fisiolÃgicos (passo 3); e caracterizaÃÃo das definiÃÃes principais a serem seguidas na validaÃÃo de figuras e construÃÃo de optÃtipos (passo 4); demonstraÃÃo da operacionalizaÃÃo na elaboraÃÃo de escalas optomÃtricas (passo 5); anÃlise dos optÃtipos da escala de figuras (passo 6); planejamento da aplicaÃÃo na metodologia (passo 7); aplicaÃÃo e coleta para aferiÃÃo das alteraÃÃes oculares (passo 8); uso de tÃcnicas de validaÃÃo (passo 9); uso de tÃcnicas de precisÃo (passo 10) e consideraÃÃes finais (passo 11). As regras estabelecidas servem como ponto de partida para o desenvolvimento da tabela em cada regiÃo, pois cada uma deverà possuir suas caracterÃsticas prÃprias que devem ser respeitadas.

M.Sc. (Optometry) / The difference between objective automatic and subjective clinical refraction is studied using new statistical techniques. The question, by how much the two refraction techniques differ, is investigated by subtracting the subjective refraction finding from the auto refractory finding and then examining the distribution of the difference or excess as it will be called here. Computerized procedures were developed to automate mathematical and statistical methods of analysis. The methods were applied to two different samples: one of patients visiting an ordinary optometric practice (the clinical sample) and the other of children refracted in a screening program (the sample of school children) . The clinical sample, consisting of mainly older patients, is examined first. The difference between the autorefractor and subjective findings is studied and described. This difference could be used to compare different types of auto refractors assuming that the subjective refraction is correct. For the purpose of this study, however, the results of eight autorefractors are grouped together, combining left and right eyes, to serve as basis for studying the older population. The study shows that on the average there is no clinically significant excess. This means that there is on average no clinically significant difference between the automatic and clinical refraction for this population.

The goal of this bachelor thesis is a proposal design of optometric device for primary examination of eye vision, which should respect the functional requirements and conceptualize the technical and aesthetic aspects. The work includes a study of the current market situation and development of new technologies in the field. The proposal deals with an ergonomic design and issues.

Bakgrund: Visuell snö är ett perceptionsstörande neurooftalmologiskt tillstånd karakteriserat av bestående mikroskopiska flimrande prickar som täcker hela det bilaterala synfältet. Det kan liknas vid att titta genom en flimrande tv-skärm, eller Gaussiskt brus. Några etablerade riktlinjer för behandling finns inte för närvarande. Syfte: Denna litteraturstudie syftar till att undersöka tillgänglig litteratur rörande effekten av olika behandlingsalternativ för tillståndet visuell snö.  Metod: En sökning utfördes i sökmotorn PubMed den 20 mars 2023. Söksträngen som användes var “visual snow” OR “visual snow syndrome” AND “treatment”. Fler studier tillkom genom granskning av referenser. Begränsningar i urvalet baserades på relevans rörande behandling, samt en litteraturstudie utförd av Eren & Schankin publicerad 2020. Den här studien tar upp arbeten tillkomna därefter, totalt 8 artiklar utgivna mellan 2020-2022.  Resultat: Vår studie har lyckats identifiera behandlingsalternativ för visuell snö i form av neuro-optometrisk synträning, farmaceutika, kosttillskott, kiropraktik, filterglasögon, antikroppar, mydriatika, synstimuli, samt repetitiv transkraniell magnetstimulering. Samtliga studier utfördes på deltagare med bekräftad och diagnostiserad visuell snö, antingen som isolerat symptom, som del av Visual Snow Syndrome, eller som sekundärt tillstånd. Positiva behandlingssvar med partiell remission förekommer, samt enstaka fall av total remission. Samtliga inkluderade studier har sina begränsningar, en gemensam sådan är svårigheten att kvantifiera symptomen. Med hjälp av enkäter och symptomdagböcker har 7 av 8 studier visat på viss subjektiv effekt av behandling, av okänd magnitud.  Slutsats: Patofysiologin bakom visuell snö är ännu inte klarlagd. I dagsläget finns ingen generellt applicerbar behandling för visuell snö, men enstaka fall av total remission samt ett antal fall av partiell remission förekommer i litteraturen. Vid behandling av patienter med visuell snö bör hänsyn tas till individuella patienters förutsättningar, komorbiditet och tidigare prövad behandling. / Background: Visual snow is a neuro-ophthalmological perception disorder characterized by persistent microscopic flickering dots covering the bilateral field of vision. It can be described as looking through TV static, or Gaussian noise. There are currently no established guidelines regarding treatment. Purpose: This literature survey aimed to investigate available literature regarding the efficacy of different therapeutic approaches for the condition of visual snow.   Method: A search was performed in the PubMed search engine on March 20, 2023. The search string used was “visual snow” OR “visual snow syndrome” AND “treatment”. Further studies were added through references. Restrictions in article selection were based on relevance regarding treatment, as well as a review by Eren & Schankin published in 2020. This study covers subsequent articles, a total of 8 articles published between 2020-2022. Results: Our study has identified therapeutic approaches to visual snow in the form of neuro-optometric rehabilitation therapy, pharmaceuticals, nutraceuticals, chiropractic treatment, filter glasses, antibodies, mydriatics, visual stimuli, and repetitive transcranial magnetic stimulation. All participants had confirmed and diagnosed visual snow either as an isolated symptom, as part of Visual Snow Syndrome, or as a secondary condition. Positive responses with partial remission occur, as well as occasional total remissions. All included studies have some limitations, a common one being the difficulty in quantifying the symptoms. Using questionnaires and symptom diaries, 7 out of 8 studies have shown some subjective effect of treatment of unknown magnitude.  Conclusion: The pathophysiology behind visual snow is not yet fully understood. Currently, there is no generally applicable treatment for visual snow, but occasional cases of total remission and a number of cases of partial remission appear in the literature. When treating patients with visual snow, the individual patient’s conditions, comorbidity and previously tried treatment should be taken into account.