Vertex distance variability of the Vision-S™ 700 refractors in normal population / Variabilidade da distância vértice do refrator Vision-S™ 700 em uma população normal

ABSTRACT Objective: To study vertex-optical distance variation and estimate its impact on manifest refraction. Methods: Prospective study in a private clinic using the Vision-S™ 700 with five forehead positions. Forehead on the third position showed the closest vertex-optical distance of 12mm. Results: Analysis of 52 eyes from 26 patients revealed mean differences in vertex-optical distance of 12.25mm (right eye) and 11.75mm (left eye). A 2mm change in vertex-optical distance resulted in a 0.05D change for a 5D spherical equivalent and 0.20D for a 10D equivalent. Conclusion: Vertex-optical distance varies among patients and is influenced by forehead adjustment. These variations impact refraction accuracy and treatment evaluation. Adjusting the forehead to the third position on the Vision-S™ 700 is recommended.

RESUMO Objetivo: Estudar a variação da distância vértice-óptico, de acordo com o ajuste da testa, e estimar seu impacto na refração manifesta. Métodos: Estudo prospectivo realizado em clínica privada. A refração foi realizada utilizando cinco posições preestabelecidas com o Vision-Sa 700. A testa disposta na terceira posição apresentou distância vértice do refrator mais próxima de 12mm. Resultados: Foram analisados 52 olhos de 26 pacientes. A diferença média da distância vértice do refrator no olho direito foi de 12,25mm (variação de 11,50mm) e, no olho esquerdo, 11,75mm (variação de 12,00mm). O impacto foi de 2mm na distância vértice do refrator, fomentando em uma mudança de 0,05D para um equivalente esférico de 5D e 0,20D para um equivalente de 10D. Conclusão: A distância vértice do refrator varia entre pacientes, estando relacionada ao ajuste da testa. As variações afetam a precisão da refração, impactando no ajuste dos óculos, das lentes de contato e na avaliação pós-operatória de cirurgia refrativa. Sugerimos ajustar a posição da testa para terceira posição no Vision-S™ 700, se a distância vértice do refrator não for medida em todos os pacientes.

Spatial contrast sensitivity: effects of reliability, test-retest repeatability and sample size using the Metropsis software.

PURPOSE: The goals of the study were to further assess contrast sensitivity to (1) investigate the existence of monocular vs. binocular differences; (2) observe possible differences between sample sizes; (3) investigate the effects of test-retest repeatability. METHODS: Contrast sensitivity measurements were obtained by presenting eight horizontal sine-wave gratings (ranging from 0.2 to 20 cycles per degree). A three-up-one-down method was used to obtain thresholds with a criterion of 79.4% correct responses for each spatial frequency. The mean of 12 reversals was used for obtaining thresholds, and the two-alternative forced-choice method was used. Data were recorded in 55 naive observers from 20 to 45 years. All participants were free from identifiable ocular disease and had normal visual acuity. RESULTS: We observed the absence of differences on CSF for both monocular and binocular observers, as well as the absence of differences between large sample sizes. The latter investigation revealed a high degree of repeatability across time (baseline to 6 months later) with the higher test-retest for low and high spatial frequencies. CONCLUSIONS: Our results indicated that spatial contrast sensitivity measurements were little influenced by variables, such as binocular summation, eye dominance, sample size and time using the Metropsis test. The results obtained here have significance for basic and clinical vision science.

Da visão à cidadania: tipos de tabelas de avaliação funcional da leitura na educação especial / From vision to citizenship: types of tables to assess reading in special education

Resumo A importância da leitura já foi amplamente demonstrada ao longo do tempo e vem sendo mais profundamente compreendida e elucidada através de estudos científicos. No caso de pessoas com baixa visão, a leitura pode ser a garantia de acesso à educação e consequentemente à cidadania. Por isso, permitir boa capacidade de leitura tornou-se objeto de estudo de diversos pesquisadores. O desafio de garantir uma boa leitura é ainda maior no caso de pessoas portadoras de baixa visão, e frequentemente auxílios ópticos e tecnológicos são necessários para que a leitura se torne possível e seja fluida. Diversas tabelas, como a MNRead, Radner, Bailey-Lovie, entre outras, têm sido utilizadas para avaliar a capacidade de leitura, o tamanho mínimo de letra suficiente para a leitura fluente, e a velocidade máxima de leitura em palavras ou caracteres por minuto. Essas tabelas foram desenvolvidas e calibradas de acordo com normas internacionais, tornando-se padronizadas e adequadas para a aquisição de dados que poderão ser utilizados em pesquisas científicas reprodutíveis em qualquer parte do mundo. As tabelas possuem versões em diversas línguas, e a única tabela padronizada e traduzida para o português brasileiro disponível atualmente é a MNRead-P. Discutimos aqui as diferentes tabelas, a importância de sua calibração, e sua utilização na prática. As medidas obtidas com as tabelas de leitura são de grande importância para o planejamento do tratamento e acompanhamento de indivíduos com baixa visão, pois as comparações são feitas a partir de um parâmetro individual, entre as medidas do próprio indivíduo, em diferentes momentos, indicando melhora ou piora da qualidade de leitura. A alfabetização de indivíduos com deficiência visual é parte do exercício pleno de sua cidadania. A educação é a lente por meio da qual a pessoa é vista e enxerga a sociedade. Educar os portadores de deficiência é por si só uma forma de inclusão. Por isso, auxiliar os portadores de baixa visão pode ser um diferencial no seu desenvolvimento, permitindo a adequada composição do núcleo de identidade do indivíduo.

Abstract The importance of reading hability has already been greatly shown throughout time and has been studied and understood through scientific research. In the case of people with low vision, reading can be the guarantee of access to education and, consequently, to citizenship. Therefore, allowing good reading ability has become the object of study of several researchers. The challenge of ensuring good reading is even greater for people with low vision, and often optical and technological aids are needed to make reading possible and fluid. Several tables, such as MNRead, Radner, Bailey-Lovie, among others, have been used to evaluate reading ability, minimum letter size for fluent reading, and maximum reading speed in words or characters per minute. These tables have been developed and calibrated according to international standards, becoming standardized and suitable for the acquisition of data that can be used in reproducible scientific research anywhere in the world. The tables have versions in several languages, and the only table standardized and translated into Brazilian Portuguese currently available is MNRead-P. We discuss here the different tables, the importance of their calibration, and their practical use. The measurements obtained with the reading tables are of great importance for planning the treatment and follow-up of individuals with low vision, since the comparisons are made from an individual parameter, between the individual's measurements, at different moments, indicating improvement or worse reading quality. The literacy of visually impaired individuals is part of the full exercise of their citizenship. Education is the lens through which the person is seen and sees society. Educating people with disabilities is in itself a form of inclusion. Therefore, assisting low vision sufferers may be a differential in their development, allowing adequate composition of the individual's identity core.

Preverbal visual photo screening Project implementation in Portugal / Implementação de projeto de foto rastreio visual pré-verbal em Portugal

Abstract Purpose: To present the design and implementation of an amblyopia risk factors screening project, in a large based Portuguese population. Methods: Two referral centers have been enrolled to assess all children aged 2 under their direct referral area. The photoscreener used was PlusOptix ® A09. At this age, the cut-off defined for referral was: ≥1 Diopter (D) of anisometropia, ≥1.5D of astigmatism, ≥2D of myopia and ≥1.5D of hyperopia. The results were reported to a reading platform that allowed the ophthalmologist to see all exams, and provide timely appointment with a complete ophthalmologic assessment for those who needed. Results: A total of 2867 photo screens were made to the population eligible to both referral centers, which comprises a coverage rate of 55%. Out of 2611 children under one of the referral area, 53% (n=1395) adhered to the screening. Within these children, 17.5% (n=245) were referred and 15.3 % (n=214) appointments were performed. The comparison of refraction between PlusOptix ® and cycloplegic refraction showed a strong correlation regarding the sphere and cylinder values. From the 214 children observed in consultation, glasses were prescribed in 25.7% (n=55), corresponding to 3.9% of all screened children under one of the referral area. This screening method showed a positive predictive value of 58.4%. Conclusion: This screening program may be highly relevant to eradicate untreated amblyopia from our population. The results may lead to the implementation of this project to the whole country.

Resumo Objetivo: Apresentação da implementação de um projeto de rastreio de fatores de risco de ambliopia, numa população alargada portuguesa. Métodos: dois centros de referência foram selecionados para avaliar todas as crianças de 2 anos, na sua área de referenciação direta. Para o foto rastreio foi utilizado o PlusOptix ® A09. Nesta idade, os valores definidos para referenciação foram: ≥1 Dioptria (D) de anosimetropia, ≥1.5 D de astigmatismo, ≥2 D de miopia e ≥1.5 D de hipermetropia. Os resultados foram reportados a uma plataforma de leitura que permitiu ao oftalmologista ver todos os exames e providenciar uma consulta oportuna com uma avaliação oftalmológica completa para aqueles que precisavam. Resultados: Foram realizados 2867 foto rastreios na população elegível para ambos os centros de referência, perfazendo uma taxa de cobertura de 55%. Das 2611 crianças sob uma área de referência, 53% (n = 1395) aderiram ao rastreio. Dentro desse grupo, 17,5% (n = 245) foram referenciadas e 15,3% (n = 214) consultas foram realizadas. Verificou-se uma forte correlação entre a refração do PlusOptix® e a refração cicloplégica. Das 214 crianças observadas em consulta, foram prescritos óculos em 25,7% (n = 55), correspondendo a 3,9% de todas as crianças sob uma área de referência. Este método de triagem mostrou um valor preditivo positivo de 58,4%. Conclusão: Este programa de rastreio pode ser altamente relevante para erradicar a ambliopia não tratada na nossa população. Os resultados podem levar à implementação deste projeto em todo o país.

Repeatability of contrast sensitivity testing in patients with age-related macular degeneration, glaucoma, and cataract.

PURPOSE:: To analyze the intrasession and intersession repeatability of contrast sensitivity (CS) measurements in patients with glaucoma, cataract, or age-related macular degeneration (AMD) and healthy controls. METHODS:: CS measurements were performed using the OPTEC-Functional Vision Analyzer (FVA), which uses a standardized and closed (view-in) system. Measurements for patients with glaucoma, cataract, or AMD and healthy controls were repeated within 30 minutes (intrasession) and during two sessions (intersession), separated by one week to one month. Test-retest reliability and correlation were measured using the intraclass correlation coefficient (ICC) and coefficient of repeatability (COR). RESULTS:: Ninety subjects (90 eyes) with visual acuity of 0.17 logMAR or higher in the cataract group or 0.00 logMAR in the other groups were included. During the first session, the ICC values were 0.87, 0.90, 0.76, and 0.69, and COR values were 0.24, 0.20, 0.38, and 0.25 for the control, glaucoma, cataract, and AMD groups, respectively. The reliability scores significantly improved during the second session, except in the glaucoma group. There was an acceptable floor effect and no ceiling effect at higher frequencies in the glaucoma and AMD groups. CONCLUSION:: In subjects with good visual acuity, the FVA system is useful for evaluating CS and demonstrates good repeatability, as shown by ICC and COR. Because there is no ceiling effect, this system is beneficial for evaluation of early changes in CS, particularly in patients with glaucoma or AMD.

Repeatability of contrast sensitivity testing in patients with age-related macular degeneration, glaucoma, and cataract / Reprodutibilidade dos escores de sensibilidade ao contraste em pacientes com degeneração macular relacionadas à idade, glaucoma e catarata

ABSTRACT Purpose: To analyze the intrasession and intersession repeatability of contrast sensitivity (CS) measurements in patients with glaucoma, cataract, or age-related macular degeneration (AMD) and healthy controls. Methods: CS measurements were performed using the OPTEC-Functional Vision Analyzer (FVA), which uses a standardized and closed (view-in) system. Measurements for patients with glaucoma, cataract, or AMD and healthy controls were repeated within 30 minutes (intrasession) and during two sessions (intersession), separated by one week to one month. Test-retest reliability and correlation were measured using the intraclass correlation coefficient (ICC) and coefficient of repeatability (COR). Results: Ninety subjects (90 eyes) with visual acuity of 0.17 logMAR or higher in the cataract group or 0.00 logMAR in the other groups were included. During the first session, the ICC values were 0.87, 0.90, 0.76, and 0.69, and COR values were 0.24, 0.20, 0.38, and 0.25 for the control, glaucoma, cataract, and AMD groups, respectively. The reliability scores significantly improved during the second session, except in the glaucoma group. There was an acceptable floor effect and no ceiling effect at higher frequencies in the glaucoma and AMD groups. Conclusion: In subjects with good visual acuity, the FVA system is useful for evaluating CS and demonstrates good repeatability, as shown by ICC and COR. Because there is no ceiling effect, this system is beneficial for evaluation of early changes in CS, particularly in patients with glaucoma or AMD.

RESUMO Objetivo: Analisar a reprodutibilidade intrassessão e intersessão das medidas de sensibilidade ao contraste (CS) em pacientes com degeneração macular relacionada à idade (AMD), glaucoma e catarata. Método: As medidas de CS foram feitas pelo OPTEC-Funcional Visão Analyzer (FVA), que utiliza um sistema padronizado e fechado de avaliação da acuidade visual. Medidas em pacientes com AMD, glaucoma, catarata e nos controles saudáveis foram repetidas no prazo de 30 minutos (intrassessão) em duas visitas (intersessão), separadas por uma semana a um mês. A confiabilidade e correlação teste-reteste foram calculados por meio do coeficiente de correlação intraclasse (ICC) e coeficiente de reprodutibilidade (COR). Resultados: Noventa olhos de 90 indivíduos foram recrutados com acuidade visual de 0,17 logMAR ou melhor em catarata e 0,00 logMAR nos outros grupos. A confiabilidade da CS na primeira visita dos grupos normal, glaucoma, catarata e AMD foram, respectivamente, ICC 0,87; 0,90; 0,76; 0,69, e COR 0,24; 0,20; 0,38; 0,25. Os índices de confiabilidade foram significativamente melhorados nas segundas visitas, exceto no grupo glaucoma. Houve um efeito chão aceitável e nenhum efeito teto em frequências mais altas nos grupos glaucoma e AMD. Conclusões: Em indivíduos com boa acuidade visual, o sistema FVA de avaliação da CS é útil e apresenta boa confiabilidade, como mostrado pelas análises de ICC e COR. Por não apresentar efeito teto, este sistema parece ser benéfico para a avaliação das alterações precoces de CS, especialmente no glaucoma e AMD.

Comparison between refraction measured by Spot Vision Screening™ and subjective clinical refractometry.

OBJECTIVE: The purpose of this study was to evaluate the accuracy of Spot Vision Screening™ as an autorefractor by comparing refraction measurements to subjective clinical refractometry results in children and adult patients. METHODS: One-hundred and thirty-four eyes of 134 patients were submitted to refractometry by Spot and clinical refractometry under cycloplegia. Patients, students, physicians, staff and children of staff from the Hospital das Clínicas (School of Medicine, University of São Paulo) aged 7-50 years without signs of ocular disease were examined. Only right-eye refraction data were analyzed. The findings were converted in magnitude vectors for analysis. RESULTS: The difference between Spot Vision Screening™ and subjective clinical refractometry expressed in spherical equivalents was +0.66±0.56 diopters (D), +0.16±0.27 D for the vector projected on the 90 axis and +0.02±0.15 D for the oblique vector. CONCLUSIONS: Despite the statistical significance of the difference between the two methods, we consider the difference non-relevant in a clinical setting, supporting the use of Spot Vision Screening™ as an ancillary method for estimating refraction.

Comparison between refraction measured by Spot Vision ScreeningTM and subjective clinical refractometry

OBJECTIVE: The purpose of this study was to evaluate the accuracy of Spot Vision ScreeningTM as an autorefractor by comparing refraction measurements to subjective clinical refractometry results in children and adult patients. METHODS: One-hundred and thirty-four eyes of 134 patients were submitted to refractometry by Spot and clinical refractometry under cycloplegia. Patients, students, physicians, staff and children of staff from the Hospital das Clínicas (School of Medicine, University of São Paulo) aged 7-50 years without signs of ocular disease were examined. Only right-eye refraction data were analyzed. The findings were converted in magnitude vectors for analysis. RESULTS: The difference between Spot Vision ScreeningTM and subjective clinical refractometry expressed in spherical equivalents was +0.66±0.56 diopters (D), +0.16±0.27 D for the vector projected on the 90 axis and +0.02±0.15 D for the oblique vector. CONCLUSIONS: Despite the statistical significance of the difference between the two methods, we consider the difference non-relevant in a clinical setting, supporting the use of Spot Vision ScreeningTM as an ancillary method for estimating refraction.

Teller test with functional vision evaluation in children with low vision / Teste com Cartões de Teller e avaliação da visão funcional em crianças com baixa visão

ABSTRACT Objective: To know the effectiveness of Teller card test along with the functional vision evaluation in low vision preschool children presenting normal or delayed development. Methods: Transversal study comprising patients from the children visual stimulation Ambulatory Service of the Faculty of Medical Sciences, University of Campinas Teaching Hospital, Campinas (SP)(FCM/HC/ Unicamp). The best corrected visual acuity was obtained using Teller cards and functional vision evaluation, independent from the child development. Results: From a total of 143 evaluated children, 65% did not respond to the Teller card test, only to, the functional vision evaluation. Among 143 children, 99 (70%) presented development delay and 44 (30%), normal development. Conclusion: The Teller card test was not enough to evaluate the children visual acuity with development delays, since more than half of them were not responsive to it, making it necessary that they were submitted to a complementary functional visual evaluation.

Objetivo: Conhecer a eficácia do teste com Cartões de Teller em complemento a avaliação da visão funcional em crianças préescolares com baixa visão e desenvolvimento normal ou atrasado. Métodos: Estudo transversal em pacientes do ambulatório de estimulação visual infantil do Hospital de Clínicas da Faculdade de Ciências Médicas da Universidade Estadual de Campinas (HC/ FCM/Unicamp). A acuidade visual com a melhor correção óptica foi medida com Cartões de Teller e avaliação da visão funcional, independente do desenvolvimento da criança. Resultados: De um total de 143 crianças avaliadas 65% não responderam ao teste de Teller, porém, em complemento à avaliação da visão funcional pôde ser conhecida a acuidade visual das mesmas. Dentre as 143 crianças, 99 (70%) apresentaram atraso no desenvolvimento e 44 (30%) desenvolvimento normal. Conclusão: O Teste com Cartões de Teller para se conhecer a acuidade visual de crianças com atraso em seu desenvolvimento não se apresentou suficiente, pois mais da metade das crianças avaliadas não foi responsiva ao mesmo, necessitando de complementação de avaliação da visão funcional para a medida da acuidade visual.

Assessment of visual acuity in patients with dementia using teller acuity cards.

UNLABELLED: Assessing visual acuity in adults or children at an eye exam is generally simple and has become routine procedure in clinical practice. However, depending on severity and stage of clinical evolution, elderly patients with dementia may experience difficulties performing tests of recognition, because these tests depend not only on perception, but also cognition and its response. Testing visual functions in such cases represents a challenge in clinical practice and a task that requires proper skills and methods. PURPOSE: To evaluate the effectiveness of objective measurement of visual acuity by behavioral methods using Teller acuity cards in elderly patients with dementia, diagnosed with presumed Alzheimer's disease. METHODS: The visual acuity of 20 elderly patients diagnosed with presumed Alzheimer's disease and 24 controls with no cognitive impairment was assessed using the recognition method (Lea symbols) and resolution grating method (Teller acuity cards). RESULTS: The results found for the two methods were statistically well correlated. CONCLUSION: An alternative method for assessing visual function in patients with Alzheimer's disease, even at early stages, is of utmost relevance not only for monitoring disease progression, but also to quantitatively determine the impact of eye treatments and determine potential visual loss, guiding optical and non-optical strategies for optimal use of residual vision.

Volume visualization using a spatially aware mobile display device.

Volume visualization is a difficult three-dimensional task and a significant amount of research is devoted to the development of a suitable computer input device for it. Most of the proposed models use fixed displays, thus rendering extracted slices in orientations unrelated to their real locations within the volume. We present a new device which takes a different approach, as it leaves the volume in a fixed location and demands the user to change his or her posture to explore it from different angles. To implement this, we built a prototype based on a mobile display equipped with sensors that allows it to track its position, which is related to the location of the slice plane within the volume. Therefore, the user can manipulate this plane by displacing and rotating the display, which is a very intuitive method with minimum learning time. Furthermore, the postural changes required to use the device add a new channel of feedback, which effectively helps to reduce the cognitive load imposed on the user. We built a prototype device and tested it with two groups of volunteers who were asked to use it in a medical imaging application. Statistical analysis of the results shows that explorations made with the proposed device were considerably faster with no penalty in precision. We believe that, with further work, the proposed device can be developed into an useful tool for radiology and neurosurgery.

[Vision measurement in candelas: description of a psychophysical technique to quantify luminous intensity]. / Medida da visão em candelas: description of a psychophysical technique to quantify luminous intensity.

PURPOSE: To develop a method and a device for vision measurement in candela (cd). Vision measurement studies are important to all visual sciences. METHODS: It is a theoretical and experimental study. The details of psychophysical method and device calibration were described. Preliminary tests were performed on volunteers. RESULTS: It is a simple psychophysical test and results are expressed in International System of Units. With this technical description it will be possible to reproduce the experiment in others research centers. CONCLUSION: The results measured in luminous intensity (cd) are an option for visual studies. These results allow to extrapolate measurements for mathematical models and to simulate data for individual aberrometry effects.

Medida da visão em candelas: description of a psychophysical technique to quantify luminous intensity / descrição de uma técnica psicofísica para quantificar intensidade luminosa / Vision measurement in candelas

OBJETIVO: Desenvolver um método e um dispositivo para quantificar a visão em candela (cd). Os estudos de medida da visão são importantes para todas as ciências visuais. MÉTODOS: É um estudo teórico e experimental. Foram descritos os detalhes do método psicofísico e da calibração do dispositivo. Foram realizados testes preliminares em voluntários. RESULTADOS: É um teste psicofísico simples e com resultado expresso em unidades do sistema internacional de medidas. Com a descrição técnica será possível reproduzir o experimento em outros centros de pesquisa. CONCLUSÃO: Os resultados aferidos em intensidade luminosa (cd) são uma opção para estudo visual. Esses resultados possibilitarão extrapolar medidas para modelos matemáticos e para simular efeitos individuais com dados aberrométricos.

PURPOSE: To develop a method and a device for vision measurement in candela (cd). Vision measurement studies are important to all visual sciences. METHODS:It is a theoretical and experimental study. The details of psychophysical method and device calibration were described. Preliminary tests were performed on volunteers. RESULTS:It is a simple psychophysical test and results are expressed in International System of Units. With this technical description it will be possible to reproduce the experiment in others research centers. CONCLUSION: The results measured in luminous intensity (cd) are an option for visual studies. These results allow to extrapolate measurements for mathematical models and to simulate data for individual aberrometry effects.

[Reliability of predictable postoperative visual acuity of cataracts as measured by Heine Lambda 100 retinometer preoperatively]. / Confiabilidade da previsão da acuidade visual pós-operatória de catarata mediante medição da acuidade visual pré-operatória utilizando o retinômetro Heine Lambda 100.

PURPOSE: To assess the relationship between potential visual acuity obtained before cataract surgery using Heine Lambda 100 retinometer with best corrected visual acuity 3 months postoperatively, as well as its correlation with the morphological pattern of the dominant cataract and the intensity of nuclear opacification. METHODS: Prospective study executed in the Ophthalmology Hospital Laser Vision in Santos of 121 eyes of 70 patients who underwent cataract surgery (phacoemulsification with intraocular lens implantation), from April to July, 2009. In the preoperative period, Heine retinometer test was performed under mydriasis and its results were compared to postoperative best corrected visual acuity three months after surgery and correlated with the morphological classification of cataracts, being considered a satisfactory result those who did not vary more than two lines in Snellen chart. RESULTS: The satisfactory cases found in our study were 86.78%, with results of visual acuity with Heine retinometer equal to the postoperative visual acuity in 34.7% of the cases. Predominant nuclear opacity N1+ has a higher reliability than N2+ and N3+ (50%, 31.3% and 26.7%, respectively). Regarding all studied eyes, statistical significance was noted (p<0.0001). CONCLUSION: In most cases Heine retinometer underestimated or maintained best corrected visual acuity 3 months postoperatively in patients who underwent cataract surgery. With respect to the morphological classification of cataracts, the higher the opacity of the nuclear lens, the greater the visual acuity underestimation.

Confiabilidade da previsão da acuidade visual pós-operatória de catarata mediante medição da acuidade visual pré-operatória utilizando o retinômetro Heine Lambda 100 / Reliability of predictable postoperative visual acuity of cataracts as measured by Heine Lambda 100 retinometer preoperatively

Objetivo: Utilizar o retinômetro de Heine Lambda 100 para avaliar a relação da acuidade visual obtida no pré-operatório de cirurgia de catarata com a acuidade visual obtida 3 meses no pós-operatório com correção óptica, bem como, sua correlação com a classificação morfológica dominante da catarata e com a intensidade da opacificação quando do tipo nuclear. Métodos: Trata-se de um estudo prospectivo realizado no Hospital Oftalmológico Visão Laser, em Santos, envolvendo 121 olhos de 70 pacientes avaliados de abril a julho 2009, submetidos à cirurgia de catarata sob a técnica de facoemulsificação com implante de lente intraocular. No período pré-operatório, foi realizado o retinômetro de Heine sob midríase e seu resultado foi comparado à melhor acuidade visual pós-operatória do terceiro mês e correlacionado com a classificação morfológica da catarata, quando do tipo nuclear, sendo denominado satisfatório aquele resultado que não variou mais do que duas linhas na tabela de Snellen. Resultados: Os resultados satisfatórios em nosso estudo foram de 86,78 por cento, apresentando resultados de acuidade visual com retinômetro de Heine igual ao resultado da acuidade visual pós-operatória em 34,7 por cento. A opacidade predominantemente nuclear N1+ tem um porcentual de acerto maior do que N2+ e N3+ (50 por cento, 31,3 por cento e 26,7 por cento, respectivamente). Em relação ao total de olhos, observamos um teste extremamente significante (p<0,0001). Conclusão: O retinômetro de Heine hipoestimou ou manteve a acuidade visual pós-operatória corrigida após 3 meses dos pacientes submetidos à facectomia, na maioria dos casos. Ao correlacionar com a classificação morfológica da catarata, observamos que, quanto maior a opacidade do cristalino do tipo nuclear, maior a hipoestimação da acuidade visual.

Purpose: To assess the relationship between potential visual acuity obtained before cataract surgery using Heine Lambda 100 retinometer with best corrected visual acuity 3 months postoperatively, as well as its correlation with the morphological pattern of the dominant cataract and the intensity of nuclear opacification. Methods: Prospective study executed in the Ophthalmology Hospital Laser Vision in Santos of 121 eyes of 70 patients who underwent cataract surgery (phacoemulsification with intraocular lens implantation), from April to July, 2009. In the preoperative period, Heine retinometer test was performed under mydriasis and its results were compared to postoperative best corrected visual acuity three months after surgery and correlated with the morphological classification of cataracts, being considered a satisfactory result those who did not vary more than two lines in Snellen chart. Results: The satisfactory cases found in our study were 86.78 percent, with results of visual acuity with Heine retinometer equal to the postoperative visual acuity in 34.7 percent of the cases. Predominant nuclear opacity N1+ has a higher reliability than N2+ and N3+ (50 percent, 31.3 percent and 26.7 percent, respectively). Regarding all studied eyes, statistical significance was noted (p<0.0001). Conclusion: In most cases Heine retinometer underestimated or maintained best corrected visual acuity 3 months postoperatively in patients who underwent cataract surgery. With respect to the morphological classification of cataracts, the higher the opacity of the nuclear lens, the greater the visual acuity underestimation.

Fidelidade do "potential acuity meter" (PAM) no prognóstico da acuidade visual pós-operatória de cirurgia de catarata / Fidelity of the potential acuity meter in the postoperative visual acuity of cataract surgery

OBJETIVO: Avaliar a relação da acuidade visual (AV) obtida pelo "potential acuity meter" (PAM) no pré-operatório de cirurgia de catarata com a acuidade visual obtida no pós-operatório, bem como, sua correlação com a classificação morfológica dominante da catarata. MÉTODOS: Trata-se de um estudo prospectivo realizado no setor de Catarata do Centro de Estudos do Hospital Monumento envolvendo 63 olhos de 45 pacientes avaliados de julho a setembro de 2006, submetidos à cirurgia de catarata sob a técnica de facoemulsificação com implante de lente intra-ocular, sendo posteriormente excluído 1 olho. No período pré-operatório, foi realizado o PAM sob midríase e seu resultado foi comparado à melhor acuidade visual pós-operatória do terceiro mês e correlacionado com a classificação morfológica da catarata, sendo denominado satisfatório aquele resultado que não variou mais do que duas linhas na tabela de Snellen. RESULTADOS: A média de idade foi de 45,3 anos com média da acuidade visual obtida pelo PAM de 0,64 logMAR. No terceiro mês pós-operatório, a média da melhor acuidade visual corrigida (MAVC) foi de 0,09 logMAR. O PAM hiperestimou o resultado da MAVC em 8 olhos (13 por cento), hipoestimou em 41 olhos (66 por cento) e nos 13 olhos restantes (21 por cento), as acuidades foram idênticas. Este apresentou uma fidelidade inversamente proporcional à intensidade de opacidade do cristalino no caso da catarata nuclear (1+ com 75,5 por cento e 4+ com 33,3 por cento), entretanto esta acurácia foi maior nos casos de subcapsular posterior (85,7 por cento). CONCLUSÃO: O PAM hipoestimou ou manteve da acuidade visual na maioria dos casos (87 por cento). Apresentou uma fidelidade inversamente proporcional à intensidade de opacidade do cristalino no caso da catarata nuclear, 1+ com 75,5 por cento e 4+ com 33,3 por cento; entretanto esta acurácia foi maior nos casos de subcapsular posterior (85,7 por cento).

PURPOSE: To evaluate the correlation between the preoperative visual acuity (VA) obtained by the potential acuity meter (PAM) and the postoperative VA in a patient submitted to cataract surgery, as well as its correlation with the dominant morphologic classification of the cataract. METHODS: This is a prospective study performed at the Hospital Monumento Study Center. Sixty-three eyes of 45 patients submitted to phacoemulsification with intraocular lens implantation were enrolled in this study and 1 eye had been excluded. Besides the complete examination in the preoperative period, PAM was used and its results were compared with the VA at the third postoperative month and correlated with the dominant morphologic cataract classification. The result was called satisfactory when the variation was equal to or less than two lines at the Snellen chart. We transformed the AV into logMAR for comparison with the literature. RESULTS: The mean age was 45.3 years with a mean VA of 0.64 logMAR by the PAM. At the third postoperative month, the mean best corrected visual acuity (BCVA) was 0.09 logMAR. The PAM overestimated the BCVA in 8 eyes (13 percent), underestimated it in 41 eyes (66 percent) and in 13 eyes (21 percent) the BCVA were the same. The satisfactory results regarding nuclear cataract were reduced in cases of higher density (1+/4 with 75.5 percent e 4+/4 with 33.3 percent) and increased in the posterior subcapsular cataracts (85.7 percent). CONCLUSION: PAM revealed an underestimation or maintenance of the BCVA in most cases (87 percent). Its fidelity was inversely proportional in the nuclear cataracts (1+/4 with 75.5 percent e 4+/4 with 33.3 percent) and higher in the posterior subcapsular cataracts.

[Vision measurement and psychophysical tests]. / Medida da visão e testes psicofísicos.

Vision measurement is the basis for the study and standardization of visual sciences. Measurement of visual acuity has great value for research and for clinical practice. This paper (1) reviews the fundamental concepts to understand visual sense and the measuring units; (2) presents the fundamental limits to visual performance and the principles of aberration measurement of the eye; and (3) discusses methods for measuring and classifying vision with new technologies.

Medida da visão e testes psicofísicos / Vision measurement and psychophysical tests

A medida da visão é a base para o estudo e a padronização das ciências visuais. A medida da acuidade visual tem grande importância tanto para a pesquisa como para a prática clínica. Esta revisão bibliográfica (1) revê os conceitos fundamentais para compreender o sentido visual e as unidades de medida; (2) apresenta os limites fundamentais ao desempenho visual e os princípios das medidas da aberração ocular; e (3) discute métodos para medir e classificar a visão com novas tecnologias.

Vision measurement is the basis for the study and standardization of visual sciences. Measurement of visual acuity has great value for research and for clinical practice. This paper (1) reviews the fundamental concepts to understand visual sense and the measuring units; (2) presents the fundamental limits to visual performance and the principles of aberration measurement of the eye; and (3) discusses methods for measuring and classifying vision with new technologies.

[Fidelity of the potential acuity meter in the postoperative visual acuity of cataract surgery]. / Fidelidade do "potential acuity meter" (PAM) no prognóstico da acuidade visual pós-operatória de cirurgia de catarata.

PURPOSE: To evaluate the correlation between the preoperative visual acuity (VA) obtained by the potential acuity meter (PAM) and the postoperative VA in a patient submitted to cataract surgery, as well as its correlation with the dominant morphologic classification of the cataract. METHODS: This is a prospective study performed at the Hospital Monumento Study Center. Sixty-three eyes of 45 patients submitted to phacoemulsification with intraocular lens implantation were enrolled in this study and 1 eye had been excluded. Besides the complete examination in the preoperative period, PAM was used and its results were compared with the VA at the third postoperative month and correlated with the dominant morphologic cataract classification. The result was called satisfactory when the variation was equal to or less than two lines at the Snellen chart. We transformed the AV into logMAR for comparison with the literature. RESULTS: The mean age was 45.3 years with a mean VA of 0.64 logMAR by the PAM. At the third postoperative month, the mean best corrected visual acuity (BCVA) was 0.09 logMAR. The PAM overestimated the BCVA in 8 eyes (13%), underestimated it in 41 eyes (66%) and in 13 eyes (21%) the BCVA were the same. The satisfactory results regarding nuclear cataract were reduced in cases of higher density (1+/4 with 75.5% e 4+/4 with 33.3%) and increased in the posterior subcapsular cataracts (85.7%). CONCLUSION: PAM revealed an underestimation or maintenance of the BCVA in most cases (87%). Its fidelity was inversely proportional in the nuclear cataracts (1+/4 with 75.5% e 4+/4 with 33.3%) and higher in the posterior subcapsular cataracts.

A technique to compensate the eye movement in dark adaptometry tests.

This paper describes a new technique to compensate the eye movements in dark adaptometry tests. The instrument is controlled by a personal computer and can be used in the investigation of several retinal diseases. The stimulus is delivered to the eye through the modified optics of a fundus camera using two light-channels: one for the stimulus presentation, and other for retinal visualization. Infrared images of the fundus are displayed on a video monitor and the stimulus position can be compensated in real time. These modifications provide the advantages of continuous monitoring of fixation and visualization of the retinal regions, thereby increasing the accuracy of dark adaptometry in patients with fixation problems.