Comparison of the effects of different chromatic lights on accommodative response and microfluctuation in myopes and emmetropes / 中华实验眼科杂志

Objective:To explore the effects of conflicting stimuli generated by different chromatic lights on visual display terminal (VDT) on accommodative response and microfluctuation of myopes and emmetropes, and to investigate the possible relationship between chromatic light, accommodation and the development and progression of myopia.Methods:A non-randomized controlled trial was conducted.Forty-one subjects aged 22 to 30 years old were enrolled, including 19 emmetropes in emmetropic group and 22 myopes in myopic group.The subjects had the normal color vision and no ocular organic diseases.The interventions were screens of different colors.There were 7 chromatic light conditions, including 3 monochromatic lights (red, green, blue), 3 bichromatic lights (red+ green, red+ blue, green+ blue) and 1 polychromatic light (white=red+ green+ blue). Subjects were asked to look at a black E target on a VDT at a distance of 33 cm for more than 20 seconds.The background color of the VDT was changed randomly in the 7 chromatic light conditions.The accommodative responses were recorded with the Grand Seiko WAM-5500 automatic infrared refractor every 0.2 seconds and the accommodative microfluctuation was calculated as the standard deviation of the accommodative response.Accommodative response and accommodative microfluctuation under different chromatic light conditions were compared.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committee of the First Affiliated Hospital, Zhejiang University School of Medicine (No.2019-1564). Written informed consent was obtained from each subject.Results:No statistically significant difference was found in the accommodative response between the two groups ( Fgroup=2.626, P=0.113). There was a statistically significant difference under different chromatic light conditions between the two groups ( Flight=39.070, P<0.01). There were similar trends in the effects of various color lights in both groups, with the largest accommodative response under monochromatic red light, followed by the bichromatic light containing red light, and then the smallest accommodative response under monochromatic blue light, and the differences were statistically significant (all at P<0.05). The accommodative microfluctuations under red, green, blue, red+ blue, red+ green, blue+ green and white light conditions were (0.142±0.033), (0.128±0.038), (0.131±0.043), (0.139±0.039), (0.127±0.034), (0.131±0.043) and (0.139±0.042)D in emmetropic group, and (0.178±0.043), (0.164±0.043), (0.159±0.039), (0.174±0.042), (0.166±0.036), (0.159±0.031) and (0.174±0.035)D in myopic group, respectively, showing statistically significant differences between them ( Fgroup=12.146, P<0.01; Flight=2.782, P<0.05). The accommodative microfluctuations under the 7 light conditions were higher in myopic group than in emmetropic group, and the differences were statistically significant (all at P<0.05). In myopes, the accommodative microfluctuation was the largest under red light, which was significantly larger than that under blue light, and was the smallest under blue+ green light (all at P<0.05). There was no significant difference in the accommodative microfluctuation between bichromatic light and its two monochromatic lights, or between the polychromatic light (white light) and its three monochromatic lights (all at P>0.05). There was no significant effect of various chromatic lights on the accommodative microfluctuation in emmetropic group (all at P>0.05). Conclusions:The accommodative microfluctuation is greater in myopes than in emmetropes.The stimuli produced by long-wavelength light cause larger accommodative microfluctuation, while conflicting stimuli generated by different chromatic lights do not increase accommodative microfluctuation.

Accommodative amplitudes and high-order aberrations in patients with multiple sclerosis with optic nerve ınvolvement / Amplitudes de acomodação e aberrações de alta ordem em pacientes com esclerose múltipla com envolvimento do nervo óptico

ABSTRACT Purpose: This study aimed to investigate and compare the changes in corneal aberrations and accommodative amplitudes between patients with multiple sclerosis and normal individuals. Methods: We included 20 patients who were previously diagnosed with multiple sclerosis with optic nerve involvement (multiple sclerosis group) and 20 healthy sex- and age-matched individuals (control group). We only selected those who were under 40 years old because accommodation in individuals over 40 years old significantly deteriorates. We measured the accommodative amplitude in diopters by minus lens test and evaluated the higher-order aberrations by using the iDesign aberrometer. Then, we compared the accommodative amplitude and the root mean square of higher-order aberrations between the groups. Results: The mean age of the multiple sclerosis and control groups were 35.25 ± 4.52 and 32.28 ± 6.83 years, respectively (p=0.170). The accommodative amplitude was 4.05 ± 1.25 D in the multiple sclerosis group and 6.00 ± 1.03 D in the control group, with a statistically significant difference (p<0.001). Meanwhile, the root mean square of higher-order aberrations was not significantly different between the groups (multiple sclerosis group, 0.44 ± 0.22; control group, 0.43 ± 0.10, p<0.824). Moreover, aberration changes had no statistically significant differences between the two groups at baseline and at 5 D stimulus. Conclusions: The accommodative amplitude was decreased in patients with multiple sclerosis, suggesting the possible cause of transient visual impairments in these patients. However, this accommodative amplitude did not demonstrate a significant difference in terms of higher-order aberration change during accommodation between such patients and the controls.

RESUMO Objetivo: Investigar se as aberrações da córnea e as amplitudes de acomodação alteram mais em pacientes com esclerose múltipla do que em populações normais. Métodos: Vinte pacientes previamente diagnosticados com esclerose múltipla com envolvimento do nervo óptico (grupo com eslerose múltipla) e 20 indivíduos saudáveis pareados por sexo e idade (grupo controle) foram incluídos no estudo. Pacientes com menos de 40 anos de idade foram incluídos em ambos os grupos devido à deterioração significativa de acomodação em pacientes com mais de 40 anos de idade. Para cada participante, a amplitude de acomodação foi medida em dioptrias pelo teste de lentes negativas e as aberrações de alta ordem foram avaliadas com o aberrômetro iDesign. Em seguida, a amplitude de acomodação e a média da raiz quadrada de aberrações de alta ordem foram comparadas entre os grupos. Resultados: As médias da idade dos grupos com esclerose múltipla e controle foram 35,25 ± 4,52 anos e 32,28 ± 6,83 anos, respectivamente (p=0,170). A amplitude de acomodação foi de 4,05 ± 1,25 D no grupo com esclerose múltipla e 6,00 ± 1,03 D no grupo controle. A diferença entre os com esclerose múltipla e o grupo controle foi estatisticamente significativa (p<0, 001). A média da raiz quadrada das aberrações de alta ordem não foi significativamente diferente entre os grupos (com esclerose múltipla, 0,44 ± 0,22; controle, 0,43 ± 0,10, p<0,824). Não houve diferenças estatisticamente significativas entre os grupos em termos de alterações de aberrações entre a linha de base e o estímulo 5 D. Conclusões: Este estudo mostra que a amplitude de acomodação diminuiu em pacientes com esclerose múltipla. Portanto, esses resultados podem causar possíveis razões de deficiências visuais transitórias em pacientes com esclerose múltipla. No entanto, esta diferença de amplitude de acomodação não fez uma diferença significativa entre os grupos quanto à alteração das aberrações de alta ordem durante a acomodação.

The effects of pharmacological accommodation and cycloplegia on axial length and choroidal thickness / Efeitos da acomodação farmacológica e da cicloplegia no comprimento axial e na espessura da coroide

ABSTRACT Purpose: To investigate the effects of pharmacological accommodation and cycloplegia on ocular measurements. Methods: Thirty-three healthy subjects [mean (±SD) age, 32.97 (±5.21) years] volunteered to participate in the study. Measurement of the axial length, macular and choroidal thickness, refractive error, and corneal topography, as well as anterior segment imaging, were performed. After these procedures, pharmacological accommodation was induced by applying pilocarpine eye drops (pilocarpine hydrochloride 2%), and the measurements were repeated. The measurements were repeated again after full cycloplegia was induced using cyclopentolate eye drops (cyclopentolate hydrochloride 1%). The correlations between the measurements were evaluated. Results: A significant increase in subfoveal choroidal thickness after applying 2% pilocarpine was identified (without the drops, 319.36 ± 90.08 µm; with pilocarpine instillation, 341.60 ± 99.19 µm; with cyclopentolate instillation, 318.36 ± 103.0 µm; p<0.001). A significant increase in the axial length was also detected (without the drops, 23.26 ± 0.83 mm; with pilocarpine instillation, 23.29 ± 0.84 mm; with cyclopentolate instillation, 23.27 ± 0.84 mm; p=0.003). Comparing pharmacological accommodation and cycloplegia revealed a significant difference in central macular thickness (with pilocarpine instillation, 262.27 ± 19.34 µm; with cyclopentolate instillation, 265.93 ± 17.91 µm; p=0.016). Pilocarpine-related miosis (p<0.001) and myopic shift (p<0.001) were more severe in blue eyes vs. brown eyes. Conclusion: Pharmacological accommodation may change ocular measurements, such as choroidal thickness and axial length. This condition should be considered when performing ocular measurements, such as intraocular lens power calculations.(AU)

RESUMO Objetivo: Investigar os efeitos da acomodação farmacológica e da cicloplegia nas medições oculares. Métodos: participaram do estudo 33 voluntários saudáveis (média de idade [± DP], 32,97 anos [± 5,21 anos]). Foram medidos o comprimento axial, a espessura macular e coroidal e o erro refrativo, bem como realizados exames de imagem da topografia corneana e do segmento anterior. Em seguida, foi induzida a acomodação farmacológica aplicando-se colírio de pilocarpina (cloridrato de pilocarpina a 2%) e as medições foram repetidas nos participantes. As mesmas medições foram repetidas depois de induzir a cicloplegia completa com colírio de ciclopentolato (cloridrato de ciclopentolato a 1%) e foram avaliadas as correlações entre as medidas. Resultados: Identificou-se aumento significativo da espessura coroidal subfoveal com o uso da pilocarpina a 2% (sem colírio, 319,36 ± 90,08 µm; com a instilação de pilocarpina, 341,60 ± 99,19 µm; com a instilação de ciclopentolato, 318,36 ± 103,0 µm; p<0,001). Detectou-se também aumento significativo do comprimento axial (sem colírio, 23,26 ± 0,83 mm; com a instilação de pilocarpina, 23,29 ± 0,84 mm; com a instilação de ciclopentolato, 23,27 ± 0,84 mm; p=0,003). Ao se comparar a acomodação farmacológica e a cicloplegia, houve diferença significativa na espessura macular central (com a instilação de pilocarpina, 262,27 ± 19,34 µm; com a instilação de ciclopentolato, 265,93 ± 17,91 µm; p=0,016). Observou-se que a miose associada à pilocarpina (p<0,001) e o desvio miópico (p<0,001) foram mais severos nos olhos azuis que nos castanhos. Conclusão: A acomodação farmacológica pode alterar medidas oculares como a espessura da coroide e o comprimento axial. Essa possibilidade deve ser levada em consideração ao se efetuarem medições oculares, tais como cálculos de potência de lentes intraoculares.(AU)

Is hypermetropia regressing in accommodative esotropia? / A hipermetropia regride na esotropia acomodativa?

ABSTRACT Purposes: To evaluate the relationship of changes in hypermetropia and ocular alignment in patients with accommodative esotropia. Methods: The medical records of consecutive patients diagnosed with refractive accommodative esotropia (esotropia eliminated or decreased to within 10 D with full hyperopic correction) were retrospectively reviewed. Cycloplegic refractions culled from medical records were converted into spherical equivalents. Presence of amblyopia, changes in refractive error and ocular alignment at admission and after the follow-up period were evaluated. Results: Seventy patients (mean age: 6.01 ± 5.41 years; female: 60.6%; mean follow-up: 5.8 ± 3 years) had corrected esotropia of 40 ± 20 prismatic diopters at admission. The average decrease per year in near and distance deviations with glasses was 1.71 ± 3.96 prismatic diopters/year and 1.09 ± 3.25 prismatic diopters/year, respectively. The total myopic shift of the right and left eyes was 1.08 ± 1.35 D and 1.20 ± 1.40 D, respectively. Myopic shift/year was 0.22 D/year and 0.26 D/year, respectively. The correlation between the rate of myopic shift and rate of change in corrected near deviation was weak. The correlation for the rate of myopic shift was not high for the right and left eyes (r=0.18; p=0.15). Conclusion: The amount of deviation and hypermetropia gradually decreased in accommodative esotropia during follow-up. On the other hand, it may be incorrect to assure patients that the amount of deviation will decrease in parallel with the refractive error.(AU)

RESUMO Objetivo: Avaliar a relação entre alterações na hipermetropia e o alinhamento ocular em pacientes com esotropia acomodativa. Métodos: Foram analisados retrospectivamente prontuários médicos de pacientes consecutivos diagnosticados com esotropia acomodativa refrativa (com esotropia eliminada ou reduzida a menos de 10 D com correção completa da hipermetropia). As medidas de refração em cicloplegia obtidas dos prontuários foram convertidas em equivalentes esféricos. Avaliaram-se ainda a presença de ambliopia, alterações do erro refrativo e o alinhamento ocular à admissão e depois do período de acompanhamento. Resultados: Setenta pacientes (média de idade=6,01 ± 5,41 anos, 60,6% do sexo feminino, acompanhamento médio de 5,8 ± 3 anos) apresentaram esotropia de 40 ± 20 dioptrias prismáticas (DP) para perto à admissão. A diminuição média anual no desvio para perto e para longe com o uso de óculos foi de 1,71 ± 3,96 DP/ano e 1,09 ± 3,25 DP/ano, respectivamente. Os desvios miópicos totais dos olhos direito e esquerdo foram de 1,08 ± 1,35 D e 1,20 ± 1,40 D, respectivamente. Os desvios miópicos anuais foram de 0,22 D/ano e 0,26 D/ano para os olhos direito e esquerdo, respectivamente. A correlação entre a taxa de desvio miópico e a taxa de alteração do desvio para perto corrigido foi fraca. A correlação da taxa de desvio miópico não foi alta para os olhos direito e esquerdo (r=0,18, p=0,15). Conclusão: A quantidade de desvio e a hipermetropia diminuem gradualmente na esotropia acomodativa durante o acompanhamento. Por outro lado, pode não ser apropriado garantir aos pacientes que o desvio diminuirá em paralelo ao erro refrativo.(AU)

The Effect of Smartphone Usage on Accommodation Status

@#Introduction: Usage of smartphones have increased rapidly because of its importance in our daily life. This led to an increase in incidence of ocular problems among smartphone users. This research was conducted to determine the effect of smartphone usage on accommodation status. Methods: A cross-sectional study was conducted among young adults aged 19 to 30 years old in Management and Science University, Shah Alam. All subjects were asked to use smartphone for 20 minutes. The symptoms and accommodation status were evaluated before and after the smartphone usage. Results: Total subjects showed the mean age of 23.60 ± 2.77 years, 50% (n = 20) were males and 50% (n = 20) were females. The mean smartphone usage per day was 8.60 ± 2.80) hours. After 20 minutes of smartphone usage, subjects complained of tired eyes (92.50%), dry eyes (90.00%), blurred vision (87.50%), and headache (82.50%). Paired t-test showed significant reduction in amplitude of accommodation, monocularly from 9.9 ± 1.9 D to 8.76 ± 2.50 D (p = 0.00), and binocularly from 12.01 ± 1.95 D to 10.96 ± 2.16 D (p = 0.00); monocular accommodative facility from 13.93 ± 3.13 cpm to 11.10 ± 4.32 cpm (p = 0.00) and binocular accommodative facility from 12.70 ± 3.57 cpm to 9.70 ± 4.21 cpm (p = 0.00); positive relative accommodation from -2.72 ± 0.87 D to -2.13 ± 1.28 D (p = 0.00) and increase in lag of accommodation from 0.4 ± 0.26 D to 0.93 ± 0.48 D (p = 0.00). Conclusion: This study shows that there were significance changes on accommodation status after 20 minutes of smartphone usage which can lead to weakness of accommodation.

Multisectorial changes in the ciliary muscle during accommodation measured with high-resolution optical coherence tomography / Alterações multissetoriais no músculo ciliar durante a acomodação com uma tomografía de coerência óptica de alta resolução

ABSTRACT Purpose: To measure changes in the anterior ciliary muscle during accommodation at the nasal, superior, temporal, and inferior sectors by means of an anterior chamber optical coherence tomographer, and correlate them with vergence changes. Methods: Twenty-four subjects with healthy, phakic eyes, whose mean age was 27.1 ± 8.9 years, underwent measurement with an anterior chamber optical coherence tomographer. The anterior ciliary muscle was measured at the nasal, temporal, superior, and inferior sectors for 0, -1, -2, and -3 D of vergence. A linear model was used to assess the correlation of each eye parameter with the accommodative demand. Results: The anterior ciliary muscle area significantly increased with accommodation for each sector, with a maximum increase of about 30% for the nasal-temporal sectors and about 25% for the inferior-temporal sectors. The linear model showed a tendency toward a positive relationship between change in the ciliary muscle area of each sector and vergence. Conclusion: The anterior ciliary muscle area tends to increase with accommodation, although the increase has been shown to be symmetric between the pair sectors superior-nasal and inferior-temporal. These results may help to increase understanding of accommodation biometry and biomechanics.

RESUMO Objetivo: Medir as alterações do músculo ciliar anterior durante a acomodação nos setores nasal, superior, temporal e inferior, através de um tomógrafo de coerência óptica de câmara anterior, e correlacioná-las com alterações de vergência. Métodos: Vinte e quatro indivíduos com olhos saudáveis e fácicos, com idade média de 27,1 ± 8,9 anos, foram submetidos à medida com um tomógrafo de coerência óptica de câmara anterior. O músculo ciliar anterior foi medido nos setores nasal, temporal, superior e inferior para 0, -1, -2 e -3D de vergência. Um modelo linear foi utilizado para avaliar a correlação de cada parâmetro do olho com a demanda acomodativa. Resultados: A área do músculo ciliar anterior aumentou significativamente com a acomodação em cada setor, com um aumento máximo foi de cerca de 30% para os setores naso-temporais, e cerca de 25% para os inferiores-temporais. O modelo linear mostrou uma tendência para uma relação positiva entre a alteração da área do músculo ciliar de cada setor e a vergência. Conclusão: A área do músculo ciliar anterior tende a aumentar com a acomodação, embora o aumento tenha se mostrado simétrico entre os setores superior-nasal e inferior-temporal. Estes resultados podem ajudar a aumentar a compreensão da biometria e biomecânica da acomodação.

Assessing the accommodation response after near visual tasks using different handheld electronic devices / Avaliação da resposta de acomodação após tarefas visuais próximas usando diferentes dispositivos eletrônicos portáteis

ABSTRACT Purpose: To assess the accommodation response after short reading periods using a tablet and a smartphone as well as determine potential differences in the accommodation response at various stimulus vergences using a Hartmann- Shack aberrometer. Methods: Eighteen healthy subjects with astigmatism of less than 1 D, corrected visual acuity of 20/20 or better, and normal findings in an ophthalmic examination were enrolled. Accommodation responses were obtained under three different conditions: accommodation system of the eye relaxed and visually stressed with a tablet and an smartphone for 10 min, at a distance of 0.25 m from the subject's eyes. Three measurements of accommodation response were monocularly acquired at stimulus vergences ranging from 0 to 4 D (1-D step). Results: No statistically significant differences were found in the accommodation responses among the conditions. A moderate but gradually increasing root mean square, coma-like aberration was found for every condition. Conversely, the spherical aberration decreased as stimulus vergences increased. These outcomes were identified in comparison to the one-to-one ideal accommodation response, implying that a certain lag value was present in all stimulus vergences different from 0 D. Conclusions: The results support the hypothesis that the difference between the ideal and real accommodation responses is mainly attributed to parameters associated with the accommodation process, such as the near visual acuity, depth of focus, pupil diameter, and wavefront aberrations. The wavefront aberrations were dependent on the 3-mm pupil size selected in this study. The accommoda tion response was not dependent on the electronic device employed in each condition, and it was mainly associated with young age and level of amplitude of accommodation of the subjects.

RESUMO Objetivo: Avaliar a resposta de acomodação após períodos de leitura curtos usando um tablet e um smartphone, bem como para determinar potenciais diferenças na resposta de acomodação em estímulos de várias vergências com uma aberrômetro Hartmann-Shack. Método: Dezoito indivíduos saudáveis com astigmatismo inferior a 1 D, apresentando acuidade visual corrigida de 20/20 ou melhor com exame oftalmológico normal foram avaliados. As respostas acomodativas foram obtidas em três condições diferentes: sistema de acomodação com o olho relaxado, e visualmente estressado com um tablet e um smartphone por 10 min, a uma distância de 0,25 m dos olhos dos sujeitos. Três medidas de resposta acomodativa foram obtidas monocularmente com estímulos cujas vergências variaram de 0 a 4 D (intervalos de 1 D). Resultados: Não houve diferença estatisticamente significativa entre as respostas acomodativas em todas as condições. Foi observada moderada aberração do tipo coma com aumento progressivo para cada condição, enquanto houve diminuição da aberração esférica com o aumento das vergências do estímulo. Estes resultados foram identificados em comparação com a resposta acomodativa de um-para-um ideal, o que implica que um certo valor de desfasagem estava presente em todos os estímulos com vergências diferentes de 0 D. Conclusões: Os resultados apoiam a hipótese de que a diferença entre as respostas acomodativas ideal e real é atribuída principalmente a parâmetros tais como a acuidade visual para perto, profundidade de foco, diâmetro pupilar e aberrações de frente de onda, associados ao processo acomodativo. As aberrações de frente de onda foram dependentes do tamanho da pupila de 3 mm, selecionado neste estudo. A resposta acomodativa não foi dependente do dispositivo eletrônico empregue em cada condição e foi associada principalmente à idade jovem e ao nível da amplitude de acomodação dos sujeitos avaliados.

Refração e síndrome de fadiga visual no uso de sistema de televisão ULTRA- HD-3D- 4K de tela curva / Refraction and visual fatigue syndrome on watching the ULTRA HD 4k television curved screen system

RESUMO Objetivo: Avaliar uma possível desordem de sensibilidade ocular (similar a glare), com sintomas de fadiga visual, através da observação de tela de televisão ULTRA HD- 3D- 4K de tela curva de 55 polegadas, em voluntários com exame oftalmológico normal. Métodos: Um estudo prospectivo, longitudinal, caso-controle, com formação de grupos por faixa etária e com critérios de inclusão e exclusão. Uma comparação de um vídeo documentário gravado com resolução HD 4K e o mesmo documentário gravado em FULL HD antes e após a tele-audiência anterior consistindo numa avaliação de três fases do estudo com os mesmos critérios. A fadiga visual foi analisada por meio de um questionário padronizado de queixas de síndrome de fadiga visual comuns e comparado a teste de sensibilidade ao contraste, teste de amplitude de acomodação e convergência, teste de frequência de piscar e teste de movimentos sacádicos conjugados oculares de grande amplitude. Equipamentos acessórios como tablets com câmara digitais serão utilizados para gravação de vídeos da frequência de piscar, e de movimentos oculares sacádicos durante toda a audiência televisiva. Analise estatística com Teste de Qui quadrado, teste t de Student, teste de Tukey e teste F com analise de Variância foram feitos para dados em tabelas de contingência e gráficos caixa em Box Plot. Nível de significância estimado em 5%. Resultados: Oitenta voluntários normais foram avaliados e avaliados como inferência de expressividade estatística alpha (α) de 10%, sem obter significância de 5% para as queixas de um questionário de Síndrome de Fadiga Visual. Outros testes estatísticos revelam dados de significância de 5% numa inferência global da pesquisa quanto à frequência de piscar e de movimentos sacádicos conjugados oculares de grande amplitude. Conclusão: Telas de televisão de alta resolução ULTRA HD 4K, podem provocar queixas de fadiga visual numa população de características pouco comuns (com baixa frequência de piscar palpebral e movimentos sacádicos conjugados), mas existentes. O baixo índice de estatística significativa poderá revelar-se de maior expressão no uso de uma amostragem de pesquisa mais numerosa. Os autores chamam a atenção para a possibilidade de incremento desse efeito de fadiga visual no futuro advento de Sistema de Televisão ULTRA HD 8K.

ABSTRACT Purpose: To evaluate eye sensitivity disorder (similar to glare), with symptoms of visual fatigue, through watching television ULTRA HD3D-55-inch 4K curved screen among volunteers with normal eye examination. Methods: A prospective, longitudinal, case-control study, with inclusion and exclusion criteria and groups formation enrolled by age range. A comparison of a video documentary presented with the ULTRA HD TV 4K and with the FULL HD TV before and after the previous tele-audience, consisting of an evaluation of three phases of the study regarding the case-control criteria. The main variable analyzed was a questionnaire of visual fatigue syndrome complaints which was compared with secondary variables as the contrast sensitivity test, amplitude of accommodation test, blink frequency test, and test of conjugated saccadic eye movements of big amplitude. Tablets with digital camera equipment were used for video recording of the blink frequency, and saccadic eye movements throughout the television audience. Statistical analysis with Chi Square test. Results: Eighty healthy volunteers were evaluated and assessed as expressiveness of statistical inference alpha (α) of 10%, without obtaining significance of 5% for complaints of a questionnaire Visual Fatigue Syndrome. Other statistical tests showed 5% of significance of data in a global inference research on the frequency of blinking and combined saccadic movements of great amplitude. Conclusion: High resolution television screens ULTRA HD 4K may cause complaints of eyestrain in a population with some uncommon characteristics (low eyelid blink frequency and conjugated saccades movements). The low statistical significant index could be increased in a research with a higher number of participants. The authors call attention to the possibility of increasing this visual fatigue effect in the future advent of Television System ULTRA HD 8K.

Association of fusional convergence and divergence with control ability in children with intermittent exotropia / 中华实验眼科杂志

Background Intermittent exotropia is a type of strabismus that between latent extropia and manifest extropia.The assessment of fusional convergence/divergence is important for understanding control ability of exodeviation in children with intermittent exotropia.Objective This study was to analyze the correlations between fusional convergence/divergence and control ability of exodeviation in children with intermittent exotropia.Methods Sixty-three children with intermittent exotropia were recruited in Beijing Tongren Eye Centre from July 2013 to February 2014 under the informed consent of children and their parents.Angle of deviation was measured by wearing prism and covering method alternately.The control ability of exodeviation was evaluated and scored by the Revised Newcastle Control Score (RNCS),and fusional convergence and divergence were measured with 1 Δ-40Δ horizonal prisms and regulating targets.The correlations between the measured parameters of fusional convergence/divergence and control scores of exotropia were analyzed by Spearman rank correlation analysis.Results The mean diopter of the right and left eyes was (-1.95 ± 1.63)D and (-2.01 ± 1.73)D,respectively,and the mean deviation angle for distantly and near was (36.67 ± 15.69) Δ and (38.25 ± 14.83) Δ,respectively,without significant differences between them (diopter:t =-0.13,P＞0.05;deviation angle:t =-0.57,P＞0.05).Considerably negative correlations were found between the breakpoints of fusional convergence for distant or near and control scores of exodeviation (rs =-0.41,P=0.03;rs =-0.56,P＜0.01).No significant correlations were found between the breakpoints of fusional divergence for distantly or near and control scores of exodeviation (rs =0.05,P =0.78;rs =0.04,P ＜0.75).In addtion,there was no significant correlation between fusional recovery level and control scores (both at P ＞ 0.05).Conclusions Breakpoints of fusional convergence may be useful in grading the severity of intermittent exotropia in children,and it is probably one of the surgical indications of intermittent exotropia.

Influences of short-term iPAD game on accommodative response and microfluctuation in adolescent myopia patients / 中华实验眼科杂志

Background Using tablet computer at a short distance is one of the risk factors resulting to pathogenesis and progression of myopia.Studying the effect of such device on accommodative system of human eyes can provide further insights into myopia control.Objective This study was to explore the influences of playing iPAD game for a short duration on accommodative response,accommodative microfluctuation and pupil diameter in adolescent myopia patients.Methods Sixty adolescent myopic patients were included in Peking University People 's Hospital from August 2014 to April 2015,with the mean age (11.6±2.6) years and mean spherical equivalent refraction (SER) (-2.38±1.08)D.The patients were randomly divided into 3 groups according to different playing duration of iPAD game,including 3-minute group,5-minute group and 10-minute group.An open-field infrared refractometer was used to record pupil diameter and accommodation-associated data before and after playing iPAD game.Accommodative response was defined as the difference between the recorded value and theoretical accommodative response,and root mean square (RMS) was used to describe the amplitude of accommodative microfluctuation.One-dimension discrete Fourier transformation was used to analyze spectral characteristic of accommodative response curve.Paired t tests were used to compare these accommodative parameters before and after playing game,while Wilcoxon signed-rank tests were applied for analyzing high frequency component of accommodative microfluctuation.This research conforms to the declaration of Helsinki,and was approved by Peking University People's Hospital Ethics Committee,all the subjects and their guardian signed informed consent.Results The accommodative response values before and after playing iPAD game in 10-minute group were (0.81 ±0.29)D and (0.74 ± 0.27) D,respectively,with significant difference between them (t =2.263,P =0.036),and no significant differences were found in the accommodative response values before and after playing iPAD game in the 3-minute group and 5-minute group (both at P＞0.05).The RMS after playing iPAD game was (0.31 ±0.08) D in the 10-minute group,which was significantly higher than (0.27 ± 0.09) D before playing iPAD game (t =-2.259,P =0.036).The high-frequency spectral power of accommodative response curves in all the three groups were increased after playing iPAD game in comparison with before playing iPAD game,with significant differences in the 5-minute group and 10-minute group (Z =-2.213,-2.016;both at P ＜ 0.05),and the pupil diameters were significantly decreased after playing iPAD game in comparison with before playing iPAD game,with significant differences in the 5-minute group and 10-minute group (t =2.428,P =0.026;t =2.515,P =0.021).Conclusions Short-term exposure to iPAD does not deteriorate accommodative lag in adolescent myopic patients.However,the increase of amplitude and high-frequency spectral power of accommodative microfluctuation,together with accommodation lag will result in blurred images and may bring adverse effects on myopic eyes.

Correlation between the use of the accommodation and symptoms of asthenopia in hyperopic patients

Purpose: The objective of this paper was to compare the symptoms of asthenopia in patients at different levels of hyperopia and corrected for different accommodative efforts. Methods: This study is an experimental design and quantitative approach. Sixty-nine hyperopic patients aged between 15 and 40 were selected. Individuals with a diagnosis of accommodative insufficiency and paralysis, accommodative spasm or any type of ocular deviation were excluded. Subjects were randomly divided into four groups. Each one performed a nearvision task with different corrective lenses, varying the value of the accommodative effort. Results: There is significant reduction in the asthenopia score during the near-vision task when leaving 35% or more of the amplitude of accommodation in reserve. The linear regression showed that the variables total hyperopia (r = 0.109) and the difference between static and dynamic refraction (r = 0.135) did not obtain significant linear relationship to the asthenopia score. Conclusions: There is significant reduction in the asthenopia score when leaving 35% or more of the amplitude of accommodation in reserve. The symptoms of asthenopia are not associated to the severity of the hyperopic refractive error. The search for symptoms before the near vision task, using a questionnaire, related to the symptoms during the accommodative effort task, revealing the importance of searching for complaints about asthenopia during anamnesis, which can help ophthalmologists with prescriptions of glasses for hyperopic patients with asthenopia.

Objetivos: O presente estudo objetivou avaliar os efeitos do esforço acomodativo e do poder do erro refrativo nos sintomas de astenopia. Métodos: Trata-se de um modelo de estudo experimental e abordagem quantitativa, cuja amostra consistiu de 69 pacientes hipermetropes entre 15 e 40 anos de idade. Foram excluídos os indivíduos com diagnóstico de insuficiência ou paralisia da acomodação, espasmo de acomodação ou qualquer tipo de desvio ocular. Os pacientes foram alocados aleatoriamente em quatro grupos. Cada grupo realizou o trabalho de visão para perto com correções diferentes, variando o valor do esforço acomodativo. Resultado: Houve melhora significativa dos sintomas de astenopia com correções que proporcionaram mais de 35% da amplitude de acomodação em reserva. Não houve relação estatisticamente significativa entre os sintomas e o valor do erro refrativo. Conclusão: Há uma redução significativa dos sintomas quando os pacientes mantêm 35 % ou mais de sua acomodação em reserva. Os sintomas de astenopia não estão associados à gravidade do defeito hipermetrópico. A pesquisa de sintomas antes do teste, através de um questionário, foi o fator que melhor se relacionou com os sintomas durante o teste de visão para perto, revelando a importância da pesquisa das queixas de astenopia durante anamnese na prescrição de lentes para visão de perto.

Association analysis of accommodative microfluctuations and wavefront aberration in emmetropia and myopia in teenagers / 中华实验眼科杂志

Background When focusing on a target,the accommodative system exhibits small variations in power within a range,termed microfluctuations.Exploring the correlation between the characters of microfluctuations and the aberrations of the eyes through a critical period-teenager can deepen the understanding of the onset and development of myopia.Objective This study was to investigate the correlation between accommodative microfluctuations and wavefront aberrations of human eyes,and to explore the role of accommodative microfiuctuations in the development of myopia.Methods A cross-sectional study was designed and performed.Fifty-four teenagers aged from 12 to 15 years were enrolled in this study in Eye Hospital,Wenzhou Medical University from 2010 to 2011,including 19 emmetropic subjects,18 incipient myopic subjects and 17 progressive myopic subjects,who were chosen based on the refractive changes for the last two years.The accommodative response and microfluctuations were measured by WAM-5500 infrared autorefractor with RSVP at 25,33 and 50 cm respectively,each RSVP distance was tested for 5 minutes.The accommodative values were divided into low frequency component (LFC) (0-0.6 Hz),middle frequency component(MFC) (0.6-0.9 Hz) and high frequency component (HFC) (1.0-1.4 Hz) after Fourier spectrum analysis.The wavefront aberrations of the whole eye and corneal were recorded by i-Trace aberrometer and Humphrey corneal topography.The differences of accommodative response,microfluctuations and aberrations were evaluated and compared among the emmetropic group,incipient myopic group and progressive myopic group.The correlations of accommodation and aberrations were analyzed.This study followed Declaration of Helsinki,and informed consent was obtained from each subject.Results Under the 25 cm and 33 cm reading distance,the accommodative response values were (2.78 ± 0.35) D and (2.19 ± 0.27) D in the emmetropic group,which were significantly higher than (2.44±0.33) D and (1.89±0.35)D in the progressive myopic group (P=0.002,0.003).LFC,MFC and HFC were remarkably increased as the reading distance decreased (Fdistance =8.480,14.270,21.400;all at P ＜0.01).A significant difference was seen in LFC among different reading distances (Fgroup =4.115,P＜0.05),and the LFCs in the progressive myopic group were considerably higher than those in the emmetropic group in the 25,33 and 50 cm reading distances (P=0.044,0.038,0.032).No significant differences were found in MFC and HFC among the three groups (Fgroup =0.859,0.682;both at P＞0.05).Under the 25 cm and 33 cm reading distances,significant positive correlations were found between LFC and corneal coma,intraocular coma,whole ocular aberrations or intraocular higher order aberrations (all at P＜0.05),however,no significant correlations were seen between MFC or HFC and wavefront aberrations (all at P＞0.05).Conclusions In teenagers,the accommodative response of emmetropia is much stronger than that of progressive myopia,and the accommodative microfluctuation in emmetropia and incipient myopia is much less than that in progressive myopia.These shifts are possibly associated with the variability,and microfluctuations of accommodation is greater in progressive myopes than emmetropes.There are certain correlations between wavefront aberrations and accommodative microfluctuations.The refractive group differences in the accommodative microfluctuations may be related to differences in the wavefront between myopes and emmetropes.Under near reading distance,LFC is correlated with higher order aberrations.

Effect of monocular depth perception on accommodative response / 中华实验眼科杂志

Background Different depthes or distances are prompted with many visual cues on the flat screen.Which kind of depth cues plays a major role in the accommodation of human eyes,in addition,whether this effect exists in the different distance are still below understood.Objective This study was to research the effect of the monocular space depth perception on accommodative response at different distances,and to analyze the effect of linear perspective and size-constancy perceptual depth cues on the level and amplitude of accommodative fluctation.Methods Four groups of visual targets were designed by FLASH software and placed at the front of eyes with the distance of 50 cm or 33.3 cm,representing static change from far to near and dynamic change from far to near,from near to far respectively.Twenty-six healthy volunteers aged 22-26 years were included in this study,with the spherical power of (-4.06± 1.99) D and cylindrical power of (-0.38±0.41) D under the informed consent.The accommodative response and accommodative fluctuations during monocularly watching the targets were recorded at 5 times/second by Grand Seiko WAM 5500 automatic infrared refractor.This study was approved by Ethic Committee of Wenzhou Medical University,and written informed consent was obtained from each subject before entering the study group.Results At the distance of 50 cm,the accommodative response caused by the depth perception of near was (1.52±0.46) D,the one of distance was (1.37±0.46) D,with a significant difference of 0.15 D under the combined effect of linear perspective and size-constancy (P =0.016).The accommodative response caused by the depth perception of big car was (1.43 ± 0.35) D,and the one of small car was (1.43 ± 0.36) D,without statistically significant difference under the effect of size-constancy alone (P =0.467).At the distance of 33.3 cm,the accommodative response caused by the depth perception of near was (2.40±0.53)D,and the one of distance was (2.35 ±0.51) D,without significant difference under the combined effect of linear perspective and size-constancy (P=0.379).The accommodative response caused by the depth perception of big car was (2.38±0.48)D,the one of small car was (2.39±0.52)D,without statistically significant difference under the effect of size-constancy alone (P =0.820).In addition,the total curve of accommodative microfluctuation showed apparent fluctuation periodically caused by the distance perception involving linear perspective only.Conclusions Monocular space depth perception has some impacts on the accommodative response at certain distance.Linear perspective,which is one of the depth cues of space perception,plays a major role in the accommodative response.Compared with the size-constancy,linear perspective can provide depth perception at higher level.The size-constancy has a little or contrast impact to the accommodation,because it depends on the assistance from other depth cues like linear perspective.

Influences of prisms on accommodative response and microfluctuation in emmetropias / 中华实验眼科杂志

Background How to control progression of myopia is a central issue in clinical optometry.Some clinical trials showed that wearing base-in (BI) prism can slow down progression of myopia to certain degree.However,whether BI prism or base-out (BO) prism should be used is worth discussing.Objective This study was to investigate the influences of different prisms on accommodative response and microfluctuation in emmetropias.Methods This clinical trail was approved by Ethic Committee of Peking University People's Hospital.During July in 2014,twenty-two emmetropias of 22 normal volunteers aged 21-27 years were recruited from Peking University People's Hospital under the written informed consent.An open-field infrared refractometer was used to monitor and record pupil diameter and accommodative response under three conditions including non-prism,3△ BI prism,and 3△ BO prism.The accommodative response value was calculated as the difference between reading value and-3.0 D,and root mean square (RMS) of accommodative response value served as amplitude of accommodative microfluctuation.Spectrum of accommodative response was analyzed by one dimension discrete Fourier transformation.The differences of accommodative response value,amplitude of accommodative microfluctuation and pupil diameter among three conditions were compared using repeated one-way ANOVA.Results The accommodative response values were (+0.31±0.78),(+0.51±0.75) and (+0.18±0.72) D under the non-prism,3△BI prism and 3△BO prismconditions,respectively,with a significant difference among them (F =28.078,P =0.000),and compared with the non-prism condition,the accommodative lag of 3△BI prism condition was increased and that of 3△BO prism condition was reduced (P =0.000,0.012).No significant difference was found in the amplitude of accommodative microfluctuation among the three conditions (F=0.062,P =0.879).The percentages of low frequency signal power (0-0.5 Hz)/total power (0-2.5 Hz) was 97.5％,98.3％ and 91.4％ under the non-prism,3△BI prism and 3△BO prism condition,respectively.The pupil diameter was (5.37-±0.69) mm under the 3 △ BI prism condition,which was larger than (5.07±0.66) mm under the non-prism condition and (5.01 ±0.69) mm under the 3△ BO prism condition (both at P =0.000).Conclusions Compared with wearing 3△ BI prism,wearing 3△ BO prism lessens the accommodative lag,decreases the pupil diameter and reduces the power of low frequency component in accommodative response.

Changes in anterior chamber eye during accommodation as assessed using a Dual Scheimpflug system / Mudanças na câmara anterior do olho durante a acomodação avaliadas por meio de sistema de Scheimpflug duplo

Purpose: To study the changes in anterior chamber depth (ACD), anterior chamber angle (ACA), and pupil diameter (PD) during accommodation. Methods: Eighty eyes of 80 subjects, aged 22 to 40 years, were included. The rotating Dual Scheimpflug and a Placido disc system (Galilei G4, Ziemer Ophthalmic Systems AG, Switzerland) was used to measure the changes in ACD, ACA, and PD during accommodation. ACD measurement was taken for the central zone and for 4 more positions, each in different orientation (nasal, superior, temporal and inferior), 4 mm away from the centre. ACA was measured for the whole eye as well for the nasal, superior, temporal, and inferior quadrants. These metrics were obtained for various accommodation stimuli, ranging from +1 D to -4 D in 1-D steps. Results: For a given position, the ACD did not vary significantly with accommodation. For the central ACD, the percentage of relative change between far and near vision was -4.11%. The ACA was significantly lower at the inferior, temporal, and superior positions. There was no change in the ACA of the whole eye and that of the nasal orientation. These two eye metrics were significantly lower in the superior-nasal than in the inferior-temporal region. At each vergence studied, the PD decreased significantly with accommodation. The relative change after the -4 D stimulus was -8.13%. Conclusion: ACA and PD varied significantly with accommodation, whereas no such variation of ACD was observed. Further, the anterior chamber was found to be asymmetrical, with the nasal-superior area becoming significantly shallower than the inferior temporal region. .

Objetivo: Estudar as mudanças na profundidade da câmara anterior (ACD), ângulo da câmara anterior (ACA) e diâmetro da pupila (PD) durante a acomodação. Métodos: Foram incluídos 80 olhos de 80 indivíduos com idades entre 22 e 40 anos. Um sistema rotacional de Scheimpflug duplo acoplado a um sistema de disco de Placido (Galilei G4, Ziemer Ophthalmic Systems AG, Suíça) foi usado para medir as mudanças na ACD, ACA e PD, durante a acomodação. As medidas da ACD foram consideradas na zona central e em mais 4 posições, cada uma em orientação diferente (nasal, superior, temporal e inferior), a 4 milímetros de distância do centro. O ACA do olho inteiro, assim como nos quadrantes nasal, superior, temporal e inferior foram medidos. Todos estes indicadores foram obtidos por vários estímulos acomodativos, que variaram de +1 D a -4 D em intervalos de 1 D. Resultados: A ACD não variou significativamente com acomodação para qualquer determinada orientação, sendo a percentagem de variação relativa entre longe e visão de perto -4,11% para a ACD central (onde sinal negativo representa uma diminuição na ACD). Em relação ao ACA, este diminuiu significativamente em posições inferiores, temporais e superiores. O ACA total de olho e o ACA nasal não se alterou. Estas duas métricas oculares foram significativamente menores no par nasal-superior do que no temporal-inferior. Finalmente, PD diminuiu significativamente com a acomodação em cada vergência estudada, a mudança relativa após o estímulo de -4 D foi -8,13%. Conclusão: ACA e PD variaram significativamente com a acomodação, enquanto ACD não. Além disso, a câmara anterior se mostrou alterar assimetricamente, com a área nasal-superior se tornando ...

An evaluation of estimation methods for determining addition in presbyopes / Avaliação de diferentes métodos para determinar adição em présbitas

PURPOSE: The optical correction of presbyopia must be handled individually. Our aim was to compare the methods used in addition to the refractive near vision, with the final addition used in presbyopic patients. METHODS: Eighty healthy subjects with a mean age of 49.7 years (range 40 to 60 years) were studied. Tentative near additions were determined using four different techniques: one-half amplitude accommodation with minus lenses (AAL); one-third accommodative demand with positive lens (ADL); balanced range of accommodation with minus and positive lenses (BRA) and crossed cylinder test with initial myopisation (CCT). The power of the addition was then refined to arrive at the final addition. RESULTS: The mean tentative near additions were lower than the final addition for ADL and BRA addition methods. The mean differences between tentative and final additions were low for all the tests examined (less than 0.25 D). The intervals between the 95% limits of agreement differed substantially and were always higher than ±0.50 D. CONCLUSION: All the methods used displayed similar behavior and provided a tentative addition close to the final addition. The coefficient of agreements (COA) detected suggests that every tentative addition should be adjusted according to the particular needs of the patient.

OBJETIVO: A correção óptica da presbiopia deve ser manejada individualmente. Nosso intuito é de comparar os métodos usados para calcular a adição na elaboração do grau para perto em pacientes présbitas. MÉTODOS: Oitenta pacientes com média de idade de 49,7 anos (intervalo de 40 a 60 anos) foram estudados. Adições provisórias foram determinadas usando quatro diferentes técnicas: metade da amplitude de acomodação com lentes negativas (AAL); um terço da demanda acomodativa com lentes positivas (ADL); média aritmética da acomodação usando lentes positivas e negativas (BRA); teste com o cilindro cruzado com miopização (CCT). O grau final foi refinado até chegar a graduação final da adição. RESULTADOS: A média das adições nos testes foram menores que as adições finais nos métodos ADL e BRA. As diferenças médias entre os testes e o grau final foram baixas em todos os métodos (menores que +0,25 D). Os intervalos entre os 95% dos limites da concordância diferenciaram substancialmente e foram todos maiores que ±0.50 D. CONCLUSÃO: Todos os métodos usados demonstraram comportamentos similares e forneceram resultados bem próximos da adição final. O coeficiente de concordância (COA) detectado, sugere que todos os métodos utilizados devem ser ajustados de acordo com as necessidades do paciente.

Comparison of wavefront aberrations under cycloplegic, scotopic and photopic conditions using WaveScan / Comparação de aberrações de frente de onda sob cicloplegia, condições escotópica e fotópica usando WaveScan

PURPOSE: To evaluate the differences of wavefront aberrations under cycloplegic, scotopic and photopic conditions. METHODS: A total of 174 eyes of 105 patients were measured using the wavefront sensor (WaveScan® 3.62) under different pupil conditions: cycloplegic 8.58 ± 0.54 mm (6.4 mm - 9.5 mm), scotopic 7.53 ± 0.69 mm (5.7 mm - 9.1 mm) and photopic 6.08 ± 1.14 mm (4.1 mm - 8.8 mm). The pupil diameter, standard Zernike coefficients, root mean square of higher-order aberrations and dominant aberrations were compared between cycloplegic and scotopic conditions, and between scotopic and photopic conditions. RESULTS: The pupil diameter was 7.53 ± 0.69 mm under the scotopic condition, which reached the requirement of about 6.5 mm optical zone design in the wavefront-guided surgery and prevented measurement error due to the pupil centroid shift caused by mydriatics. Pharmacological pupil dilation induced increase of standard Zernike coefficients Z3-3, Z4(0) and Z5-5. The higher-order aberrations, third-order aberration, fourth-order aberration, fifth-order aberration, sixth-order aberration, and spherical aberration increased statistically significantly, compared to the scotopic condition (P<0.010). When the scotopic condition shifted to the photopic condition, the standard Zernike coefficients Z4(0), Z4², Z6-4, Z6-2, Z6² decreased and all the higher-order aberrations decreased statistically significantly (P<0.010), demonstrating that accommodative miosis can significantly improve vision under the photopic condition. Under the three conditions, the vertical coma aberration appears the most frequently within the dominant aberrations without significant effect by pupil size variance, and the proportion of spherical aberrations decreased with the decrease of the pupil size. CONCLUSIONS: The wavefront aberrations are significantly different under cycloplegic, scotopic and photopic conditions. Using the wavefront sensor (VISX WaveScan) to measure scotopic wavefront aberrations is feasible for the wavefront-guided refractive surgery.

OBJETIVO: Avaliar as diferenças de aberrações de frente de onda, em diferentes condições pupilares: sob cicloplegia, escotópica e fotópica. MÉTODOS: Um total de 174 olhos de 105 pacientes foram avaliados utilizando o sensor de frente de onda (WaveScan® 3.62) em diferentes condições pupilares: sob cicloplegia 8,58 ± 0,54 mm (6.4 mm-9.5 mm), escotópica 7,53 ± 0,69 mm (5,7 mm - 9,1 mm) e fotópica 6,08 ± 1,14 mm (4,1 mm - 8,8 mm). Diâmetro da pupila, coeficientes de Zernike, RMS ("Root Mean Square") das aberrações de alta ordem e as aberrações dominantes foram comparados entre as condições sob cicloplegia e escotópica, e entre as condições escotópica e fotópica. RESULTADOS: O diâmetro da pupila foi 7,53 ± 0.69 mm sob a condição escotópica e atingiu a exigência de cerca de 6,5 mm de zona óptica na cirurgia baseada em análise de frentes de ondas, evitando erros de medição consequentes à mudança de centroide pupilar provocada por midriáticos. A dilatação farmacológica da pupila induziu aumento dos coeficientes de Zernike Z3-3, Z4(0) e Z5-5. As aberrações de mais alta ordem (terceira, quarta, quinta e sexta ordem) e a aberração esférica aumentaram de forma estatisticamente significativa, em comparação com a condição escotópica (P<0,010). Quando a condição escotópica se mudou para a condição fotópica, os coeficientes de Zernike Z4(0), Z4², Z6-4, Z6-2, Z6² e todas as aberrações de alta ordem diminuíram de forma estatisticamente significativa (P<0,010), demonstrando que a miose acomodativa pode significativamente melhorar a visão sob a condição fotópica. Sob as três condições, a aberração coma vertical apareceu mais frequentemente dentro das aberrações dominantes, sem influência significativa da variação do tamanho da pupila, e a proporção de aberração esférica diminuiu com a diminuição do tamanho da pupila. CONCLUSÕES: As aberrações de frente de onda são significativamente diferentes sob cicloplegia, condições escotópica e fotópica. O uso do sensor de frentes de onda (VISX WaveScan) para medir as aberrações de frente de onda escotópicas é uma opção viável para a cirurgia refrativa baseada em análise de frentes de onda.

Estrabismos: da teoria à prática, dos conceitos às suas operacionalizações / Strabismus: from theory to practice, from concepts to its operational attainment

Analisam-se particularidades inerentes ao estudo dos estrabismos, tais como as dificuldades para suas definições e os diferentes modos com os quais eles podem ser concebidos, a relatividade com que as posições binoculares possam ser interpretadas e os elementos referenciais necessários para a circunscrição dessas questões. A partir daí, discute-se o conceito de posição primária do olhar e as condições de sua operacionalização, concluindo-se pela impossibilidade de concretização desse ponto "zero", a partir do qual seriam feitas as medidas dos estrabismos e as quantificações de movimentos oculares. A seguir, passa-se ao exame da construção dos múltiplos sistemas referenciais aplicáveis à quantificação dos estrabismos, de cuja falta de consenso sobre qual deles usar decorrem implicações práticas elementares, como a falta de padronização do modo de superposição ortogonal de prismas, para a medida de desvios combinados, horizontal e vertical. Comenta-se a assimetria funcional das rotações oculares e suas exceções. Também se analisa a precisão com que se pode fazer a medida de um estrabismo, levando à conclusão sobre a impropriedade de uso de medidas fracionárias com as unidades angulares mais comumente usadas. Finalmente, são comentados alguns problemas técnicos dessas avaliações, tais como o das dificuldades operacionais relacionadas à dioptria-prismática, os subordinados ao uso de prismas e os da ocorrência de efeitos prismáticos pelo uso de lentes convencionais.

Some particular points concerning the study of strabismus are analyzed, specially, the difficulties for definitions and the different ways it can be conceived, besides the relativity of binocular positions interpretation, and the necessary referential elements for circumscribing such questions. Then, the concept of primary position of gaze is discussed as well as the conditions for its operational attainment, leading to the conclusion that it is materially impossible to achieve this "zero" point, from which all other measurements of strabismus or ocular movements should be done. In sequence, the construction of multiple referential systems applying the quantification of strabismus are examined. The lack of consensual agreement about which should be used as the standard system causes elementary practical implications, as the lack of agreement about how to superimpose orthogonal prisms for the measurement of associated horizontal and vertical deviations. The functional asymmetry of ocular rotations and its exceptions are commented. The accuracy that the measurements of strabismus can be performed is analyzed, leading to the conclusion that fractional figures using the commonest angular unities are improper. At last, some technical problems related to such evaluations are also commented, as operational difficulties related to prism-diopter unity, concerning the use of prisms, and prismatic effects due to the use of conventional optical glasses.