Inner retinal thickness and optic disc measurements in obese children and adolescents / Espessura retiniana interna e medidas do disco óptico na obesidade pediátrica

ABSTRACT Purpose: This study aimed to evaluate optic nerve head parameters and inner retinal layer thicknesses in obese children and adolescents. Methods: Forty-one eyes of 41 pediatric obese participants and 41 eyes of 41 age- and sex-matched healthy controls were included in this study. Body mass index was calculated, based on sex and age, using body weight and height measurements. Blood lipid values (i.e., cholesterol, low-density lipoprotein, high-density lipoprotein, and triglyceride) were measured in obese participants. Optical coherence tomography was used to examine optic nerve head parameters, including rim area, disc area, cup-to-disc ratio, and cup volume, as well as the thicknesses of retinal nerve fiber layers and macular ganglion cell-inner plexiform layers. Results: Optic disc parameters were similar in obese and healthy children (p>0.05). The percentage of binocular retinal nerve fiber layer thickness symmetry was significantly different between obese and control groups (p=0.003). Compared to the control group, participants in the obese group exhibited thinner retinal nerve fiber layers in the superior quadrants (p=0.04) and thinner ganglion cell-inner plexiform layers in the superior-temporal sectors (p=0.04). There were no statistically significant correlations between the ocular parameters and lipid blood test values assessed in this study (p>0.05). Body mass index was significantly negatively correlated with the mean retinal nerve fiber layer thickness (r=-0.33, p=0.03) in the obese group. There was no significant correlation between intraocular pressure and body mass index (r=0.05, p=0.74). Conclusion: Compared to healthy children, obese children had greater binocular retinal nerve fiber layer thickness asymmetry and thinner retinal nerve fiber and ganglion cell-inner plexiform layers in several sectors. Blood lipid levels were not associated with retinal thickness or optic disc parameters in obese children.

RESUMO Objetivo: O objetivo deste estudo foi avaliar os parâmetros da cabeça do nervo óptico e a espessura da camada interna da retina em crianças e adolescentes obesos. Métodos: Quarenta e um olhos de 41 participantes pediátricos obesos e 41 olhos de 41 controles saudáveis pareados por idade e sexo foram incluídos neste estudo. O índice de massa corporal foi calculado com base no sexo e na idade, utilizando medidas de peso e estatura corporal. Os valores de lipídios no sangue (colesterol, lipoproteína de baixa e alta densidade e triglicérides) foram medidos nos participantes obesos. A tomografia de coerência óptica foi usada para examinar os parâmetros da cabeça do nervo óptico, incluindo a área da borda, área do disco, razão escavação/disco, volume da escavação, espessura s camadas de fibra nervosa da retina e as camadas plexiformes internas das células ganglionares da mácula. Resultados: Os parâmetros do disco óptico foram semelhantes em crianças obesas e saudáveis (p>0,05). A porcentagem da simetria da espessura da camada de fibras nervosas da retina binocular foi significativamente diferente entre os grupos obesos e controle (p=0,003). Comparados ao grupo controle, os participantes do grupo obeso exibiram camadas mais finas de fibras nervosas da retina nos quadrantes superiores (p=0,04) e camadas plexiformes mais finas da célula ganglionar interna nos setores temporal superior (p=0,04). Não houve correlação significante entre os parâmetros oculares e os valores dos exames de sangue lipídico avaliados neste estudo (p>0,05). O índice de massa corporal foi significativamente correlacionado negativamente com a espessura média da camada de fibras nervosas da retina (r=-0,33, p=0,03) no grupo obeso. Não houve correlação significativa entre a pressão intraocular e o índice de massa corporal (r=0,05, p=0,74). Conclusão: Comparadas às crianças saudáveis, as crianças obe sas apresentaram maior assimetria binocular na espessura da ca mada de fibras nervosas da retina e fibras nervosas da retina mais finas e camadas plexiformes internas das células ganglionares em vários setores. Os níveis de lipídios no sangue não foram associados à espessura da retina ou aos parâmetros do disco óptico em crianças obesas.

Relationship between anterior segment and optic nerve head parameters in healthy subjects / Relações entre os parâmetros do segmento anterior e da cabeça do nervo óptico em indivíduos saudáveis

ABSTRACT Purpose: To determine the relationship between anterior segment and optic nerve head (ONH) parameters. Methods: Two hundred healthy subjects were enrolled in this study. The par­ticipants underwent measurement of anterior segment parameters with a Pentacam Scheimpflug system and imaging of the optic disc with confocal scanning laser ophthalmoscopy. Pearson's correlation coefficient was calculated to assess the associations between ONH and anterior segment parameters. Multivariate regression analyses controlling for age and disc area as confounding factors were also conducted. Results: There were significant negative relationships between optic disc area and corneal thickness (p=0.03, r=-0.217) and volume (p=0.017, r=-0.239). Corneal refractive power was significantly correlated with cup area, rim area, rim volume, and cup/disc ratio (p<0.05 for all). An increase of 1 diopter in anterior corneal refractive power corresponded to a decrease of 0.022 in cup/disc ratio. Rim volume was negatively correlated with anterior chamber depth and anterior chamber volume (p<0.05 for both). A 1-mm3 increase in anterior chamber depth corresponded to a 0.154-mm3 decrease in rim volume. Mean and maximum cup depth measurements were not associated with any of the anterior segment parameters. Conclusions: In nonglaucomatous eyes, the dimensions and shape of the ONH may be related to anterior segment morphology. Therefore, it may be helpful to take anterior segment parameters into consideration in evaluating the OHN.

RESUMO Objetivo: Determinar a relação entre os parâmetros do segmento anterior e da cabeça do nervo óptico (CNO). Métodos: Duzentos indivíduos saudáveis foram incluídos neste estudo. Os participantes foram submetidos à medição dos parâmetros do segmento anterior com o sistema Pentacam Scheimpflug e à obtenção de imagens de disco óptico com oftalmoscopia a laser de varredura confocal. O coeficiente de correlação de Pearson foi calculado para avaliar as associações entre CNO e os parâmetros do segmento anterior. Realizaram-se também análises de regressão multivariada que controlam a idade e a área do disco como factores de confusão. Resultados: Houve uma relação negativa estatisticamente significativa entre a espessura da córnea, o volume da córnea e a área do disco óptico (p=0,03, r=-0,217 e p=0,017, r=-0,239, respectivamente). As medições do poder de refração da córnea mostraram correlações significativas com a área da escavação, a área da rima, o volume da rima (RV) e a relação escavação/disco (C/D). (P<0,05 para todos). Um aumento de dioptria no poder de refração corneana anterior corresponde a uma diminuição de 0,022 em C/D. O RV mostrou correlação negativa com a profundidade da câmara anterior (PCA) e volume da câmara anterior. (P<0,05 para ambos). O aumento de 1 mm3 na PCA corresponde a uma diminuição de 0,154 mm3 no RV. As médias e as medidas máximas de profundidade de rima não mostraram associação com nenhum dos parâmetros do segmento anterior. Conclusões: Em olhos não glaucomatosos, as dimensões e forma da CNO podem estar relacionadas com a morfologia do segmento anterior. Portanto, pode ser útil levar em consideração os parâmetros do segmento anterior na avaliação da CNO.

Dynamic changes in optic disc morphology, choroidal thickness, anterior chamber parameters, and intraocular pressure during Valsalva maneuver / Mudanças dinâmicas na morfologia do disco óptico, espessura da coroide, parâmetros de câmara anterior e pressão intraocular durante a manobra de Valsalva

ABSTRACT Purpose: To investigate the effects of the Valsalva maneuver (VM) on optic disc morphology, choroidal thickness, and anterior chamber parameters. Methods: This prospective observational study included 60 eyes of 60 healthy subjects. The anterior chamber parameters, including central corneal thickness (CCT), anterior chamber depth (ACD), anterior chamber angle (ACA), anterior chamber volume (ACV), pupil diameter (PD), axial length (AL), subfoveal and peripapillary choroidal thickness, optic disc parameters, and intraocular pressure (IOP), were measured at rest and during VM. Results: VM did not have any significant influence on AL, subfoveal and peripapillary choroidal thickness, optic disc area, rim area, cup area, cup-to-disc area ratio, vertical cup-to-disc ratio, rim volume, cup volume, and nerve head volume measurements (for all; p >0.05). IOP and PD significantly increased during VM (for both; p <0.001). VM significantly decreased CCT, ACD, ACA, and ACV values (for all; p <0.001). Moreover, the optic nerve cup volume decreased and the horizontal cup-to-disc ratio significantly increased during VM (for both; p <0.05). Conclusions: VM may cause transient changes in IOP, optic disc morphology, and anterior chamber parameters.

RESUMO Objetivo: Investigar os efeitos da manobra de Valsalva (VM) sobre a morfologia do disco óptico, a espessura da coroide e parâmetros câmara anterior. Métodos: Estudo observacional, prospectivo incluiu 60 olhos de 60 indivíduos saudáveis. Os parâmetros da câmara anterior, incluindo da espessura central da córnea (CCT), profundidade da câmara anterior (ACD), ângulo da câmara anterior (ACA), volume de câmara anterior (ACV), diâmetro da pupila (PD), comprimento axial (AL), espessura da coroide subfoveal e peripapilar, parâmetros de disco óptico e pressão intraocular (IOP) foram medidos em repouso e durante VM. Resultados: A VM não apresentou influência significativa em AL, espessura da coroide subfoveal e peripapilar, área de disco óptico, área da rima neural, área da escavação, relação da área escavação-disco, a relação vertical escavação-disco, volume da rima neural, volume da escavação, medidas de volume cabeça do nervo (para todos; p >0,05). IOP e PD aumentaram significativamente durante VM (para ambos; p <0,001). A VM diminuiu os valores CCT, ACD, ACA e ACV significativamente (para todos; p <0,001). Além disso, o volume da escavação do nervo óptico diminuiu e a razão horizontal escavação-disco aumentou significativamente durante VM (para ambos; p <0,05). Conclusões: A VM pode causar alterações transitórias na pressão intraocular, na morfologia do disco óptico e em parâmetros câmara anterior.

Prevalence of disc cupping in non-glaucomatous eyes

This study assessed optic disc size and cupping, using a commercially available ophthalmoscope, in order to show norms of these values for clinical practice. Subjects were office-workers referred from their respective workplaces for a routine medical examination, which included eye examination. The optic disc size was classified as small, medium or large, for having a diameter < 1.0, 1.0-1.5, or > 1.5 times (respectively) the diameter of the ophthalmoscope's selected light spot on the posterior pole. The cupping was classified as the ratio of the vertical cupping diameter and the vertical disc diameter on a relative decimal scale from 0.0 to 1.0.This study included 184 subjects with a mean age of 40.5 ± 9.5 years; 149 (81%) were males. Their mean ocular pressure was 12.4 ± 1.5 mmHg (range 10-17 mmHg). There was a high correlation between optic disc sizes and cupping in the right and left eyes (Pearson Correlation r = 0.866, p < 0.001); therefore, for simplicity only the data for right eyes are presented. According to our definition, the optic discs in these eyes comprised 27 (14.7%) small, 141 (76.6%) medium and 16 (8.7%) large. The small optic discs were rarely cupped, and the large optic discs were always cupped. Optic disc cupping greater than 0.7 was rarely found and should be suspect of glaucoma. Clinical doctors should be aware of this and refer those subjects with abnormal cupping to the specialist.

Este estudio fue concebido para desarrollar normas clínicas sobre el tamaño y la excavación de la papila usando un simple oftalmoscopio en una población emétrope sin glaucoma. Los sujetos fueron oficinistas enviados al Centro Médico San Luis para un chequeo general de salud que incluye el examen oftalmológico. El tamaño de la papila o disco óptico fue clasificado en tres diámetros (pequeño, mediano y grande) comparando con el tamaño de la proyección retinal de la luz de un oftalmoscopio de bolsillo. La excavación papilar fue clasificada como la relación entre el diámetro horizontal de la excavación y el diámetro horizontal de la papila en escala decimal de 0.0 a 1.0. El estudio incluye 184 sujetos (edad media de 40.5 ± 9.5 años) y 149 (81%) fueron varones. Su presión ocular promedio fue de 12.4 ± 1.5 mmHg (entre 10-17 mmHg). La correlación tanto de los tamaños de disco óptico como de su excavación, fue alta entre ambos ojos (Correlación de Pearson, r = 0.866, p < 0.001) de modo que se presentan solamente datos de los ojos derechos. Según nuestra definición de tamaños papilares hubo 27 (14.7%) papilas pequeñas, 141 (76.6%) medianas y 16 (8.7%) grandes. Las papilas pequeñas rara vez tuvieron excavación y las grandes estuvieron siempre excavadas. Fue raro hallar papilas ópticas con una excavación mayor a 0.7, las que deberían hacer sospechar una lesión por glaucoma. Los clínicos avezados en oftalmoscopia deberían tener esto en cuenta para referir los sujetos con excavaciones grandes al especialista para su estudio oftalmológico.

Reproducibility of peripapillary retinal nerve fiber layer thickness measurements using Spectral Domain OCT in Brazilian patients / Reprodutibilidade da espessura da camada de fibras nervosas da retina utilizando-se o Spectral Domain OCT em pacientes brasileiros

PURPOSE: To evaluate the reproducibility of peripapillary retinal nerve fiber layer (RNFL) thickness measurements in normal eyes and eyes with glaucoma using spectral domain optical coherence tomography (SDOCT). METHODS: One eye of 79 normal and 72 glaucoma patients was analyzed. All patients underwent a complete ophthalmological examination, including visual acuity testing; intraocular pressure, slit-lamp examination, indirect ophthalmoscopy; and the glaucoma group underwent achromatic perimetry with the 24-2 SITA Fast Humphrey Field Analyzer. All patients' eyes were scanned using the spectral domain optical coherence tomography - Spectralis® and one of them was chosen randomly. Three consecutive circular B-scan centered at the optic disc were performed in one visit. RESULTS: The intraclass correlation coefficient (ICC), coefficient of variation and test-retest variability for the mean retinal nerve fiber layer thickness were respectively: 0.94, 2.56% and 4.85 µm for the normal group and 0.93, 4.65% and 6.61 µm for the glaucomatous group. The intraclass correlation coefficient for retinal nerve fiber layer thickness in all quadrants were all excellent in both groups, with the superior quadrant having the highest ICCs (0.964) in glaucomatous eyes and nasal quadrant measurements having the lowest (0.800), but still excellent in eyes without glaucoma. The coefficient of variation was between 2.56% - 8.74% and between 4.65% - 11.44% in normal and glaucomatous group respectively. The test-retest variability was between 4.85 µm and 11.51 µm in the normal group and between 6.61 µm and 14.24 µm in the glaucomatous group. The measurements in glaucomatous eyes were more variable than normal eyes. CONCLUSIONS: Spectral domain optical coherence tomography showed excellent reproducibility with regard to retinal nerve fiber layer thickness measurements in normal and glaucomatous eyes.

OBJETIVO: Avaliar a reprodutibilidade da medida da espessura da camada de fibras nervosas da retina (CFNR) em olhos sem e com glaucoma utilizando-se tomografia de coerência óptica de domínio espectral (spectral domain OCT - SDOCT). MÉTODOS: Foram analisados apenas um olho de 79 pacientes normais e 72 com glaucoma. Todos os pacientes realizaram um exame oftalmológico completo, incluindo acuidade visual, pressão intraocular, biomicroscopia, oftalmoscopia indireta e, para o grupo com glaucoma, perimetria acromática 24-2 SITA Fast Humphrey Field Analyzer. Foram realizados em todos os olhos e em apenas uma visita, três B-scans circulares centrados no disco óptico utilizando-se o SDOCT - Spectralis® RESULTADOS: O coeficiente de correlação intraclasse (ICC), coeficiente de variação e variabilidade teste-reteste para a média de espessura da camada de fibras nervosas da retina foram respectivamente: 0,94, 2,56% e 4,85 µm para o grupo sem glaucoma e 0,93, 4,65% e 6,61 µm para o grupo glaucomatoso. O coeficiente de correlação intraclasse foi excelente em ambos os grupos em todos os quadrantes, com o quadrante superior sendo o maior (0,964) no grupo glaucomatoso e o nasal sendo o menor (0,800), mas ainda excelente, em olhos sem glaucoma. O coeficiente de variação foi entre 2,56% - 8,74% e entre 4,65% - 11,44%, nos grupos sem e com glaucoma, respectivamente. A variabilidade teste-reteste variou de 4,85 µm e 11,51 µm no grupo sem glaucoma; e entre 6,61 µm e 14.24 µm no com glaucoma. Olhos com glaucoma apresentaram-se mais variáveis que os sem glaucoma. CONCLUSÃO: A tomografia de coerência óptica "spectral domain" apresentou excelente reprodutibilidade da espessura da camada de fibras nervosas da retina em pacientes sem e com glaucoma.

Morfometria comparativa entre discos ópticos de familiares de glaucomatosos e normais pelo HRTII / Heidelberg retina tomograph comparative measurements in relatives of glaucomatous patients and normal

OBJETIVO: Comparar discos ópticos de pacientes normais com história familiar de glaucoma primário de ângulo aberto (GPAA) com um grupo controle sem histórico familiar de glaucoma através da oftalmoscopia confocal a laser (HRTII). MÉTODOS: Análise retrospectiva da morfometria dos discos ópticos de pacientes com e sem história familiar de GPAA. Cada paciente foi submetido a exame oftalmológico completo, perimetria computadorizada, paquimetria e HRTII. Os pacientes foram classificados em três grupos de acordo com o grau de parentesco: primeiro grau (grupo 1), segundo grau (grupo 2) e grupo controle sem história familiar de glaucoma (grupo 3). Foram analisados: área total do disco óptico (Área Total), área de faixa neural (FxN), área da escavação (Esc.), relação escavação/disco (E/D) e relação E/D linear (L). Para a análise estatística, utilizou-se o programa SPSS 12.0. considerando-se apenas um dos olhos de cada paciente selecionado aleatoriamente. RESULTADOS: Foram incluídos setenta e quatro pacientes com idade média de 42,58 anos. Comparando-se os grupos 1 e 2, encontrou-se diferença estatisticamente significativa na variável Área Total, observando-se discos ópticos maiores no grupo 1. Comparando-se os grupos 1 e 3, as diferenças entre as variáveis Área Total, Esc, E/D e L foram estatisticamente significativas com predominância de valores mais elevados no grupo 1. Comparando-se os dados estereométricos entre os grupos 2 e 3 não foram encontradas diferenças de valores estatisticamente significantes. CONCLUSÃO: Pacientes normais parentes de primeiro grau de glaucomatosos apresentam maiores valores das variáveis topográficas do disco óptico quando comparados aos dos pacientes sem histórico familiar de glaucoma.

PURPOSE: To investigate whether there is a difference in topographic characteristics of optic nerve head analyzed by Heidelberg retina tomography (HRTII) in relatives of normal patients with or without history of open angle glaucoma. METHODS: Retrospective study analyzing the optic disc morphometry of normal patients with or without family history of glaucoma. Each participant underwent a routine examination, visual field testing, pachimetry and optic nerve head topography. Patients were classified according their family history of glaucoma in groups as first-degree (group 1), far second-degree (group 2) and no siblings with glaucoma (control group). Optic disc analyzed parameters were: disc area, rim area, cup area, cup/disc ratio (E/D) and linear cup/disc ratio. Statistical analysis was made through the SPSS 12.0 program considering only one randomized eye. A P value of less than 0.05 was considered statistically significant. RESULTS: Seventy-four patients (74 eyes) were included. The average age was 42.58 years. In the stereometric analysis, the comparison between the disc area from the group 1 and group 2 was statistically significant (P < 0.005), with marked overlap in group 1, fact that was repeated for the variables disc area, cup area, cup/disc ratio linear cup/disc ratio comparing first -degree and control group. There was no statistical difference comparing group 2 and 3 in the stereometric analysis. CONCLUSION: First-degree siblings of glaucoma patients present stereometric differences in optic disc when compared with patients without history of glaucoma. These differences were found in patients with no signs of the disease.

Simulated cup/disc ratio: a tool for ophthalmologists / Razão escavação/disco simulada: uma ferramenta para oftalmologistas

PURPOSE: To evaluate and compare the observers' ability to measure simulations of cup/disc ratios (CDR) as concentric and non-concentric circles. METHODS: In a prospective, random, and masked setting, 43 images representing the CDR spectrum from 0.2 to 0.9 for vertical and horizontal CDR measurements were developed and presented on a computer screen to 171 participants. RESULTS: There were satisfactory agreements according to the kappa coefficient (0.755 and 0.730 for horizontal and vertical cup disc ratios, respectively) and Lin's concordance correlation (R=0.88 and R=0.86 for horizontal and vertical measurements, respectively). However, very poor agreement was found for intermediate CDR values. The worst agreement occurred when the CDR was between 0.4 and 0.6 for both the horizontal and vertical values. The kappa coefficient was 0.37 and 0.39 for 0.4 CDR (horizontal and vertical, respectively), 0.39 and 0.38 for 0.5 CDR (horizontal and vertical, respectively) and 0.45 and 0.41 for 0.6 CDR (horizontal and vertical, respectively). CONCLUSION: Despite a good general agreement between the gold standard and the participants' responses, the absolute agreement for intermediate CDR values was very poor for both horizontal and vertical values.

OBJETIVO: Avaliar e comparar a habilidade de observadores em medir a razão escavação/disco (CDR) por meio de figuras esquemáticas. MÉTODOS: Em um estudo prospectivo, randomizado e mascarado, 43 imagens representado CDR horizontais e verticais entre 0,2 e 0,9 foram desenvolvidas e apresentadas em uma tela de computador para 171 participantes. RESULTADOS: Para todos os intervalos de CDR a concordância foi satisfatória para análise kappa (0,755 e 0,730 para CDR horizontais e verticais, respectivamente) e para concordância de Lin (R=0,88 e R=0,86 para medidas horizontais e verticais respectivamente). No entanto, a concordância foi fraca para valores intermediários de CDR. A pior concordância ocorreu para CDR horizontais e verticais entre 0,4 e 0,6. CONCLUSÃO: Apesar da boa concordância geral entre as respostas corretas e as respostas dadas pelos participantes, a concordância absoluta para valores intermediários de CDR mostrou-se muito fraca tanto para figuras horizontais como verticais.

Factors affecting the variability of the Heidelberg Retina Tomograph III measurements in newly diagnosed glaucoma patients / Fatores associados com a variabilidade das medidas do Heidelberg Retina Tomograph III em pacientes com glaucoma recém-diagnosticados

PURPOSE: To determine factors associated with the test-retest variability of optic nerve head (ONH) topography measurements with confocal scanning laser ophthalmoscopy (CSLO) in newly diagnosed glaucomatous patients. METHODS: Consecutive patients with newly diagnosed primary open-angle glaucoma were prospectively enrolled. Patients presenting with any ocular disease other than glaucoma were excluded. All patients underwent CSLO using the Heidelberg Retina Tomograph III (HRT-III) in one randomly selected eye (three consecutive scans; performed by the same examiner). For each Heidelberg Retina Tomograph III parameter, repeatability was assessed using within subject standard deviation (Sw) and coefficient of variation (CVw), repeatability coefficient (RC) and intraclass correlation coefficient (ICC). Scatter plots and regression lines were constructed to identify which factors influenced test-retest measurement variability. RESULTS: A total of 32 patients were included (mean age, 65.4 ± 13.8 years). Most patients were female (65 percent) and white (50 percent). Among all Heidelberg Retina Tomograph III parameters evaluated, rim area and mean cup depth had the best measurement repeatability. Vertical cup-to-disc ratio (CDR, as determined by optic disc stereophotograph examination) was significantly associated (R²=0.21, p<0.01) with test-retest measurement variability. Eyes with larger CDR showed less variable measurements. Other factors, including age, disc area, central corneal thickness and intraocular pressure were not significant (p>0.14). CONCLUSION: Heidelberg Retina Tomograph III showed good test-retest repeatability for all ONH topographic measurements, mainly for rim area and mean cup depth. Test-retest repeatability seemed to improve with increasing CDR. These findings suggest that HRT-III topographic measurements should be cautiously interpreted when evaluating longitudinally glaucoma patients with early structural damage (small CDR).

OBJETIVO: Determinar os fatores associados à variabilidade (teste-reteste) das medidas topográficas da cabeça do nervo óptico (CNO) utilizando a oftalmoscopia confocal de varredura a laser (CSLO) em pacientes com glaucoma recém-diagnosticados. MÉTODOS: Neste estudo, pacientes com glaucoma primário de ângulo aberto recém-diagnosticados foram prospectivamente incluídos. Aqueles que apresentassem outras doenças oculares (exceto glaucoma) foram excluídos. Todos os pacientes incluídos no estudo foram submetidos à CSLO usando o aparelho Heidelberg Retina Tomograph III (HRT-III) em um olho aleatoriamente selecionado (três exames consecutivos realizados pelo mesmo examinador). Para cada parâmetro do Heidelberg Retina Tomograph III, a repetibilidade foi avaliada através dos seguintes indicadores: desvio padrão (DP) e coeficiente de variação (CV) individual, coeficiente de repetibilidade (CR) e coeficiente de correlação intraclasse (CCI). Diagramas de dispersão e linhas de regressão foram construídos para identificar quais fatores poderiam influenciar a variabilidade das medidas. RESULTADOS: Trinta e dois pacientes foram incluídos no estudo (idade média, 65,4 ± 13,8 anos). A maior parte era composta por mulheres (65 por cento) e pacientes brancos (50 por cento). Dentre os parâmetros de Heidelberg Retina Tomograph III avaliados, a área da rima e a profundidade média da escavação apresentaram os melhores valores de repetibilidade. A relação escavação/disco (E/D) vertical (baseada na análise de estereofotografia do disco óptico), foi significativamente associada (R²=0.21, p<0.01) com a variabilidade teste-reteste. Pacientes com relação E/D maiores apresentaram medidas menos variáveis. Outros fatores como idade, área do disco, espessura corneana central e pressão intraocular não foram significativas (p>0,14). CONCLUSÃO: O Heidelberg Retina Tomograph III mostrou boa repetibilidade (teste-reteste) para todos os parâmetros topográficos da CNO avaliados, principalmente em relação à área da rima e à profundidade média da escavação. A repetibilidade teste-reteste apresentou melhores resultados com o aumento da relação E/D. Esses achados sugerem que as medidas topográficas do Heidelberg Retina Tomograph III devem ser interpretadas com cautela quando avaliarmos longitudinalmente pacientes glaucomatosos com dano estrutural inicial (relação E/D menor).

Assimetria na relação escavação/disco óptico em adolescentes / Cup-to-disc ratio asymmetry in adolescents

Objetivo: Verificar a frequência de assimetrias superiores a 0,2 na razão escavação/disco em uma população de adolescentes. Métodos: Retinografias de ambos os olhos de 123 jovens foram digitalizadas na resolução de 300 pixels por polegada (300 dpi), 8 bits, padrão de cor RGB. Para a realização das medidas foi utilizado o software Image J, versão 1.42, desenvolvido pelo National Institute of Health (NIH), plataforma Java versão 1.6. Resultados: Os valores das diferenças, entre os dois olhos do mesmo indivíduo, na razão das medidas do diâmetro vertical da escavação/diâmetro vertical do disco óptico variaram de 0 a 0,30. A média das diferenças foi 0,07, a mediana 0,06 e o desvio padrão 0,05. Assimetrias de até 0,06 apresentaram frequência de 54,4 por cento e assimetrias de até 0,1 estiveram presentes em 79,7 por cento da amostra. Dois indivíduos (1,63 por cento) apresentaram assimetrias superiores a 0,2. Conclusão: A frequência de assimetrias no grupo de adolescentes estudado é similar à encontrada em estudos realizados com população adulta normal.

Purpose: To determine the frequency of asymmetries greater than 0.2 in the cup-to-disc ratio of a population of adolescents. Methods: Fundus photographs of both eyes of 123 adolescents were digitized at the resolution of 300 pixels per inch (300 dpi), 8 bits, with a RBG color pattern. The measurements were performed using the Image J software, version 1.42, developed by the National Institutes of Health (NIH), Java platform version 1.6. Results: The values of the differences in the cup-to-disc ratio between the two eyes of the same individual ranged from 0 to 0.30. The mean difference was 0.07, the median 0.06 and the standard deviation 0.05. About 54.4 percent of the studied population had asymmetries up to 0.06 and 79.7 percent had asymmetries up to 0.1. Two individuals presented asymmetries of more than 0.2, corresponding to 1.63 percent of the evaluated subjects. Conclusion: The frequency of asymmetries in the group of adolescents studied was similar to that detected in studies of the normal adult population.

Normative data of optic nerve head in Thai population by laser scanning tomography: Siriraj study.

OBJECTIVE: To study the normative values of topographic optic disc parameters in a Thai population. MATERIAL AND METHOD: Two hundred and six eyes of 103 normal subjects aging from 30-80 years were studied Thirteen topographic disc parameters were analyzed by confocal scanning laser ophthalmoscope using Heidelburg retina tomography (HRT II). The average value of two eyes in the same subject was used as the unit of statistical analysis, and then the normal values and means were statistically calculated at 95% reference interval (95% RI). Ethnic differences of the calculated optic nerve topography were compared with previous studies. The relationship of age, intraocular pressure (IOP), central corneal thickness (CCT), and optic disc parameters were assessed by Pearson correlation. RESULTS: Mean values with 95% RI of all 13 parameters were analyzed Whole parameters except cup volume demonstrated normal distribution. Mean value (95% RI) of disc area in normal Thai people was 2.67 mm2 (1.96, 3.71) which was larger than Caucasian people. Ethnic differences in topographic optic disc parameters were found among Thai and other races including Asians, Caucasians, African-Americans, and Hispanics. The results also revealed that age, IOP, and CCT had no significant relation to all optic disc parameters. CONCLUSION: Thai people had a larger optic disc area than Caucasians. There are marked differences of topographic optic nerve parameters among different ethnic groups. These differences need to be taken into account when evaluating glaucomatous optic neuropathy and when comparing results of studies completed among population of different ethnic and racial origins.

Anterior ischemic optic neuropathy: a comparison of the optic disc area of patients with the arteritic and non-arteritic forms of the disease and that of normal controls

PURPOSE: To evaluate the optic disc area of patients with non-arteritic anterior ischemic optic neuropathy (NA-AION) and arteritic anterior ischemic optic neuropathy (A-AION) and compare the results between each other and with those from controls in order to verify the existence and the magnitude of anatomical factors predisposing to the development of anterior ischemic optic neuropathy. METHODS: This is a case-controlled study of the optic disc area of 24 consecutive patients affected with NA-AION, 13 patients with A-AION and 24 consecutive healthy normals, sex- and age-matched with the patients with the NA-AION group. Measurements of optic disc area were performed for each studied group using disc photographs projected, measured and corrected for the refractive error and the keratometric readings, according to Littmann's method in each studied group. The results were compared using variance analysis. RESULTS: The mean areas and standard deviations of the optic discs from patients with NA-AION, A-AION and normals were respectively 1.99 ± 0.35 mm², 2.29 ± 0.39 mm² and 2.49 ± 0.53 mm². The statistical analysis revealed that the mean areas of the optic disc of patients with NA-AION were significantly different from those of normal controls. No statistical difference was found between A-AION and normal controls. CONCLUSION: NA-AION occurs predominantly in small discs while the arteritic form of the disease shows no such preference. Factors related to optic disc structure play a role in the pathophysiology of NA-AION. The occurrence of AION in large optic optic discs should raise the suspicion of temporal arteritis. On the other hand, small optic disc areas do not rule out that vasculitis.

OBJETIVO: Calcular a área do disco óptico de pacientes com neuropatia óptica isquêmica anterior não arterítica (NOIA-NA) e com neuropatia óptica isquêmica anterior por arterite temporal (NOIA-A) comparando os resultados entre si e com o grupos controle para verificar a existência e a magnitude de fatores anatômicos predisponentes ao desenvolvimento da neuropatia óptica isquêmica anterior. MÉTODOS: Estudo prospectivo, caso-controle das áreas dos discos ópticos de 24 pacientes acometidos por NOIA-NA, 13 com NOIA-A e 24 indivíduos controles normais. As medidas da área do disco óptico foram realizadas a partir de retinografias projetadas, sendo as medidas corrigidas levando em conta o erro refracional e a ceratometria de acordo com o método de Littmann em cada um dos grupos estudados. Os resultados foram comparados usando-se análise de variância. RESULTADOS: Os valores médios e desvios-padrão para as áreas do disco óptico dos olhos com NOIA-NA, NOIA-A e normais foram respectivamente de 1,99 ± 0,35 mm²; 2,29 ± 0,39 mm² e 2,49 ± 0,53 mm². A análise estatística revelou diferença significativa entre o grupo de olhos de pacientes com NOIA-NA e os controles normais. Não houve diferença significativa entre os olhos com NOIA-A e os controles. CONCLUSÕES: A forma não arterítica da NOIA ocorre em olhos com discos ópticos pequenos, ao passo que a forma arterítica da doença não mostra esta preferência. Fatores anatômicos estruturais do disco óptico têm um papel importante na fisiopatogenia da NOIA-NA. A ocorrência de NOIA em disco óptico de grandes dimensões deve reforçar a suspeita de arterite temporal. Discos ópticos pequenos, por outro lado não permitem excluir aquela vasculite.

Trabeculectomy and optic nerve head topography

The objective of the present study was to evaluate changes in optic nerve head parameters, measured by confocal laser tomography, before and after trabeculectomy in order to identify outcome measures for the management of glaucoma. The optic nerve head of 22 eyes (22 patients) was analyzed by confocal laser tomography with the Heidelberg retinal tomogram (HRT) before and after trabeculectomy. The median time between the first HRT and surgery was 4.6 months (mean: 7.7 ± 8.3) and the median time between surgery and the second HRT was 10.8 months (mean: 12.0 ± 6.8). The patients were divided into two groups, i.e., those with the highest (group A) and lowest (group B) intraocular pressure (IOP) change after surgery. Differences in the 12 standard topographic parameters before and after surgery for each group were evaluated by the Wilcoxon signed rank test and the differences in these parameters between the two groups were compared by the Mann-Whitney rank sum test. Multiple regression analysis was used to evaluate the influence of the change in IOP (deltaIOP and deltaIOP percent) and the changes in the other parameters. There were significant differences in the HRT measures before and after surgery in group A only for cup volume. In group B, no parameter was statistically different. The changes in group A were not significantly different than those in group B for any parameter (P > 0.004, Bonferroni correction for multiple comparisons). deltaIOP and deltaIOP percent had a statistically significant effect on delta cup disk area, delta cup volume and delta mean cup depth. Changes in cup shape size were influenced significantly only by deltaIOP. Some optic disc parameters measured by HRT presented a significant improvement after filtering surgery, depending on the amount of IOP reduction. Long-term studies are needed to determine the usefulness of these findings as outcome measures in the management of glaucoma.

Correlation of confocal laser scanning tomography with planimetric photographic measurements of the optic disc in a normal South Indian population: the Vellore Eye Study.

PURPOSE: To compare the confocal laser tomographic scanning evaluation with photographic measurements of the optic nerve head in a South Indian population. METHODS: The prospective comparative clinical non-interventional epidemiologic study included 62 subjects (62 eyes) forming a population-based sample, selected randomly. Mean age was 47.2 +/- 8.9 years, mean refractive error measured was -0.17 +/- 1.10 diopter (range, - 4.50 to + 2.50 diopter). Confocal laser scanning tomographic images on Heidelberg Retina Tomograph (HRT) and colour optic disc photographs were morphometrically analysed and compared. Main outcome measures were morphologic optic disc parameters. RESULTS: The optic disc area measurements were significantly smaller (p < 0.001) in the HRT technique than in the photographic method. In contrast, the HRT as compared to the photographic measurements showed significantly (p < 0.001) larger values for the relative width and relative area of the neuroretinal rim. The differences in measurements between both methods were maximum in the nasal part (p < 0.001) of the optic disc and minimum in the temporal disc region. CONCLUSION: In normal eyes of South Indians, neuroretinal rim measurements by the HRT and expressed as percentage of disc size measurements are significantly larger than rim measurements on disc photographs.

The normal optic nerve head on Heidelberg Retina Tomograph II.

PURPOSE: To study the characteristics of the optic nerve head using a scanning laser ophthalmoscope, the Heidelberg Retina Tomograph II (HRT II), in a normal population and to determine the specificity of HRT II diagnostic indices in the study population. METHODS: The optic nerve heads from 275 consecutive, randomly selected normal subjects were imaged on HRT II. Stereometric parameters were studied with respect to baseline variables such as age, gender, refractive error and disc size. The stereometric parameters and the results of Moorfields regression analysis (MRA) and discriminant function analysis were recorded. RESULTS: The average disc size in the population under study was 2.34 +/- 0.47 mm2. Age and gender had no significant effect on stereometric parameters. Myopic discs were larger than hypermetropic discs. MRA had a specificity varying between 85.5% and 98.2% depending upon the criteria used to define an abnormal disc. The specificity of MRA decreased with increasing disc size. The RB (R Bathija) and FSM (F S Mikelberg) discriminant functions had specificities of 96.4% and 87.3% respectively. CONCLUSIONS: Estimation of stereometric parameters of a normal disc can be used to indicate an abnormal one. Moorfields regression analysis and discriminant functions have a high specificity in our normal population; however caution must be exercised in interpreting the results for a disc area larger than 3 mm2.

Avaliação da influência dos parâmetros topográficos do disco óptico, do diâmetro ântero-posterior do olho, da raça e do erro refracional sobre a medida da espessura da camada de fibras nervosass da retina de indivíduos normais / Influence of optic disc topographic parameters obtained with scanning laser ophthalmoscope, axial diameter of the eye, race, and refration, on the nerve fiber layer thickness measurements obtained with scanning laser polarimetry in normal subjects

Avaliou-se a influência dos parâmetros topográficos do disco óptico obtidos com laser de varredura, do diâmetro ântero-posterior do olho, da raça e do erro refracional sobre a medida da espessura da camada de fibras obtida com o laser confocal polarizado em indivíduos normais. Cento e um indivíduos normais foram incluídos no estudo. Constatou-se fraca correlação (r=0,226) entre a área da rima neuro-retiniana setor nasal com a espessura média no setor nasal da CFN da retina (NA) (p=0,023)., bem como, entre entre o parâmetro a espessura média no setor inferior da CFN da retina (IA) e o diâmetro ântero-posterior do olho (r=0,209, p=0,038). Não houve diferença estatisticamente significante entre raça e erro refracional sobre os valores da espessura da camada de fibras nervosas. Estes achados sugerem que, do ponto de vista clínico, não há influência do DAP, da raça, do erro refracional e dos parâmetros do disco óptico estudados sobre as medidas da espessura da CFN obtidas co LCP em indivíduos normais / This study evaluated the influence of optic disc topographical obtained with scanning laser ophthalmoscope, axial diameter of the eye, race, and refraction, on the nerve fiber layer thickness measurements obtained with scanning laser polarimetry in normal subjects. One hundred and one normal subjects were included in the study. A subtle relation was noticed (r=0,226) between the nasal neuroretinal rim área, obtained with scanning laser ophthalmoscope, and the mean nasal nerve fiber layer thickness (p=0.0023), obtained with scanning laser polarimetry. There was a subtle relation (r=0,209 p=0.038) between the the mean inferior nerve fiber layer thickness, obtained with scanning laser polarimetry, and the diameter of the eye. The refractional errors values were not shown to have a linear relation with the nerve fiber thickness values. There was no statistically significant difference between race and the nerve fiber layer thickness values. These findins suggest that, in clinical settings, there is no influence of axial diameter, race, refractional errors and disc optic topographic measurements on the retina fiber layer thickness measurements, obtained with the polarimetry in normal subjects...

Interocular comparison of nerve fiber layer thickness and its relation with optic disc size in normal subjects

We conducted an investigation of the relation between RNFL thickness and optic disc size along with an interocular comparison of optic disc size, RNFL thickness, and RNFL density in healthy subjects. A total of 64 normal eyes from 32 Korean volunteers were enrolled in this study. A GDx Nerve Fiber Analyzer with software version 2.0.09 was used to image all subjects. Optic disc size was measured by pi x (horizontal radius) x (vertical radius). The RNFL density of each quadrant was calculated by dividing each quadrant integral by the total integral. Optic disc size was positively correlated with the total RNFL thickness (r = 0.615, p < 0.01). Optic disc size and RNFL density were inversely related in the superior quadrant (r = -0.248, p < 0.05). There was a significant positive correlation between optic disc size and RNFL density in the nasal quadrant (r = 0.439, p < 0.01) and the temporal quadrant to a certain degree. A significant positive correlation was found between the right and left eyes in terms of total RNFL thickness in and that of each quadrant. Interocular RNFL density was positively correlated in both the temporal and nasal quadrants. These findings must be considered when one evaluates and compares RNFL measurements between two eyes as is often the case where both eyes are usually affected in the course of glaucomatous RNFL damage.

Planimetric optic disc parameters in normal eyes: a population-based study in South India.

PURPOSE: To study the optic disc parameters of normal eyes in a population-based south Indian study. METHODS: One hundred and fifty three subjects from a population-based sample of 1060 included in the Andhra Pradesh Eye Disease Survey (APEDS) were enrolled in the optic disc study. The male-female ratio, the refractive error and distribution of other ocular parameters in the disc study subjects and the APEDS were not significantly different. Magnification corrected morphometry of optic disc photographs obtained by Zeiss telocentric fundus camera was carried out in one randomly chosen eye of each of these 143 subjects. RESULTS: The mean optic disc parameters with the 95% confidence intervals for the distribution were: disc area 3.37 mm2 (2.04 - 4.7), vertical disc diameter 2.12 mm (1.67 - 2.57), vertical cup to disc ratio 0.37 (0.19 -0.55) and neuroretinal rim area 2.8 mm2 (1.76 - 3.84). The disc area, the vertical cup to disc ratio and the rim area showed a normal distribution. The cup to disc ratio correlated with the vertical disc diameter but the association was not strong. CONCLUSION: The disc area, the vertical cup to disc ratio and the neuroretinal rim area are normally distributed in the South Indian population. The normal optic disc parameters would form a basis for future comparisons in different forms of glaucoma.

Exame digitálico da papila e fibras nervosas retinianas / Digital examination of the optic disc and the retinal nerve fiber layer

Quando olhamos uma imagem oftalmológica, nós a vemos através do nosso aparelho visual. Quando esta mesma imagem é analisada pelo computador, ele utiliza parâmetros diferentes de avaliaçäo e o seu resultado gráfico revela uma outra face da imagem oculta à visäo convencional. O atual trabalho aplica praticamente estes conceitos e avalia digitalmente a papila e feixes de fibras nervosas retinians (RNFL). A importância do tema, a lesäo das células ganglionares procede o aparecimento de defeitos na campimetria. Sinteticamente utilizamos o seguinte material: CR5-45NM Canon - retinal camera non-mydriatic; video câ,mera Sony 3CCD; placa digital de captura MIRO DC20 (captura a imagem do flash); software para estudo de imagens: N.I.H. (National Institute of Health U.S.A.), utilizado para a

development of the retina and optic stak in rat embryos

This work was done to study the prenatal development of the retina and optic chiasma in albino rat embryos in an attempt to provide the mechanism of optic axonal guidance and to elucidate the relation between the cytodifferentation of the retina and its central nervous connection. Thirty rat embryos in age from 12 days to 21 days [full term newborn], were used in this study. The results of the present work indicate that the projection of the outgrowing axons araised from the early developing ganglion cells and extend in the direction of the optic dise has occurred through the extracellular spaces, which formed inside the superficial portion of the retina during the early period of generation. Moreover, the findings of this work suggest that the origin of the retinal macroglial cells [astrocytes] is the neuroepithelial cells of the optic stalk that reach the retina through its blood vessels. Theses cells together with the developing glial cells derived from the floor of dienecphalon are emphasized to act as candidates for guidance of the nerve axons within the retina, optic stalk and optic stalk prior to penetration of the axons are postulated to minimize the resistance of axonal advance through the stalk providing a potential path for the growing axons to reach the diencephalons. This was followed by concomitant maturation of the ganglion cells and differentiation of the inner plexiform layer of retina during the late stages of gestation

A propósito de uma alternativa para medida das lesöes maculares / An alternative proposition to mesure macular lesions

Uma técnica alternativa para medida das lesöes maculares é proposta. O método consiste na medida das lesöes através da largura do feixe luminoso. A fenda luminosa é diminuida gradativamente até que ocupe a margem da lesäo de ambos os lados. Em seguida a leitura é feita no braço da lâmpada de fenda na escala milimetrada. O aparelho utilizado foi da marca Topcon modelo SLE-6, que possui escala com diferença de um milímetro entre as medidas. Foi também comparada esta medida com o diâmetro papilar onde se constatou que 1/3 do diâmetro equivaleria à largura média de 8,25 mm da fenda luminosa