8,304 research outputs found

    Evaluation of progressive visual dysfunction and retinal degeneration in patients with parkinson’s disease

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    PURPOSE. To quantify changes in visual function parameters and in the retinal nerve fiber layer and macular thickness over a 5-year period in patients with Parkinson’s disease (PD). METHODS. Thirty patients with PD and 30 healthy subjects underwent a complete ophthalmic evaluation, including assessment of visual acuity, contrast sensitivity vision, color vision, and retinal evaluation with spectral-domain optical coherence tomography (SD-OCT). All subjects were reevaluated after 5 years to quantify changes in visual function parameters, the retinal nerve fiber layer, and macular thickness. Association between progressive ophthalmologic changes and disease progression was analyzed. RESULTS. Changes were detected in visual function parameters and retinal nerve fiber layer thickness in patients compared with controls. Greater changes were found during the follow-up in the PD group than healthy subjects in visual acuity, contrast sensitivity, Lanthony color test (P < 0.016), in superotemporal and temporal retinal nerve fiber layer sectors (P < 0.001), and in macular thickness (all sectors except inner superior and inner inferior sectors, P < 0.001). Progressive changes in the retinal nerve fiber layer were associated with disease progression (r = 0.389, P = 0.028). CONCLUSIONS. Progressive visual dysfunction, macular thinning, and axonal loss can be detected in PD. Analysis of the macular thickness and the retinal nerve fiber layer by SD-OCT can be useful for evaluating Parkinson’s disease progression

    Retinal nerve fiber layer abnormalities in Alzheimer's disease

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    Retinal nerve fiber layer (RNFL) photographs from 26 patients with Alzheimer's disease and 23 normal, age-matched, control subjects were reviewed for quality and abnormalities by two observers. A higher proportion of Alzheimer's patients showed RNFL abnormalities when compared to control subjects. There was some disagreement between the two observers regarding quality and frequency of abnormalities, reflecting suboptimal quality of the photographs obtained in patients with advanced Alzheimer's disease. Although these findings add to the clinical and histopathological evidence that ganglion cell degeneration occurs in Alzheimer's disease, the difficulty in obtaining and evaluating retinal nerve fiber layer photographs, especially in advanced cases, may limit the clinical usefulness of retinal nerve fiber layer analysis in such patients.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73257/1/j.1600-0420.1996.tb00090.x.pd

    Valores de Referência da Tomografia de Coerência Óptica na Idade Pediátrica

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    INTRODUCTION: Optical coherence tomography is a technology that allows obtaining high resolution images of tissues in vivo, enabling the measurement of ocular structures, including the retinal nerve fiber layer and macular thickness. As a noninvasive test itâÄôs particularly useful in children, but its applicability is limited by the existence of normative values for adults only. PURPOSE: To establish the pediatric normative values of retinal nerve fiber layer thickness and macular thickness and to investigate its relationship with sex, age, refraction, eye side and ocular dominance. MATERIAL AND METHODS: Ophthalmologic examination and Cirrus HD-optical coherence tomography (Carl Zeiss Meditec) were carried out on 153 children aged 4 to 17 years old. RESULTS: We obtained a mean retinal nerve fiber layer average thickness of 97.90 μm. No significant differences were detected between genders, however the eye side and ocular dominance had significant influence on retinal nerve fiber layer thickness. Retinal nerve fiber layer thickness increased significantly with more positive refraction. With the Macular Cube 512 x 128 protocol we found that the average central subfield showed the smallest thickness (250.35 μm) and boys had higher macular thickness. DISCUSSION: The values of the retinal nerve fiber layer thickness and macular thickness obtained are comparable to recent studies. The distribution of retinal nerve fiber layer thickness in quadrants is in agreement with the normal distribution of retinal nerve fiber layer. Macular thickness proved to be higher in males (center field and inner ring), data consistent with previous studies. CONCLUSION: We establish the normative retinal nerve fiber layer thickness and macular thickness in healthy Portuguese children. These data enhance the evaluation and interpretation of parameters obtained by optical coherence tomography in the diagnosis of pediatric disorders in clinical practice

    Comparison of retinal nerve fiber layer and macular thickness for discriminating primary open-angle glaucoma and normal-tension glaucoma using optical coherence tomography

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    Purpose The aim of this study was to evaluate the discrimination capabilities of macular and peripapillary retinal nerve fiber layer (pRNFL) thickness parameters as measured using spectral domain optical coherence tomography (SD-OCT) between primary open-angle glaucoma (POAG) and normal-tension glaucoma (NTG). Methods A total of 90 subjects were enrolled: 30 healthy subjects, 30 subjects with POAG and 30 subjects with NTG, consecutively. Retinal nerve fiber layer thickness, macular thickness and volume measurements were obtained with circular and radial SD-OCT scans. All parameters were compared between groups using an analysis of variance test. Areas under receiver-operating characteristic (AROC) curves with sensitivities at specificities greater than or equal to 90 per cent were generated to compare discrimination capabilities of various parameters between POAG and NTG. Results Macular thickness and volume measurements were the highest in normal subjects, followed by NTG and POAG (p < 0.05). Average retinal nerve fiber layer thickness had perfect discrimination for normal-POAG (AROC: 1.000; sensitivity: 100 per cent) and near perfect discrimination for normal-NTG (AROC: 0.979; sensitivity: 93 per cent) as well as NTG-POAG pairs (AROC: 0.900; sensitivity: 60 per cent). Inferior outer macular thickness (IOMT) and total volume were the best macular thickness and volume parameters having similar AROCs and sensitivities between normal and POAG (IOMT, AROC: 0.987; sensitivity: 92 per cent and total volume, AROC: 0.997; sensitivity: 97 per cent), normal and NTG (IOMT, AROC: 0.862, sensitivity: 47 per cent and total volume, AROC: 0.898, sensitivity: 67 per cent) and also between NTG and POAG (IOMT, AROC: 0.910, sensitivity: 53 per cent and total volume, AROC: 0.922, sensitivity: 77 per cent). In each comparison group, there was no statistically significant difference in AROCs between average retinal nerve fiber layer and inferior outer macular thickness, as well as total volume. Conclusions The macular parameters offer comparable performance to pRNFL parameters for the discrimination of NTG and POAG. Average retinal nerve fiber layer thickness, total macular volume and inferior outer macular thickness were the best SD-OCT parameters with superior discriminating capabilities

    COMPARISON BETWEEN AMBLYOPIC AND OTHER NON-AMBLYOPIC EYES IN TERMS OF MACULA AND RETINAL NERVE FIBER LAYER THICKNESS

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    Statement of Significance: The prospect of this study is that the macula thickness is reduced in amblyopic eyes and may be a potential diagnostic tool in the future screening of amblyopic eyes. We did the unilateral anisometropic amblyopic patient comparison between amblyopic and non-ambliopic eyes in terms of average macular thickness and average retinal nerve fiber layer thickness with the help of spectral optical coherens tomography. Material and Methods: The study included 74 over 6 year old patients with unilateral anisometropic amblyopia. Comparison between 74 amblyopic and 74 non-amblyopic eye in terms of average macular thickness and average retinal nerve fiber layer thickness, with the help of spectral optical coherens tomography (OPKO Instrumentations, Miami, FL). The difference between healthy and amblyopic eyes, mean macular thickness and retinal nerve fiber layer thickness were evaluated by Mann-Whitney U test. Results: The mean age of the patients was 9.46 ± 1.86 (7-14 years old) and 40 patients were female (54.05%), 34 patients were male (45.95%). Amblyopia group average macular thickness and mean retinal nerve fiber layer thickness respectively 235.31±21.3 micron (µ) and 100.96± 11.45 µ while non-amblyopia group average macular thickness and mean retinal nerve fiber layer thickness respectively 258.59±13.91 µ and 103.68±14.55 µ. Although statistically significant difference (p= 0.001) was observed with Mann-Whitney U test in terms of macular thickness, while in terms of retinal nerve fiber layer the difference between two groups was not statistically significant (p= 0,34). Conclusions: Average macular thickness measurements taken with OCT device varies in anisometropic amblyopic eyes is an important concept for future studies

    Efeito do comprimento axial ocular na espessura da camada de fibras nervosas da retina e da camada de células ganglionares-plexiforme interna avaliadas por OCT espectral

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    Purpose: To evaluate the influence of ocular axial length on circumpapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness in healthy eyes after correcting for ocular magnification effect. Methods: In this cross-sectional study, we evaluated 120 eyes from 60 volunteer participants (myopes, emmetropes, and hyperopes). The thickness of the circumpapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer were measured using the spectral optical coherence tomography (OCT)-Cirrus HD-OCT and correlated with ocular axial length. Adjustment for ocular magnification was performed by applying Littmann’s formula. Results: Before the adjustment for ocular magnification, age-adjusted mixed models analysis demonstrated a significant negative correlation between axial length and average circumpapillary retinal nerve fiber layer thickness (r=-0.43, p<0.001), inferior circumpapillary retinal nerve fiber layer thickness (r=-0.46, p<0.001), superior circumpapillary retinal nerve fiber layer thickness (r=-0.31, p<0.05), nasal circumpapillary retinal nerve fiber layer thickness (r=-0.35, p<0.001), and average ganglion cell-inner plexiform layer thickness (r=-0.35, p<0.05). However, after correcting for magnification effect, the results were considerably different, revealing only a positive correlation between axial length and temporal retinal nerve fiber layer thickness (r=0.42, p<0.001). . Additionally, we demonstrated a positive correlation between axial length and average ganglion cell-inner plexiform layer thickness (r=0.48, p<0.001). All other correlations were not found to be statistically significant. Conclusions: Before adjustment for ocular magnification, axial length was negatively correlated with circumpapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer thickness measured by Cirrus-OCT. We attributed this effect to ocular magnification associated with greater axial lengths, which was corrected with the Littman’s formula. Further studies are required to investigate the impact of ocular magnification correction on the diagnostic accuracy of Cirrus-OCT.Objetivo: Avaliar a influência do comprimento axial ocular na espessura da camada de fibras nervosas da retina peripapilar e na espessura da camada de células ganglionares-plexiforme interna em olhos saudáveis após correção para efeito de magnificação ocular. Métodos: Neste estudo transversal, avaliamos 120 olhos de 60 participantes voluntários (míopes, emétropes e hipermétropes). A espessura da camada de fibras nervosas da retina peripapilar e da camada de células ganglionares-plexiforme interna foram medidas usando a tomografia de coerência óptica espectral (OCT)-Cirrus HD-OCT e correlacionada com o comprimento axial ocular. O ajuste para a magnificação ocular foi realizado aplicando a fórmula de Littmann. Resultados: Antes do ajuste para magnificação ocular, a análise de modelos mistos ajustada por idade demonstrou uma correlação negativa significante entre o comprimento axial e a espessura média da camada de fibras nervosas da retina peripapilar (r=-0,43; p<0,001), espessura da camada de fibras nervosas da retina peripapilar inferior (r=-0,46; p <0,001), espessura da camada de fibras nervosas da retina peripapilar superior (r=-0,31; p<0,05), espessura da camada de fibras nervosas da retina peripapilar nasal (r=-0,35; p<0,001) e espessura média das células ganglionares-plexiforme interna (r=-0,35; p<0,05). No entanto, após a correção do efeito de magnificação, os resultados foram consideravelmente diferentes, revelando apenas uma correlação positiva entre o comprimento axial e a espessura temporal da camada de fibras nervosas da retina (r=0,42; p<0,001). Além disso, demonstramos uma correlação positiva entre o comprimento axial e a espessura média das células ganglionares-plexiforme interna (r=0,48; p<0,001). Todas as outras correlações não foram consideradas estatisticamente significativas Conclusão: Antes do ajuste para o efeito de magnificação ocular, o comprimento axial estava negativamente correlacionado com a espessura da camada de fibras nervosas da retina peripapilar e das células ganglionares-plexiforme interna medido pelo Cirrus-OCT. Atribuimos esse efeito à magnificação ocular associada a comprimentos axiais maiores, o que foi corrigido com a fórmula de Littman. Mais estudos são necessários para investigar o impacto da correção da magnificação ocular na acurácia diagnóstica do Cirrus-OCT

    Comparação entre as medidas da espessura da camada de fibras nervosas da retina e da mácula pela tomografia de coerência óptica na detecção da perda axonal progressiva decorrente à neuropatia óptica traumática

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    PURPOSE: To compare the optical coherence tomography retinal nerve fiber layer and macular thickness measurements for detection of progressive axonal loss following acute traumatic optic neuropathy in a longitudinal study. METHODS: Three patients with unilateral traumatic optic neuropathy were evaluated sequentially after trauma. Macular and retinal nerve fiber layer thickness measurements were obtained using optical coherence tomography weekly for five weeks and around the twelfth week after trauma. RESULTS: All patients showed progressive macular and retinal nerve fiber layer thickness reduction. The mean retinal nerve fiber layer thickness on the first week was 114 &#956;m and reduced sequentially over the first five weeks and was 46 &#956;m on the twelfth week. For macular parameters, the mean average thickness on the first week was 248 &#956;m and also reduced over the first five weeks and was 218 &#956;m on the twelfth week. When compared to the initial measurement, macular thickness average reduction rate at the 12th week was 14% while peripapillary retinal nerve fiber layer thickness average reduction rate was 59%. CONCLUSIONS: Although both measurements reduce significantly after trauma, retinal nerve fiber layer thickness measurements show greater and faster retinal neural reduction if compared to macular thickness measurements in traumatic optic neuropathy.OBJETIVO: Comparar as medidas da espessura da camada de fibras nervosas da retina e macular obtidas pela tomografia de coerência óptica na detecção da perda axonal progressiva após neuropatia óptica traumática aguda e durante o seguimento clínico. MÉTODOS: Três pacientes com neuropatia óptica traumática unilateral aguda foram avaliados sequencialmente após o trauma. Medidas da espessura macular e da camada de fibras nervosas da retina foram obtidas pela tomografia de coerência óptica semanalmente por 5 semanas consecutivas e ao redor da décima segunda semana após o trauma. RESULTADOS: Todos os pacientes apresentaram redução progressiva dos valores da espessura macular e da camada de fibras nervosas da retina. A espessura média da camada de fibras nervosas da retina foi de 114 &#956;m na primeira semana e reduziu sequencialmente ao longo das primeiras cinco semanas e foi de 46 &#956;m na décima segunda semana. Para parâmetros macular, a espessura média foi de 248 &#956;m na primeira semana, e também reduziu ao longo das primeiras cinco semanas e foi de 218 &#956;m na décima segunda semana. Quando comparado às medidas iniciais, a taxa de redução das médias da espessura macular foi 14% na décima segunda semana após o trauma, enquanto que a taxa de redução das médias da espessura da camada de fibras nervosas da retina foi 59%. CONCLUSÕES: Os valores da espessura da camada de fibras nervosas da retina apresentaram uma redução maior e mais rápida se comparada às medidas da espessura macular na neuropatia óptica traumática

    Retinal Nerve Fiber Layer Features Identified by Unsupervised Machine Learning on Optical Coherence Tomography Scans Predict Glaucoma Progression.

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    Purpose:To apply computational techniques to wide-angle swept-source optical coherence tomography (SS-OCT) images to identify novel, glaucoma-related structural features and improve detection of glaucoma and prediction of future glaucomatous progression. Methods:Wide-angle SS-OCT, OCT circumpapillary retinal nerve fiber layer (cpRNFL) circle scans spectral-domain (SD)-OCT, standard automated perimetry (SAP), and frequency doubling technology (FDT) visual field tests were completed every 3 months for 2 years from a cohort of 28 healthy participants (56 eyes) and 93 glaucoma participants (179 eyes). RNFL thickness maps were extracted from segmented SS-OCT images and an unsupervised machine learning approach based on principal component analysis (PCA) was used to identify novel structural features. Area under the receiver operating characteristic curve (AUC) was used to assess diagnostic accuracy of RNFL PCA for detecting glaucoma and progression compared to SAP, FDT, and cpRNFL measures. Results:The RNFL PCA features were significantly associated with mean deviation (MD) in both SAP (R2 = 0.49, P &lt; 0.0001) and FDT visual field testing (R2 = 0.48, P &lt; 0.0001), and with mean circumpapillary RNFL thickness (cpRNFLt) from SD-OCT (R2 = 0.58, P &lt; 0.0001). The identified features outperformed each of these measures in detecting glaucoma with an AUC of 0.95 for RNFL PCA compared to an 0.90 for mean cpRNFLt (P = 0.09), 0.86 for SAP MD (P = 0.034), and 0.83 for FDT MD (P = 0.021). Accuracy in predicting progression was also significantly higher for RNFL PCA compared to SAP MD, FDT MD, and mean cpRNFLt (P = 0.046, P = 0.007, and P = 0.044, respectively). Conclusions:A computational approach can identify structural features that improve glaucoma detection and progression prediction

    Comparison of retinal nerve fiber layer thinning and retinal ganglion cell loss after optic nerve transection in adult albino rats

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    We compared the time-course and magnitude of retinal nerve fiber layer (RNFL) thinning with that of retinal ganglion cell (RGC) loss after intraorbital optic nerve transection (IONT) in adult rats
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