Precise Montaging and Metric Quantification of Retinal Surface Area From Ultra-Widefield Fundus Photography and Fluorescein Angiography

Croft, Daniel E.; Hemert, Jano van; Wykoff, Charles C.; Clifton, David A.; Verhoek, Michael; Fleming, Alan; Brown, David M.

doi:10.3928/23258160-20140709-07

Cited by 79 publications

(54 citation statements)

References 13 publications

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“…In contrast, for the Jaccard and Sørensen-Dice similarity indices used in this study, such a scenario would result in low agreement. 7,8 …”

Section: Discussionmentioning

confidence: 99%

“…Prior publications have validated and described the manner by which the peripheral distortion inherent in UWF images can be overcome to allow precise quantification of retinal area from regions of interests within UWF images. 8 Limitations of this study include the retrospective design and sample size, although these limitations were partially mitigated by the use of standardized and rigorous masked evaluation of UWF images and angiograms, multiple masked graders, a reading center environment optimized for evaluating UWF images, standardized image acquisition protocol, and clinical trial-certified retinal imagers.…”

Section: Discussionmentioning

confidence: 99%

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Diabetic Retinopathy Severity and Peripheral Lesions Are Associated with Nonperfusion on Ultrawide Field Angiography

et al. 2015

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“…In contrast, for the Jaccard and Sørensen-Dice similarity indices used in this study, such a scenario would result in low agreement. 7,8 …”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Diabetic Retinopathy Severity and Peripheral Lesions Are Associated with Nonperfusion on Ultrawide Field Angiography

et al. 2015

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“…Poor image contrast, resulting from difficulties with the acquisition (e.g., inexact participant positioning), means the computational analysis of vessels is sometimes not achievable. After assessment, images deemed acceptable for analysis were stereographically projected, to compensate for distortions due to the retinal curvature and to enable the subsequent measurements made on the images in pixels to be converted to millimetre equivalents on the retina [34]. The operator then identified the region of interest in each image by masking out shadows caused by any eyelashes and areas of low contrast at the image edges, before enacting automatic segmentation of the vasculature [31].…”

Section: Methodsmentioning

confidence: 99%

Peripheral Retinal Imaging Biomarkers for Alzheimer’s Disease: A Pilot Study

et al. 2018

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Purpose: To examine whether ultra-widefield (UWF) retinal imaging can identify biomarkers for Alzheimer’s disease (AD) and its progression. Methods: Images were taken using a UWF scanning laser ophthalmoscope (Optos P200C AF) to determine phenotypic variations in 59 patients with AD and 48 healthy controls at baseline (BL). All living participants were invited for a follow-up (FU) after 2 years and imaged again (if still able to participate). All participants had blood taken for genotyping at BL. Images were graded for the prevalence of age-related macular degeneration-like pathologies and retinal vascular parameters. Comparison between AD patients and controls was made using the Student t test and the χ² test. Results: Analysis at BL revealed a significantly higher prevalence of a hard drusen phenotype in the periphery of AD patients (14/55; 25.4%) compared to controls (2/48; 4.2%) [χ² = 9.9, df = 4, p = 0.04]. A markedly increased drusen number was observed at the 2-year FU in patients with AD compared to controls. There was a significant increase in venular width gradient at BL (zone C: 8.425 × 10^–3 ± 2.865 × 10^–3 vs. 6.375 × 10^–3 ± 1.532 × 10^–3, p = 0.008; entire image: 8.235 × 10^–3 ± 2.839 × 10^–3 vs. 6.050 × 10^–3 ± 1.414 × 10^–3, p = 0.004) and a significant decrease in arterial fractal dimension in AD at BL (entire image: 1.250 ± 0.086 vs. 1.304 ± 0.089, p = 0.049) with a trend for both at FU. Conclusions: UWF retinal imaging revealed a significant association between AD and peripheral hard drusen formation and changes to the vasculature beyond the posterior pole, at BL and after clinical progression over 2 years, suggesting that monitoring pathological changes in the peripheral retina might become a valuable tool in AD monitoring.

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“…Images were processed by dewarping the standard UWFA images through transformation of the image into a stereographic projection of the eye, as previously described 11. The 3D model was mapped to a 2D stereographic projection by projecting all relevant pixels to a plane through the equator of the eye 11. Both native and dewarped images were analysed with the segmentation platforms.…”

Section: Methodsmentioning

confidence: 99%

Automated quantitative characterisation of retinal vascular leakage and microaneurysms in ultra-widefield fluorescein angiography

Ehlers

Wang

Vasanji³

et al. 2017

Br J Ophthalmol

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Summary Ultra-widefield fluorescein angiography (UWFA) is an emerging imaging modality used to characterize pathology in the retinal vasculature such as microaneurysms (MA) and vascular leakage. Despites its potential value for diagnosis and disease surveillance, objective quantitative assessment of retinal pathology by UWFA is currently limited because it requires laborious manual segmentation by trained human graders. In this report, we describe a novel fully automated software platform, which segments MAs and leakage areas in native and dewarped UWFA images with retinal vascular disease. Comparison of the algorithm to human grader generated gold standards demonstrated significant strong correlations for MA and leakage areas (ICC=0.78-0.87 and ICC=0.70-0.86, respectively, p=2.1×10-7 to 3.5×10-10 and p=7.8×10-6 to 1.3×10-9, respectively). These results suggest the algorithm performs similarly to human graders in MA and leakage segmentation and may be of significant utility in clinical and research settings.

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Precise Montaging and Metric Quantification of Retinal Surface Area From Ultra-Widefield Fundus Photography and Fluorescein Angiography

Abstract: By accounting for warping inherent in UWF images, precise montaging and accurate quantification of retinal surface area in square millimeters were achieved.

Cited by 79 publications

References 13 publications

Diabetic Retinopathy Severity and Peripheral Lesions Are Associated with Nonperfusion on Ultrawide Field Angiography

Diabetic Retinopathy Severity and Peripheral Lesions Are Associated with Nonperfusion on Ultrawide Field Angiography

Peripheral Retinal Imaging Biomarkers for Alzheimer’s Disease: A Pilot Study

Automated quantitative characterisation of retinal vascular leakage and microaneurysms in ultra-widefield fluorescein angiography

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