Analysis of the choroidal vascularity in asymmetric pseudoexfoliative glaucoma using optical coherence tomography-based image binarization

Eye ◽  
2021 ◽  
Author(s):  
Mert Simsek ◽  
Onur Inam ◽  
Emine Sen ◽  
Ufuk Elgin
2020 ◽  
Vol 61 (4) ◽  
pp. 18 ◽  
Author(s):  
Zhouyue Li ◽  
Wen Long ◽  
Yin Hu ◽  
Wenchen Zhao ◽  
Wen Zhang ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alessandro Arrigo ◽  
Emanuela Aragona ◽  
Andrea Saladino ◽  
Alessia Amato ◽  
Francesco Bandello ◽  
...  

AbstractOptical coherence tomography angiography (OCTA) provides several data regarding the status of retinal capillaries. This information can be further enlarged by employing quantitative metrics, such as vessel density (VD). A mandatory preliminary step of OCTA quantification is image binarization, a procedure used to highlight retinal capillaries on empty background. Although several binarization thresholds exist, no consensus is reached about the thresholding technique to be used. In this study, we tested thirteen binarization thresholds on a dataset made by thirty volunteers. The aim was to assess the impact of binarization techniques on: (I) detection of retinal capillaries, assessed by the calculation of overlapping percentages between binarized and original images; (II) quantitative OCTA metrics, including VD, vessel tortuosity (VT) and vessel dispersion (Vdisp); (III) foveal avascular zone (FAZ) detection. Our findings showed Huang, Li, Mean and Percentile as highly reliable binarization thresholds (p < 0.05), whereas the worst binarization thresholds were Intermodes, MaxEntropy, RenylEntropy and Yen (p < 0.05). All the thresholds variably underestimated VD metric and FAZ detection, with respect to the original OCTA images, whereas VT and Vdisp turned out to be more stable. The usage of a Fixed threshold resulted extremely useful to reduce VD and FAZ underestimations, although bound to operators’ experience.


Retina ◽  
2018 ◽  
Vol 38 (3) ◽  
pp. 508-515 ◽  
Author(s):  
Jorge Ruiz-Medrano ◽  
José M. Ruiz-Moreno ◽  
Abhilash Goud ◽  
Kiran Kumar Vupparaboina ◽  
Soumya Jana ◽  
...  

Author(s):  
Eddine Jouini Dhia ◽  
I. M. Bezkorovaуna

Glaucoma is one of the leading causes of blindness and disability worldwide. Pseudoexfoliative glaucoma is known to be the most aggressive and difficult-to-treat form of secondary glaucoma. According to the literature, pseudoexfoliative glaucoma occurs in 25-30% of cases among all open-angle glaucoma. The recent studies have established that a quarter of patients with pseudoexfoliative glaucoma are blind in one eye, and 7% are blind in both eyes. Risk factors for glaucoma include systemic and ophthalmic factors, one of which is the development of pseudoexfoliative syndrome. In patients with pseudoexfoliative syndrome, glaucoma occurs 20 times more often than in the general population of the same age. The purpose of this research is to study the informativeness of individual phenomena of pseudoexfoliative syndrome (PES) in order to improve early diagnosis and prevention of pseudoexfoliative glaucoma. The study included 114 patients diagnosed as having PES. Exclusion criteria were as follows: age up to 45 years, surgery on the eyeball, a history of disease (iridocyclitis, uveitis, corneal pathology, and traumatic eye disease), pigment dispersion syndrome. Along with the standard set of diagnostic measures, patients underwent biomicroscopy in the conditions of maximum drug-induced mydriasis, gonioscopic examination; the proportion of patients was examined by optical coherence tomography (SD-OCT Topson 3D oct-2000FA Plus (version 7/21/003/0)). The study revealed signs of pseudoexfoliative syndrome (deposition of pseudoexfoliative material on various structures of the anterior segment of the eye) in 100% of cases. Higher values of intraocular pressure (from 29 to 34 mm Hg) were found in the patients with elements of blocking the angle of the anterior chamber (narrowing or closing the angle, increased pigmentation and the presence of draining exfoliative conglomerates). The optical coherence tomography study revealed a thinning of the retinal nerve fibres (33.60 ± 0.43 μm), a significant thinning of retinal nerve fibre layer in patients with pseudoexfoliative syndrome and even more significant thinning in 29 patients diagnosed with pseudoexfoliative glaucoma. Thus, we can conclude knowing the microsymptoms of the disease, mandatory investigating the conditions of the maximum drug-induced mydriasis can contribute to detect pseudoexfoliative syndrome even in the initial stages and thus to prevent the development of pseudoexfoliative glaucoma.


2018 ◽  
Vol 59 (3) ◽  
pp. 1206 ◽  
Author(s):  
Xin Wei ◽  
Shozo Sonoda ◽  
Chitaranjan Mishra ◽  
Neha Khandelwal ◽  
Ramasamy Kim ◽  
...  

2007 ◽  
Vol 177 (4S) ◽  
pp. 358-359 ◽  
Author(s):  
Christopher S. Lee ◽  
Alek Mishail ◽  
Jason M. Kim ◽  
Alexander Kirshenbaum ◽  
Howard L. Adler ◽  
...  

2006 ◽  
Vol 175 (4S) ◽  
pp. 395-395
Author(s):  
Nancy J. Tresser ◽  
Elena V. Zagaynova ◽  
Olga S. Streltsova ◽  
Natalia D. Gladkova ◽  
Vladislav A. Kamensky ◽  
...  

2004 ◽  
Vol 171 (4S) ◽  
pp. 68-68 ◽  
Author(s):  
Markus D. Sachs ◽  
Dmitry Daniltchenko ◽  
Eva Lankenau ◽  
Frank Koenig ◽  
Gerion Huettmann ◽  
...  

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