We present a new method for the quantitative estimation of blood flow velocity, based on the use of the Radon transform. The specific application is for measurement of blood flow velocity in the retina. Our modified fundus camera uses illumination from a green LED and captures imagery with a high-speed CCD camera. The basic theory is presented, and typical results are shown for an in vitro flow model using blood in a capillary tube. Subsequently, representative results are shown for representative fundus imagery. This approach provides absolute velocity and flow direction along the vessel centerline or any lateral displacement therefrom. We also provide an error analysis allowing estimation of confidence intervals for the estimated velocity.
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http://dx.doi.org/10.1117/1.3494565 | DOI Listing |
Heliyon
July 2024
D-Eye Srl, Padova, 35131, Italy.
Widespread screening is crucial for the early diagnosis and treatment of glaucoma, the leading cause of visual impairment and blindness. The development of portable technologies, such as smartphone-based ophthalmoscopes, able to image the optical nerve head, represents a resource for large-scale glaucoma screening. Indeed, they consist of an optical device attached to a common smartphone, making the overall device cheap and easy to use.
View Article and Find Full Text PDFNPJ Digit Med
January 2025
Joint Shantou International Eye Center, Shantou University and the Chinese University of Hong Kong, Shantou, Guangdong, 515041, China.
Label noise is a common and important issue that would affect the model's performance in artificial intelligence. This study assessed the effectiveness and potential risks of automated label cleaning using an open-source framework, Cleanlab, in multi-category datasets of fundus photography and optical coherence tomography, with intentionally introduced label noise ranging from 0 to 70%. After six cycles of automatic cleaning, significant improvements are achieved in label accuracies (3.
View Article and Find Full Text PDFInt Ophthalmol
December 2024
School of Computer Science, UPES, Dehradun, India.
Background: Diabetic Retinopathy (DR) is a leading cause of blindness among individuals aged 18 to 65 with diabetes, affecting 35-60% of this population, according to the International Diabetes Federation. Early diagnosis is critical for preventing vision loss, yet processing raw fundus images using machine learning faces significant challenges, particularly in accurately identifying microaneurysm lesions, which are crucial for diagnosis.
Methods: This study proposes a novel pre-processing technique utilizing the Modified Fuzzy C-means Clustering approach combined with a Support Vector Machine classifier.
Cardiovasc Intervent Radiol
January 2025
Department of Gastroenterology and Hepatology, Zhongnan Hospital of Wuhan University, No. 169, Donghu Road, Wuchang District, Wuhan, 430071, Hubei Province, China.
Purpose: This study aimed to explore a modified direct intrahepatic portocaval shunt (DIPS) technique as an alternative approach for patients with portal vein occlusion (PVO) and cirrhosis who were not candidates for traditional transjugular intrahepatic portosystemic shunt (TIPS) due to anatomical challenges.
Technique: Three patients with esophageal or gastric fundus variceal hemorrhage complicated by severe PVO were treated using innovative DIPS approaches. Preoperative contrast-enhanced computed tomography was employed to assess anatomical feasibility.
Medicine (Baltimore)
December 2024
Department of Ophthalmology, Adana City Training and Research Hospital, Adana, Türkiye.
This study aimed to evaluate the presence and comparison of microvascular abnormalities in essential tremor (ET) and Parkinson disease (PD) using optical coherence tomography angiography (OCT-A) and to show the relationship between retinal microvascular changes and disease stage in the patient group. A total of 176 eyes, including 26 PD diagnosed according to the United Kingdom PD Society Brain Bank criteria, 31 ET diagnosed according to the Washington heights-inwood genetic study of ET (WHIGET) criteria and 31 healthy controls, were included in the study. Unified PD assessment scale (UPDRS) motor scores, non-motor symptom scale (NMS), modified Hoehn&Yahr stages (mH&Y) and Fahn-Toloso-Marin grading scale were recorded.
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