scholarly journals Locating the optic nerve in a retinal image using the fuzzy convergence of the blood vessels

2003 ◽  
Vol 22 (8) ◽  
pp. 951-958 ◽  
Author(s):  
A. Hoover ◽  
M. Goldbaum
Keyword(s):  
Optic Nerve ◽  
Blood Vessels ◽  
Retinal Image ◽  
Fuzzy Convergence

scholarly journals Reliability of Manual Vascular Segmentation for Retinal Fractal Dimension using Peek Retinatm

2019 ◽  
Vol 8 (9S3) ◽  
pp. 1560-1564
Keyword(s):  
Fractal Dimension ◽  
Blood Vessel ◽  
Blood Vessels ◽  
Retinal Image ◽  
Retinal Images ◽  
Retinal Vasculature ◽  
Manual Segmentation ◽  
Good Reliability ◽  
Fundus Camera ◽  
Df Analysis

Fractal dimension (Df) has been identified as indirect measure in quantifying the complexity of retinal vessel network which is useful for early detection of vascular changes. Reliability studies of Df measurement on retinal vasculature, has been conducted on retinal images processed by using semi-automated software which only permits image with 45ᵒ field of view (FOV). Smartphone-assisted fundus camera retinal image has a maximum 30ᵒ FOV which warrant manual processing in measuring the Df. Retinal blood vessels need to be manually segmented to produce binary images for retinal vasculatures Df measurement. Therefore, this study was conducted to determine the intragrader and intergrader reliability of manual segmentation of the retinal vasculature Df measurement from retinal images taken using a smartphone-assisted fundus camera Forty-five retinal images were captured using the Portable Eye Examination Kit Retina (Peek Retina™, Peek Vision Ltd, UK). Suitable image for Df analysis were selected based on gradable retinal image criteria which included; i) good image focus, ii) centered position of optic nerve head (ONH) and iii) significant blood vessel visibility. The images were cropped 0.5 disc diameters away from disc margin and resized to 500x500 pixels using GNU Image Manipulation Program Version 2.8.18 (GIMP, The GIMP Team, United States). Retinal vessels were manually traced by using layering capabilities for blood vessel segmentation. Df values of segmented blood vessels were measured by using Image J (National Institutes of Health, USA) and its plugin software, FracLac Version 2.5. Intragrader and intergrader reliability was determined by comparing the Df values between; two readings measured one week apart by a grader and readings from two different graders, respectively, using intraclass correlation coefficient (ICC) and Bland-Altman graphical plots. Intragrader agreement for retinal Df showed good reliability with ICC of 0.899 (95% CI: 0.814–0.945). Bland Altman analysis indicated good agreement between Df values at different grading time (mean difference 0.0050; 95% CI:-0.0001–0.0101). Intergrader reliability for retinal Df was high with ICC of 0.814 (95% CI: 0.459–0.919). Bland Altman plot revealed good intergrader agreement for retinal Df between two graders with a bias value of 0.0158 (95% CI: 0.0092–0.0223). In conclusion, manual segmentation of retinal image captured by smartphone-assisted fundus camera has good reliability (0.75 < ICC < 0.9) for Df analysis to study the morphology of retinal vasculatures.

scholarly journals Retinal Image Graph-Cut Segmentation Algorithm Using Multiscale Hessian-Enhancement-Based Nonlocal Mean Filter

2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Jian Zheng ◽  
Pei-Rong Lu ◽  
Dehui Xiang ◽  
Ya-Kang Dai ◽  
Zhao-Bang Liu ◽  
...  
Keyword(s):  
Blood Vessels ◽  
Retinal Image ◽  
Symmetry Transformation ◽  
Graph Cut ◽  
Experimental Results ◽  
New Method ◽  
Retinal Vessels ◽  
Radial Gradient ◽  
Mean Filter ◽  
Graph Cut Segmentation

We propose a new method to enhance and extract the retinal vessels. First, we employ a multiscale Hessian-based filter to compute the maximum response of vessel likeness function for each pixel. By this step, blood vessels of different widths are significantly enhanced. Then, we adopt a nonlocal mean filter to suppress the noise of enhanced image and maintain the vessel information at the same time. After that, a radial gradient symmetry transformation is adopted to suppress the nonvessel structures. Finally, an accurate graph-cut segmentation step is performed using the result of previous symmetry transformation as an initial. We test the proposed approach on the publicly available databases: DRIVE. The experimental results show that our method is quite effective.

3-D segmentation of retinal blood vessels in spectral-domain OCT volumes of the optic nerve head

2010 ◽  
Author(s):  
Kyungmoo Lee ◽  
Michael D. Abràmoff ◽  
Meindert Niemeijer ◽  
Mona K. Garvin ◽  
Milan Sonka
Keyword(s):  
Optic Nerve ◽  
Blood Vessels ◽  
Optic Nerve Head ◽  
Spectral Domain ◽  
Spectral Domain Oct ◽  
Retinal Blood Vessels

scholarly journals Extraction of Blood Vessels from Retinal Image using Adaptive Morphology

2017 ◽  
Vol 168 (11) ◽  
pp. 28-34
Author(s):  
Rajat Suvra ◽  
Rohit Kamal ◽  
Avijit Kar
Keyword(s):  
Blood Vessels ◽  
Retinal Image ◽  
Adaptive Morphology

scholarly journals Optic nerve and retinal damage in a patient with post-hemorrhagic anemia

2015 ◽  
Vol 96 (6) ◽  
pp. 1074-1078
Author(s):  
E E Grishina ◽  
A A Ryabtseva ◽  
T V Belova ◽  
O M Andryukhina
Keyword(s):  
Visual Acuity ◽  
Optic Nerve ◽  
Iron Deficiency ◽  
Gastrointestinal Bleeding ◽  
Blood Vessels ◽  
Clinical Examination ◽  
Hemoglobin Level ◽  
Retinal Damage ◽  
Field Of Vision ◽  
The Right

There is a number of literature data on ischemic optic neuropathy development in acute hemorrhage. However, ocular disorders in prolonged chronic hemorrhage and iron-deficiency anemia are not well studied. We present a clinical case of optic nerve and retinal damage in a patient with prolonged chronic gastrointestinal bleeding. 53-year-old patient S. presented with complaints on dramatic sudden loss of vision of his right eye (visual acuity was 0/02 and was not improving with correction). Visual acuity of the left eye was good. Ophthalmoscopy revealed right optic nerve swelling, flame-shaped disc and peripapillary hemorrhages, and multiple soft exudates along blood vessels of the right eye. Optic nerve head of the left eye was pale pink, with well-defined borders. Multiple soft exudates along blood vessels and few flame-shaped hemorrhages were identified as well. Clinical examination revealed iron-deficiency post-hemorrhagic anemia. The diagnosis of anterior ischemic neuropathy of the right eye, ischemic neuroretinopathy of left eye associated with post-hemorrhagic anemia was established. Conservative treatment increased hemoglobin level up to 82 g/l, the red blood cells count - up to 2,88×1012/L, hematocrit was 0.25%, platelet count reached 344×109/L, but the signs of rectal bleeding remained. The patient underwent surgery for hemorrhoids. After the increase of hemoglobin level, visual acuity of the right eye improved to 0.1, the visual acuity of the left eye was 1.0. According to the results of computed peripheral vision test (Humphrey Full Field 120 Point Screening Test), central scotoma and scotomas in the lower half of the field of vision of the right eye remained. In the field of vision of the left eye, the area of absolute arcuate scotoma in the lower-nasal quadrant decreased significantly. Reduced visual acuity was the main complaint of the patient with a longstanding gastrointestinal bleeding. A careful history and thorough clinical examination allowed to establish the cause of the optic nerve and retinal damage, to assign pathogenetically based treatment, which led to an improvement in visual function.

Several observations on the therapeutic effect of arlyl nitrite in retinal pigment degeneration

1935 ◽  
Vol 31 (10) ◽  
pp. 1188-1194
Author(s):  
V. I. Grigoriev ◽  
L. A. Dymschitz
Keyword(s):  
Optic Nerve ◽  
Blood Vessels ◽  
Therapeutic Effect ◽  
Blood Supply ◽  
Retinal Pigment ◽  
Retinal Blood Vessels

Pigmented regeneration of the retina is one of those diseases of the eye's light-receiving apparatus, where the fact of poor blood supply to the retina and the optic nerve is striking. This is manifested by the more or less sharp contraction of retinal blood vessels visible in the ophthalmoscope.

Permeability of blood vessels and connective tissue sheaths in retina and optic nerve

1973 ◽  
Vol 26 (2) ◽  
pp. 147-156 ◽  
Author(s):  
Yngve Olsson ◽  
Krister Kristensson
Keyword(s):  
Optic Nerve ◽  
Connective Tissue ◽  
Blood Vessels

scholarly journals Note on the blood-vessel-system of the retina of the hedgehog (being a fourth contribution to the anatomy of the retina)

1869 ◽  
Vol 17 ◽  
pp. 357-358
Keyword(s):  
Optic Nerve ◽  
Blood Vessel ◽  
Blood Vessels ◽  
Lamina Cribrosa ◽  
Variable Number ◽  
Deep Pit ◽  
Retinal Blood Vessels ◽  
Membrana Limitans Interna ◽  
Inner Surface ◽  
Arteries And Veins

The distribution of the retinal blood-vessels in this common British Insectivore is so remarkable that I deem it worthy of a separate notice— only capillaries enter the retina . The vasa centralia pierce the optic nerve in the sclerotic canal, and, passing forwards through the lamina cribrosa, divide, at the bottom of a relatively large and deep pit in the centre of the intraocular disk of the nerve, into a variable number of primary branches, from three to six. These primary divisions quickly subdivide, furnishing many large arteries and veins, which, radiating on all sides from the nerve-entrance towards the ora retinæ, appear to the observer’s unaided eye as strongly projecting ridges upon the inner surface of the retina. When vertical sections parallel to and across the direction of these ridges are examined with a quarter-inch objective, we immediately perceive that the arteries and veins lie, throughout their entire course, upon the inner surface of the membrana limitans interna retinæ, between this and the membrana hyaloidea of the vitreous humour, and that only capillaries penetrate the retina itself.

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