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Applying Digital Processing Methods in the Analysis of Retinal Structure
Published in Rangachar Kasturi, Mohan M. Trivedi, Image Analysis Applications, 2020
Sunanda Mitra, Thomas F. Krile
Macular degeneration is another retinal disease (Gass/1977) that causes loss of fine vision, although peripheral vision remains intact in this case. Conventional image-enhancement techniques improve the quality of fundus images for better evaluation and classification of a particular group of macular diseases—namely, macular holes (Mitra et al./1986). The diagnosis of macular hole refers to either a full thickness or a partial thickness (lamellar) hole in the macular area. The most commonly occurring full-thickness macular hole is of unknown cause, although a number of factors, such as myopic degeneration, contraction of an epiretinal membrane, trauma, and solar retinopathy, have been implicated as etiologic factors in some cases (Gass/1977, Maumenee/1967). Differential classification of macular holes, macular cysts, and pseudomacular holes (hole-like appearance due to contraction in the epiretinal membrane) is not always readily available (Gass/1975). Fluorescein angiography may be of some help in differential diagnosis of macular holes from pseudomacular holes (Allen and Gass/1978).
Detection of macular diseases in optical coherence tomography image
Published in International Journal of Parallel, Emergent and Distributed Systems, 2020
Xiaoming Liu, Zhou Yang, Wei Hu, Jun Liu, Kai Zhang
Many macular diseases can lead to vision decreasing or blindness such as macular edema, macular hole and age-related macular degeneration (shown in Figure 2). Macular edema [3] occurs when fluid and protein deposit on the macular and cause retina to thicken or swell. It can be classified into cystoid macular edema involving fluid accumulation in the outer plexiform layer, and diabetic macular edema caused by leaking macular capillaries. Macular hole [4] is a small break in the macular. The vitreous is a jelly-like substance in the eye, and it is usually adherent to retina. Along with the growth of age, vitreous get watery and begin to separate from the retinal surface. The higher the degree of attachment between vitreous and retina, the more likely macular hole is developed. Age-related macular degeneration [5] typically occurs in older people where the severity is divided into early, intermediate and late types. Drusen, which appear as a bulge, is an important clinical indicator for this disease, and it occurs at the neighbourhood of retinal pigment epithelium (RPE).