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The macula (/ˈmakjʊlə/) [1] or macula lutea is an oval-shaped pigmented area in the center of the retina of the human eye and in other animals. The macula in humans has a diameter of around 5.5 mm (0.22 in) and is subdivided into the umbo , foveola , foveal avascular zone , fovea , parafovea , and perifovea areas.
Photograph of the retina of the human eye, with overlay diagrams showing the positions and sizes of the macula, fovea, and optic disc. Perifovea is a region in the retina that circumscribes the parafovea and fovea and is a part of the macula lutea. [1] The perifovea is a belt that covers a 10° radius around the fovea and is 1.5 mm wide.
The area of the macula constitutes only about 2.1% of the retina, and the remaining 97.9% (the peripheral field) remains unaffected by the disease. Even though the macula provides such a small fraction of the visual field, almost half of the visual cortex is devoted to processing macular information. [14]
Recently, central serous chorioretinopathy has been understood to be part of the pachychoroid spectrum. [5] [6] In pachychoroid spectrum disorders, of which CSR represents stage II, the choroid, the highly vascularized layer below the retina, is thickened and congested with increased blood vessel diameter, especially in the deep choroid (the so-called Haller's layer).
The fovea centralis is a small, central pit composed of closely packed cones in the eye.It is located in the center of the macula lutea of the retina. [1] [2]The fovea is responsible for sharp central vision (also called foveal vision), which is necessary in humans for activities for which visual detail is of primary importance, such as reading and driving.
Parafovea or the parafoveal belt is a region in the retina that circumscribes the fovea and is part of the macula lutea. [1] It is circumscribed by the perifovea.. Photograph of the retina of the human eye, with overlay diagrams showing the positions and sizes of the macula, fovea, and optic disc
Diagram of the human eye showing macula and fovea. Although J. D. Gass originally identified four types of idiopathic juxtafoveolar retinal telangiectasis in 1982, contemporary researchers describe three types collectively known as idiopathic juxtafoveal telangiectasia: macular telangiectasia type 1, macular telangiectasia type 2, and macular telangiectasia type 3.
The elements composing the layer of rods and cones (Jacob's membrane) in the retina of the eye are of two kinds, rod cells and cone cells, the former being much more numerous than the latter except in the macula lutea. Jacob's membrane is named after Irish ophthalmologist Arthur Jacob, who was the first to describe this nervous layer of the ...