The macula or macula lutea (from Latin macula, "spot" + lutea, "yellow") is an oval-shaped pigmented area near the centre of the retina of the human eye and some other animalian eyes. 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 (FAZ), fovea, parafovea, and perifovea areas.[1] After death or enucleation (removal of the eye) the macula appears yellow, a color that is not visible in the living eye except when viewed with light from which red has been filtered. The anatomical macula at 5.5 mm (0.22 in) is much larger than the clinical macula which, at 1.5 mm (0.059 in), corresponds to the anatomical fovea. The clinical macula is seen when viewed from the pupil, as in ophthalmoscopy or retinal photography. The anatomical macula is defined histologically in terms of having two or more layers of ganglion cells.[6] The umbo is the centre of the foveola which in turn is located at the centre of the fovea.
The fovea is located near the centre of the macula. It…show more content… Inflammatory processes and an increase in vascular permeability play a central role. The macula is the part of the retina responsible for sharp, central vision due to its high density of cone photoreceptors. It is situated at the back of the retina (the posterior pole), lying about 3 mm lateral to the optic disc. It has a central depression known as the fovea centralis. The fovea contains tightly packed cone photoreceptors in the fovea with no overlying blood vessels. This is the area of the retina where visual acuity is ultimately determined, where reading takes place and where form, shape and colour are most accurately detected. Macular fluid accumulation alters cell function in the retina as well as provoking an inflammatory reparative
