macula

The macula, from the Latin for spot, is a term used in anatomy to describe a small, flat region that differs from its surroundings. In ophthalmology, the macula lutea is a yellowish, oval area near the center of the retina, adjacent to the optic disc. It is about 5.5 mm in diameter; at its center lies the fovea centralis, a pit that provides the sharpest vision.

The macula contains a high density of cone photoreceptors and a specialized thinning of inner retinal layers at the fovea, enabling high-acuity, color vision. The retina contains macular pigment composed of the carotenoids lutein and zeaxanthin, which filter blue light and protect against photochemical damage.

Clinically, macular disease can cause central vision loss. Age-related macular degeneration (AMD) is the leading cause of blindness in older adults in developed countries; it can be dry or wet. Other macular conditions include diabetic macular edema, macular hole, and epiretinal membrane. Diagnosis commonly uses fundus examination and optical coherence tomography; treatment varies from anti-VEGF injections for neovascular AMD to laser therapy and nutritional supplements (AREDS2 formulation) for prevention.

In dermatology, a macule is a flat, circumscribed skin lesion whose color differs from surrounding skin. It is typically nonpalpable and less than 1 cm in diameter; a patch is its larger counterpart. Freckles and cafe-au-lait spots are examples of macules; vitiligo patches are depigmented macules.