- Tiny yellow or white deposits in the retina of the eye or on the optic nerve head. The presence of drusen is one of the most common early signs of age-related macular degeneration (AMD. The eye care specialist can see drusen during an eye examination. Their presence alone does not indicate disease, but it may mean that the eye is at risk for developing more severe AMD.
* * *Small bright structures seen in the retina and in the optic disk. [Ger. pl. of Druse, stony nodule, geode]- basal laminar d. small, round, translucent lesions measuring 25–75 μm in diameter, which represent nodular thickening of the basement membrane of the retinal pigment epithelium, often with an overlying focal detachment of the retinal pigment epithelium from Bruch membrane. SYN: cuticular d..- basal linear d. deposits of long-spaced collagen located between the plasma membrane and basement membrane of the retinal pigment epithelium.- exudative d. accumulations of an amorphous and granular material, cytoplasmic processes, and bent fibers between the basement membrane of the retinal pigment epithelium and the inner collagenous zone of Bruch membrane; types of exudative d. include hard d. and soft d.. SYN: typical d..- hard d. type of exudative or typical d. that appear ophthalmoscopically as discrete, yellow nodules characterized histopathologically by well-defined accumulations of hyaline material in the inner and outer collagenous zones of Bruch membrane.- d. of the macula excrescences of Bruch membrane that produce a window in the retinal pigment epithelium and are a feature of age-related macular retinal degeneration. SYN: macular d..- d. of the optic nerve head basophilic, laminated, calcareous acellular masses that resemble crystals within the nerve head, anterior to the lamina cribrosa, that may simulate papilledema and/or cause visual field defects. SYN: intrapapillary d..- soft d. type of exudative d. that appear ophthalmoscopically as placoid, yellow lesions characterized histopathologically by localized serous detachments of the retinal pigment epithelium from the Bruch membrane.- typical d. SYN: exudative d..
* * *pl. n.1. (macular drusen) white or yellow deposits of hyalin in Bruch's membrane of the choroid. They are often associated with macular degeneration.2. (disc drusen) glistening nodules seen on an irregularly raised optic disc. Consisting of excess glia (produced congenitally) that has undergone degeneration and calcification, they can be confused with papilloedema.
* * *dru·sen (drooґzən) sing. druse [Ger. â€œbumpsâ€] 1. hyaline excrescences in the Bruch layer of the choroid; they usually result from aging, but sometimes occur with pathologic conditions. 2. sulfur granules.
Extensive small or cuticular drusen in a 56-year-old man.
Medical dictionary. 2011.