[Avascular retinal pigment epithelium detachments in age-related macular degeneration]

Retinal pigment epithelium detachment (PED) is a pathological condition in which retinal pigment epithelium is separated from the underlying Bruch's membrane due to the formation of a fibrovascular membrane, drusenoid material, accumulation of fluid and/or blood. Six types of RPE detachments have been determined: pseudovitelliform, detachments associated with drainage drusen, serous, vascular and hemorrhagic, as well as PED associated with vascular retinal anomaly. The drusenoid PED is always avascular, the drusenoid material is contained between the RPE and Bruch's membrane. It was first described by Casswell in 1985. Ophthalmoscopy of the fundus shows a yellow-white cellular structure in the subretinal space, sometimes containing a patch of pigment, with an uneven surface, clear boundaries and a wavy edge. Serous PED is larger in area and prominence than drusenoid, characterized by the presence of a hyporeflective area under the detached RPE, over the area of more than 50% of the total area of detachment. Ophthalmoscopy shows a transparent yellow lesion in the subretinal space, sometimes brown-tinted, with clear boundaries and dome-shaped prominence. True serous PED is avascular (combination of choroidal neovascularization and serous PED will be discussed in the article about vascularized PED).