Evidence for vasculitis in acute posterior multifocal placoid pigment epitheliopathy.

A case of acute posterior multifocal placoid pigment epitheliopathy is presented with the unusual feature of the exposure of deep choroidal vessels which filled with dye in the early phase of the fluorescein angiogram in the center of many of the placoid lesions. Visualization of these vessels with surrounding hypofluorescence implies nonperfusion of choriocapillaris presumably due to inflammation, rather than retinal pigment epithelial blockage. The pathology of acute posterior multifocal placoid pigment epitheliopathy is probably a vasculitis of the choriocapillaries, which causes transient occlusion of these vessels and the initial hypofluorescence in the typical lesions during angiography. In many lesions the ischemia is mild enough to cause only temporary disturbance of visual function with subsequent recovery. Only in the center of some of the lesions is the inflammation severe enough to allow for the findings observed in the case presented and to account for the permanent visual defects found in some patients.