Centrifugal Fundus Abnormalities in Pseudoxanthoma Elasticum

Abstract

To investigate the Bruch's membrane-retinal pigment epithelium (RPE) complex in pseudoxanthoma elasticum (PXE) by imaging techniques capable of visualizing deep retinal structures with high contrast. Prospective cross-sectional study. Patients with PXE, confirmed by mutation analysis, skin histopathologic examination, or both. Sixteen patients were investigated by indocyanine green (ICG) and fluorescein angiography, confocal near-infrared (NIR) reflectance, and fundus autofluorescence imaging using a confocal scanning laser ophthalmoscope (Spectralis HRA-OCT; Heidelberg Engineering, Heidelberg, Germany). Composite digital fundus photography also was performed. Characterization and topographic distribution of abnormalities detected by retinal imaging. On late-phase ICG angiography, a central area of decreased fluorescence centered on the posterior pole was a characteristic finding in all patients. A second area characterized by increased fundus reflectivity on NIR reflectance imaging extended further into the periphery. A third and most eccentric area showed neither decreased ICG fluorescence nor increased fundus reflectivity. These 3 areas were separated by 2 transition zones, the second being the equivalent of peau d'orange. Angioid streaks did not extend into the third area. The abnormalities detected by this multimodal imaging approach suggest a centrifugal spread of the retinal pathologic features of the Bruch's membrane-RPE complex in PXE. Decreased fluorescence on late-phase ICG angiography is a consistent sign of retinal pathologic features in PXE. Bruch's membrane calcification may be the underlying cause for the increased reflectivity observed on NIR reflectance imaging. Proprietary or commercial disclosure may be found after the references.