The Natural History of Bruch’s Membrane Calcification in Pseudoxanthoma Elasticum

Purpose To describe the natural history of Bruch's membrane (BM) calcification in patients with pseudoxanthoma elasticum (PXE).Design Retrospective cohort study.Participants Both eyes of 120 PXE patients younger than 50 years, 78 of whom had follow-up imaging after more than 1 year.Methods All patients underwent multimodal imaging, including color fundus photography, near-infrared reflectance (NIR) imaging, and late phase indocyanine green angiography (ICGA). We determined the distance from the optic disc to the central and temporal border of peau d'orange on NIR, expressed in horizontal optic disc diameter (ODD). The length of the longest angioid streak was classified into 5 zones.Main outcome measures Age-specific changes of peau d'orange, angioid streaks, and ICGA hypofluorescence as surrogate markers for the extent of BM calcification.Results In cross-sectional analysis, longer angioid streaks were associated with increasing age (P P P = 0.69). New or growing angioid streaks were detected in 39 of 156 eyes (25%). The hypofluorescent area on ICGA was visible only in the fourth or fifth decade and correlated with longer angioid streaks.Conclusions In PXE patients, the speckled BM calcification slowly confluences during life. The location of the temporal border of peau d'orange remains rather constant, whereas the central border shifts to the periphery. This suggests the presence of a predetermined area for BM calcification. A larger ICGA hypofluorescent area correlates with older age and longer angioid streaks, which implies that it depends on the degree of BM calcification.