Reticular pseudodrusen associated with a diseased bruch membrane in pseudoxanthoma elasticum

Importance Reticular pseudodrusen (RPD) are frequently associated with age-related macular degeneration and considered to be an independent risk factor for disease progression, but the pathophysiologic mechanisms are only incompletely understood. Therefore, it may be helpful to identify the associations of RPD with other diseases that have defined pathophysiologic mechanisms. Objective To describe the phenotype, prevalence, and topographic distribution of RPD in patients with pseudoxanthoma elasticum (PXE) and their association with a diseased Bruch membrane. Design, Setting, and Participants In this single-center, prospective, cross-sectional case series, 57 consecutive patients with PXE from a university referral center whose diagnosis has been confirmed by genetic testing and/or skin biopsy were studied from March 1, 2013, through February 28, 2014. Main Outcomes and Measures Phenotypic characteristics of RPD were evaluated with multiple imaging techniques. The RPD were defined as irregular networks of round to oval lesions that appear hyporeflective on near-infrared reflectance, hypoautofluorescent on fundus autofluorescence, and as subretinal deposits on spectral-domain optical coherence tomographic images. The presence of RPD was judged based on characteristic findings in at least 2 of the 3 imaging modalities. Results A total of 57 patients were examined, and 15 patients were excluded mainly because of large central atrophy or fibrosis. In the remaining 42 patients with PXE, RPD were detected in 22 patients (52%; 95% CI, 38%-67%). Prevalence of RPD was highest in the fifth decade at 67% (10/15; 95% CI, 42%-85%). The RPD were most frequently located within the superior quadrant and least frequently located within the central macula. The RPD were always located central to areas with peau d’orange and within an area of hypofluorescence on late-phase indocyanine green angiographic images. Conclusions and Relevance These data suggest that RPD have a high prevalence in eyes of patients with PXE. Although RPD in patients with PXE occur at a younger age, their distribution and phenotype appear to be similar to RPD associated with age-related macular degeneration. The association with diseased Bruch membrane in PXE suggests a pathogenetic role of Bruch membrane alterations for the development of RPD.