Age-related retinal pigment epithelium disease (ARPED): clinical and differential features

Purpose: We described the clinical characteristics of age-related retinal pigment epithelium disease (ARPED). This looks like an age-related, retinal disease showing a primary retinal pigment epithelium (RPE) involvement, no typical age-related macular degeneration (AMD) features, and no pachychoroid-related characteristics. Methods: The study was designed as observational, both cross-sectional and retrospective investigation. We collected data from patients affected by ARPED, defined by precise diagnostic criteria. We performed both qualitative and quantitative multimodal retinal imaging investigations. The main outcome measure is the characterization of ARPED, defined by precise diagnostic criteria, with respect to AMD. Secondary outcome is the identification of differential diagnostic features with respect to other retinal diseases. Results: We included 31 ARPED eyes (62 patients). Inter-graders agreement for detecting ARPED was 0.98 (p<0.05). ARPED is characterized by the absence of AMD-related findings, such as drusen and pseudodrusen. Moreover, it is characterized by the absence of pachychoroid-related features, as also confirmed by fluorescein angiography and indocyanine green angiography. Conclusions: Although further studies are warranted to better define ARPED features and if it may be considered a distinct macular disease, the characteristics of this clinical phenotype introduce new intriguing pathophysiologic features and should be carefully considered both in clinical practice and research contexts.