Current knowledge on reticular pseudodrusen in age-related macular degeneration

Drusen are focal deposits of extracellular material located between the retinal pigment epithelium (RPE) and Bruch's membrane and represent the major phenotypic characteristic of age-related macular degeneration (AMD). Due to evolving imaging techniques and recent histological studies, reticular pseudodrusen (RPD) have received increasing attention and have been recently identified as an additional phenotypic entity in AMD. In contrast to conventional drusen, RPD proved to be located internal to the RPE. In the past few years, numerous studies collected new findings on RPD related to their pathogenesis, imaging properties and impact on retinal function. While most former natural history studies as well as interventional studies in early AMD did not include imaging RPD beyond colour fundus photography, this phenotype must be included in every future large-scale study on AMD. This review summarises the current knowledge on RPD.