Macular dystrophies, including age-related macular degeneration, are a group of eye disorders characterized by loss of central vision and the presence of drusen, which are lipid-rich deposits in the retina.

Although a number of such disorders share key features and follow similar trajectories, their underlying mechanisms remain unknown, partly due to the lack of a suitable animal model. Researchers used human induced pluripotent stem cell-derived retinal pigment epithelium (hiPSC-RPE) to examine the specific role of RPE dysfunction in two features of macular dystrophy: accumulation of extracellular matrix protein and formation of drusen.

Working with 11 different hiPSC-RPE lines, including cells derived from patients with three distinct macular dystrophies, the authors developed models and demonstrated that RPE dysfunction is sufficient to recapitulate the hallmark features of these conditions.

Furthermore, the results reveal that similar molecular alterations are present in RPE cells derived from patients with distinct maculopathies, suggesting that the disorders manifest through shared mechanisms.

The study demonstrates the utility of hiPSC-RPE as a model system and provides insights into the role of RPE cell dysfunction in this group of eye disorders, according to the authors. 

http://www.pnas.org/content/early/2017/09/01/1710430114