How Are Stressors Causing AMD?

What: Study results show a causative role of environmental factors, including iron overload and cigarette smoke, in age-related macular degeneration (AMD).

Where: “Environmental Stress Impairs Photoreceptor Outer Segment (POS) Phagocytosis and Degradation and Induces Autofluorescent Material Accumulation in HiPSC-RPE Cells,” Cell Death Discovery, 2019

BrightFocus Connection: Senior author Ruchira Singh, PhD, of the University of Rochester, received a grant for this work from BrightFocus Foundation’s Macular Degeneration Research program.

Why It Is Important: Photoreceptor outer segments (POS) are a part of the light-sensing neurons of the eye that are shed daily and removed by the RPE cells. Accumulation of partially digested autofluorescent POS materials in the RPE then becomes part of toxic debris that contributes to the development of AMD. Environmental factors, such as excess iron in the eye and cigarette smoke, have long been linked with AMD.  The authors make an even clearer connection, showing it can impair the retina’s ability to dispose of POS and lead to autofluorescent material accumulation in RPE cells.  The work provides evidence of the direct role that iron overload and cigarette smoke have on cell dysfunction in AMD and possibly other retinal degenerative diseases.