Vision is made possible by photoreceptors, the light-sensitive cells of the retina in the back of the eye. There are hundreds of blinding genetic conditions that are caused by problems with photoreceptors. Many mechanisms of genetic retinal diseases and how they impact photoreceptors have not been fully understood. Currently there are limited treatment options for people who suffer from these diseases.
Duke retina researchers led by Oleg Alekseev, MD, PhD, Assistant Professor of Ophthalmology, and Vadim Arshavsky, PhD, Distinguished Professor of Ophthalmology, discovered a unique structure in human photoreceptors that was previously unknown. This research was published on January 16 in Communications Biology, a Nature publication. Alekseev and colleagues have named this newly described photoreceptor structure the “accessory inner segment.”
Uncovering this novel structure opens new research possibilities to better understand the mechanisms of inherited retinal diseases and may ultimately lead to the development of innovative treatments for hereditary blindness.
“This intriguing discovery reveals that human photoreceptors are quite different from what was previously thought. It opens the door for further breakthroughs in our understanding of hereditary retinal diseases, which may ultimately lead to the development of medications for people with currently incurable blinding conditions,” said Alekseev, corresponding author of the study.
The research team obtained human donor eyes through Duke’s BioSight Tissue Repository and Service Center. They analyzed the human retinas using cutting-edge microscopy techniques, particularly 3-dimensional electron tomography. This allowed the researchers to visualize human photoreceptors at an unprecedented resolution and level of detail, facilitating their discovery of this new structure.
Co-authors include: Tylor R. Lewis, PhD; Natalia V. Klementieva, PhD; Sebastien Phan, PhD; Carson M. Castillo, MS; Keun-Young Kim, PhD; Lauren Y. Cao, BS; Mark H. Ellisman, PhD.