New Discovery of Vitamin A Changes Scientists' Understanding of Vision

Researchers at Johns Hopkins University have identified the developmental mechanism underlying the emergence of sharp central vision in humans before birth, after pinpointing a precisely timed interaction between a vitamin A-derived molecule and thyroid hormones within the retina. This discovery challenges a scientific explanation that has been dominant for decades regarding how the primary light-sensing cells are formed, and it may pave the way for developing future treatments for vision-threatening conditions such as macular degeneration, glaucoma, and other retinal disorders.

Robert Johnston, an associate professor of biology at Johns Hopkins University who led the study, described this mechanism as “a crucial step toward understanding the internal mechanisms of the retinal center, a vital part of the eye that is the first to be affected in individuals with macular degeneration.” By gaining a better understanding of this region and developing organoid models that mimic its function, scientists hope that one day they will be able to grow and transplant these tissues to restore vision.

To investigate how the human eye develops, the researchers used organoids—small clusters of tissue grown from embryonic cells that accurately mimic parts of the retina. After monitoring these lab-grown retinas over several months, the research team identified the cellular processes that form the fovea, the small central area of the retina responsible for the sharpest vision, according to Science Daily, citing the journal Proceedings of the National Academy of Sciences.