University of California, Irvine (UCI) scientists have created an eight-layer, early-stage retina from human embryonic stem cells, the first three-dimensional tissue structure to be made from stem cells.

It also marks the first step toward the development of transplant-ready retinas to treat eye disorders such as retinitis pigmentosa and macular degeneration that affect millions.

The team utilized stem cell differentiation to create the multiple cell types necessary for the retina. However, the greatest challenge, said study leader Hans Keirstead, was in the engineering. To mimic early-stage retinal development, the researchers needed to build microscopic gradients for solutions in which to bathe the stem cells to initiate specific differentiation paths.

The UCI researchers are testing the early-stage retinas in animal models to learn how much they improve vision. Positive results would lead to human clinical trials.

The study appears online in the Journal of Neuroscience Methods.