Researchers have successfully crafted a functioning human retina using human stem cells. This lab-made retina is miniature compared to the real thing, but the researchers claim it can sense light much like its natural counter-parts, according to a recent study.
The study, published in Nature Communications, details how researchers from Johns Hopkins University have successfully created semi-functioning retinal tissue using induced pluripotent stem cells (iPS).
Unlike the highly controversial but extremely useful embryonic stem cells of old, iPS cells are somewhat new to the stem-cell research field (relatively speaking). Researchers are now able to create embryonic-like stem cells by genetically reprogramming specialized adult stem cells to revert back to all-purpose forms.
According to the study, researchers were able to take these iPS cells and stimulate them to turn into and produce retinal progenitor cells - cells designed to create the retinal tissue that lines the back of the human eye.
"We have basically created a miniature human retina in a dish that not only has the architectural organization of the retina but also has the ability to sense light," study leader M. Valeria Canto-Soler said in a recent statement.
The retinal tissue is the physiological equivalent of tissue that has developed for 28 weeks in the womb. Once they realized its capabilities, Canto-Soler and her team then tested the light sensitivity of the mini retinas by placing a single electrode into a photoreceptor cell. The team aimed a pulse of light at the cell and measured the tissue's reaction.
Amazingly, the photoreceptors responded to the light the same way natural retinal rods do.
Canto-Soler is quick to admit that while the retinal tissue reacts properly, it is just part of a greater process of vision that requires structures not yet successfully created in a lab.
"Is our lab retina capable of producing a visual signal that the brain can interpret into an image?" she said. "Probably not, but this is a good start."
According to Canto-Soler, these results could help advance "opportunities for vision-saving research and may ultimately lead to technologies that restore vision in people with retinal diseases."
The study was published in Nature Communications on June 10.