With the support of Vision of Children, Dr. Karl Wahlin of the Shiley Eye Institute at UC San Diego is leading a project that hopes to reverse blindness caused by a variety of inherited retinal disorders, including Ocular Albinism type 1 (OA1). Their approach aims to tap into a cellular blueprint that enables many species, including fish and amphibians, to repair damaged retinas. While this process does not readily occur in humans, Wahlin and colleagues believe that it is entirely possible that this repair process can be activated in humans too.

Much like a light switch, Wahlin and colleagues have developed a genetic switch that activates or turns “on” genes simply by adding a harmless drug to the eye. During human eye development, cells form by the selective expression of master regulator genes which serve as instructions for determining which types of cells will form. The gene switches developed at UC San Diego were used to successfully reprogram induced pluripotent stem cells (iPSCs) into new neurons, including light sensitive photoreceptor cells. This occurred at high efficiency and at a pace that is far faster than anything they have seen before. Since individuals with OA1 have underdeveloped photoreceptors and other retinal disorders, such as retinitis pigmentosa, are lacking these cells altogether, the ability to generate new visual cells means that researchers are one step closer to generating new neurons in the human eye.

Taking their work to the next stage, the UC San Diego team has developed a means to grow miniature 3D human retinas that mimic many important aspects of the human eye, albeit at a much smaller scale. They are using these human mini-retinas to develop and test a gene therapy that would deliver genetic switches to the eye, generate new photoreceptors and eventually restore vision.