Eye on a Dish Models to Evaluate Splicing Modulation.

Inherited retinal dystrophies, such as Leber congenital amaurosis, Stargardt disease, and retinitis pigmentosa, are characterized by photoreceptor dysfunction and death and currently have few treatment options. Recent technological advances in induced pluripotent stem cell (iPSC) technology and differentiation methods mean that human photoreceptors can now be studied in vitro. For example, retinal organoids provide a platform to study the development of the human retina and mechanisms of diseases in the dish, as well as being a potential source for cell transplantation. Here, we describe differentiation protocols for 3D cultures that produce retinal organoids containing photoreceptors with rudimentary outer segments. These protocols can be used as a model to understand retinal disease mechanisms and test potential therapies, including antisense oligonucleotides (AONs) to alter gene expression or RNA processing. This "retina in a dish" model is well suited for use with AONs, as the organoids recapitulate patient mutations in the correct genomic and cellular context, to test potential efficacy and examine off-target effects on the translational path to the clinic.