University College London Great Ormond Street Institute of Child Health  (UCL GOS ICH) scientists have reportedly grown tiny human eyes that can help them understand a rare hereditary eye condition called Usher syndrome that causes blindness. In addition, the miniature eyes will help scientists understand blindness development and progression in Usher syndrome patients. 

Miniature eyes to help understand Usher syndrome 

The scientists created these 3D “mini eyes” called organoids using stem cells produced from skin samples donated by Greta Ormond Street Hospital for Children (GOSH) patients. 

Light-sensing rod cells can be found at the back of the eye in the retina of a healthy eye. In the latest study, researchers managed to provoke the rod cells and organize them in layers replicating how they would appear in the retina to create a tiny eye.

This field has advanced significantly with the development of these tiny eyes. The Usher syndrome, a common hereditary cause of blindness and deafness, has not previously been able to be replicated using cellular structure. Three to ten out of every 100,000 people are globally affected. Most Type 1 Usher syndrome patients are born profoundly deaf as infants, but their vision deteriorates considerably more slowly before blindness comes in around maturity.

Currently, retinitis pigmentosa, which is the main cause of vision loss related to Usher syndrome, doesn’t have any treatments. Although the latest findings are preliminary, they open ups new possibilities in understanding the condition and creating effective treatments that could help many retain their eyesight. 

Muller cells responsible for the development of Usher syndrome 

The miniature eyes will help researchers evaluate light-detecting cells from an eye at an individual level. Most importantly, thanks to single-cell RNA sequencing, it is the first time researchers have used miniature molecular changes in rod cells before death. 

Interestingly, the researchers found that Muller cells are involved in Usher syndrome. Usually, Muller cells are important in the retina’s structural and metabolic support. However, in usher syndrome people’s cells abnormally showed genes turned on for protein breakdown and stress responses. Therefore, reversing these developments could be important in stopping disease progression.