Researchers grow ‘mini eyes’ in a laboratory to assess blindness in a breakthrough study

Researchers have grown ‘mini eyes’ in a lab so that they can study blindness in a rare genetic condition called Usher Syndrome.

For the first time ever, researchers created the 3D ‘mini eyes’, also called retinal organoids. They were grown from stem cells generated from skin samples donated by patients at Great Ormond Street Hospital for Children (GOSH).

The results from the study were published in the journal Stem Cell Reports.

Organizing the rod cells to imitate structure in the retina

The researchers from University College London Great Ormond Street Institute of Child Health (UCL GOS ICH) in the U.K. discovered that they could get rod cells to organize themselves into layers that imitate their structure in the retina. Normally, in a healthy eye, these rod cells are arranged in the back of the eye in a region that is known for processing images.

The 'mini eyes' are a significant step forward in the right direction because prior research used animal cells, which couldn’t simulate the same level of sight loss observed within Usher Syndrome.  

What is Usher Syndrome?

Usher syndrome is the most common genetic cause of both sight loss and hearing loss. It can also cause an eye disease called retinitis pigmentosa, which affects the retina and causes progressive vision loss. The condition affects approximately three to ten in 100,000 people globally. Children with the specific Type 1 Usher syndrome are often born deaf, while their sight deteriorates into their adulthood.

Although individuals can wear cochlear implants to help with deafness, there are no current treatments for blindness in Usher syndrome, or retinitis pigmentosa. Although the research is in its preliminary stages, it is useful in possibly helping people with the disease, providing hope and optimism for a potential breakthrough treatment.

Viewing molecular changes in rod cells

The ‘mini eyes’ created allow researchers to study light-sensing cells from the human eye individualistically.  This also allows the team to study the cells in more detail.

It was the first-time researchers could view the molecular changes in the rod cells before they died. This was due to the use of powerful single cell RNA-sequencing, or the technique that allows for viewing the information on individual cells.

Creating treatment options in the future using the information from studying ‘mini eyes’

When studying the ‘mini eyes’, the research team also learned that Müller cells are also involved in Usher syndrome. Müller cells are responsible for metabolic and structural support of the retina. They help to maintain retinal health and proper functioning.

The researchers discovered that cells from people with Usher Syndrome have genes that are abnormal, and are turned on forming protein breakdown and stress responses within the retina. They want to eventually reverse the abnormal genes that become activated and believe this could potentially prevent the progression of the disease.

“Although a while off, we hope that these models can help us to one day develop treatments that could save the sight of children and young people with Usher syndrome,” said Jane Sowden, professor of Developmental Biology & Genetics at UCL, and senior author of the study. “In the future, it may be possible to edit a patient’s DNA in specific cells in their eyes to avoid blindness” she continued.