To treat people at risk of blindness… Developing “miniature eyes” in the laboratory

With the great development witnessed by medicine every day, scientists succeeded in developing what they called “miniature eyes”, from stem cells taken from skin samples, in order to help people with a genetic disease that affects hearing and vision.

What is Usher Syndrome?

A genetic disease that affects hearing and vision, and is the most common genetic cause of combined deafness and blindness.
It affects approximately 3 to 10 out of every 100,000 people worldwide.
Children with Usher syndrome type 1 are often born deaf and their vision slowly deteriorates until they become blind by adulthood.
Although ear implants can help with hearing loss, there are currently no treatments for the cause of vision loss in Usher syndrome.

The new technique

Scientists have developed the three-dimensional ‘mini-eyes’ from stem cells generated from skin samples donated by patients with the syndrome at Great Ormond Street Hospital for Children.

In a healthy eye, cells that detect light, known as rods, are located in the back of the eye, specifically in the retina where images are processed.

To elaborate, the study’s first author, Dr. Ye Chuan Leung, of the Great Ormond Street Institute of Child Health at UCLA, said:”It’s difficult to study the delicate, inaccessible neurons of a patient’s retina, because they are intricately connected and located at the back of the eye.”
“Using a small biopsy of the skin, we now have the technology to reprogram the cells into stem cells, and then create retinas that have grown in the lab with the same DNA, and therefore the same genetic conditions, as our patients.”
The miniature eyes developed in this research allow scientists to study individual light-sensitive cells of the human eye, in more detail than ever before.
It is the first time that researchers have been able to watch the subtle changes in rod cells before they die.
The “mini-eyes” are being developed from cells donated by patients with and without the genetic defect that causes Usher’s syndrome, allowing the team to compare healthy cells with those that would lead to blindness.
Understanding these differences can provide clues to eye changes before a child’s vision deteriorates and help lead to early treatment.

What are rod cells?

Rod cells are photoreceptor cells in the retina.
It is called a bacillus because of its long, cylindrical shape.
These cells operate in lighter lighting conditions than do other photoreceptor cells, such as cone cells.
They are concentrated at the outer edges of the retina around the center of the retina, and are used for peripheral vision and vision in the dark.
How does “small eyes” help in treatment?

The team of scientists involved in the study believes that future research “will create miniature eyes from more patient samples, and use them to identify treatments, for example, by testing different drugs.”
It may also be possible to modify the DNA in specific cells, to avoid blindness.