Eyes growing in a lab dish may sound like science fiction, but they’ve taken scientists a step closer to curing a major form of blindness.
Scientists at University College London have created the first artificial retinas in the lab from children with a condition called Usher syndrome.
The eerily small eyes appear to have a pupil, although this is just pigment in the retina.
Their use in the Usher syndrome study provided important new evidence of what happens in the eye that causes retinal degeneration – a major cause of blindness in which light-sensitive cells called rods and cones die.
This could help more than 30,000 people in the UK who are at risk of becoming blind due to inherited diseases, and provide hope to the 60,000 older people suffering from age-related macular degeneration, the most common cause of severe vision loss in people over 50.
Scientists at University College London have created the first artificial retinas in the lab from children with a condition called Usher syndrome
What is Usher syndrome?
Usher syndrome is a rare genetic disease that affects hearing and vision.
It causes deafness or hearing loss and an eye disease called retinitis pigmentosa (RP).
Sometimes, it also causes balance problems.
People with Usher syndrome are born with this syndrome, but they are usually diagnosed as children or adolescents.
There is no cure for Usher syndrome, but treatments can help people manage problems with vision, hearing, and balance.
Source: National Eye Institute
The study took skin cells from young patients with the rare genetic disease Usher syndrome at GOSH, to reprogram their cells to make stem cells, which can become any cell in the body.
The researchers simulated the processes seen in babies in the womb, over the course of nine months in the laboratory, to get seven types of cells to form a delicate pattern, becoming the tiny retina — the thin layer around the eyeball that detects light.
This allowed the researchers to see what happens in Usher syndrome, a genetic disease that leads to blindness as well as hearing loss.
An important role is played by cells called Müller cells, which criss-cross the retina and provide energy to the eyes.
This breakthrough adds to the growing evidence (SUBS – please keep it) that Müller cells are involved in all types of retinal degeneration, possibly because they are damaged in some people, and do not support the photosensitive cells in the retina.
“A breakthrough in the field that many scientific teams are working on,” said Jane Soden, professor of developmental biology and genetics at the Great Ormond Street Institute of Child Health at UCSD, lead author of the miniature eye study and conducting research at GOSH.
I believe that within 10 years many cases of hereditary blindness will be reversible.
Many people think that the miniature eyes are similar to a scene in Blade Runner, where the eyes are made in a dish to be used for clones.
But this retina in a dish really helps us see what’s going on in the back of the eye, which is important for Usher syndrome and could in the future help develop more complex treatments like age-related macular degeneration.
Small eyes, about 1 millimeter (0.04 inch) in diameter, can be seen developing earlier problems with the light-sensing rod cells (pictured), than small eyes made from the cells of healthy children
The study, published in the journal Stem Cell Reports, made small retinas from the stem cells of three children with Usher syndrome.
The condition affects around 10,000 people in the UK and causes their eyesight to slowly deteriorate until they become blind as adults.
The miniature eyes, about 1 millimeter (0.04 in) in diameter, can be seen developing earlier problems with the light-sensing rod cells, than the tiny eyes made of the cells of healthy children.
It became clear that the Müller cells in the retina were damaged, and possibly dying, due to a genetic error.
This may have an indirect effect on the rods and cones of the eye.
If Müller cells are important in Usher syndrome, they are likely to be important in different types of retinal degeneration.
This means that they could play a role in other diseases that include retinal degeneration, such as the devastating age-related eye disease, which affects about one in 40 people over the age of 50.
The findings on Müller cells, and the clear signs of stress in the light-sensing rod cells, came from an analysis of 40,000 cells in the tiny eye.
The researchers studied RNA – the molecule that converts the body’s instructions from DNA into proteins.
In the future, scientists hope to develop drugs that can block the processes in the eye that lead to blindness.
More small eyes can be used to test these treatments.
What is dry macular degeneration?
Dry macular degeneration is a common eye disorder among people over the age of 65.
It causes blurred or impaired central vision due to the thinning of the macula, the part of the retina responsible for people’s direct line of sight.
More than 1.75 million people suffer from it in the United States. The prevalence of the condition in the UK is not clear.
The wet form of the disorder is caused by leaking blood vessels under the retina and causes more sudden vision loss than the dry form.
Dry macular degeneration develops gradually, affecting people’s ability to do things, such as read, drive, and recognize faces.
Symptoms are usually painless and include:
- Visual abnormalities, such as the appearance of curved straight lines
- Central vision impairment
- The need for brighter lights
- Difficulty adjusting to low-level lights
- Unclear printed words
- Decreased color brightness
- Difficulty recognizing faces
Dry macular degeneration usually affects both eyes eventually.
It rarely causes blindness because peripheral vision is not affected.
The cause is not clear and may be a combination of genetic and environmental factors, such as smoking.
It can be prevented with routine eye exams, managing conditions such as high blood pressure, not smoking and eating well.
There is no cure.
Treatment may include seeing a rehab specialist or having telescopic lens implant surgery.
Source: Mayo Clinic