Holes in the retina can make vision patchy or blurry
Christoph Bergster/Science Photo Library
A transplant of human stem cells that sealed a hole in a monkey’s retina appeared to improve its vision, raising hope for a new way to treat age-related vision loss.
As we age, the clear, gel-like fluid in our eyes can thicken and pull on the retina. This can tear tissue, causing blurred or patchy vision. Doctors can usually move tissue from other parts of the eye into retinal holes, but in some cases, they can occur again.
To test other methods, Michiko Bandai She and her colleagues at the Kobe Eye Hospital in Japan grew stem cells from human embryos into precursors of retinal cells.
They transferred the precursor cells into a 1-millimeter-wide hole in the retina of the snow monkey’s right eye (black macaque) performed poorly on a vision test in another study.
Mandai’s team trained the monkey to complete a vision test, using only its right eye, requiring it to fixate on one of hundreds of dots flashed on a screen.
Before transplantation, it could only fixate on the 1.5% point. Six months after transplant, it zeroed in on points of 11 to 26 percent across three tests.
Results showed the transplant improved the monkeys’ vision, but apparently the animals couldn’t explain exactly how good it was, says Marius Adel at the Technical University of Dresden, Germany.
More studies in more non-human animals are needed, he said, but if those studies are successful, the approach could work in humans because our eyes are so similar to those of other primates.
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