A hole in the retina can cause your vision to become patchy or blurry.
Christoph Burgstedt/Science Photo Library
A transplant of human stem cells appears to close a hole in a monkey’s retina and improve vision, offering hope for a new approach to treating a type of age-related vision loss.
As we age, the clear gel-like fluid in our eyes can thicken and pull on the retina. This can cause holes in the tissue, causing blurred or spotty vision. Doctors usually graft tissue from other parts of the eye into the retinal hole, but recurrence may occur.
To test other approaches, Michiko Bandai Doctors at Kobe City Eye Hospital in Japan have grown stem cells derived from human fetuses until they become precursor cells for retinal cells.
They transplanted the progenitor cells into a 1-millimeter-wide hole in the retina of the snow monkey’s right eye (cynomolgus monkey) struggled with vision tests in another study.
Mandai’s team trained the monkeys to perform a visual acuity test, using only their right eye to fixate on one of hundreds of dots flashing on a screen.
Before implantation, only 1.5 percent of the dots were fixated with gaze. Six months after implantation, gaze was fixed at points 11 to 26 percent across three tests.
The results suggest that the implants improved the monkeys’ vision, but clearly the monkeys say they can’t explain exactly how much better it was. Marius Adele At the Technical University of Dresden, Germany.
Further studies need to be done on larger groups of non-human animals, but if these studies are successful, this will be a promising result, as our eyes are very similar to those of other primates. The approach would probably work in humans, he says.
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