Japanese researchers have made a breakthrough in the field of vision restoration by successfully using human stem cells to restore sight in a monkey. The experiment, led by Mitiko Mandai from the Kobe City Eye Hospital, has opened up new possibilities for treating and preventing age-related blindness. The study focused on a common age-old disease known as a macular hole, which occurs when the vitreous body of the eye detaches from the retina, sometimes leading to a rupture in the macula – the central part of the retina responsible for central vision and processing light signals.
Macular holes can significantly impact the quality of life, causing gradual blurriness of vision and other symptoms. Current treatment methods, which are successful in only 90% of cases, have a major side effect of peripheral vision loss. This is because doctors typically move cells from the periphery of the retina to the center to close the holes.
In a novel approach to addressing this issue, the MTIKO team opted to create new cells instead of relying on the limited number of cells already present in the eye. They grew a layer of precursor retinal cells from human embryos in a test tube and transplanted them into the right eye of a snow monkey with a macular hole. The results of the experiment exceeded expectations, with the monkey showing a significant improvement in vision six months after the procedure.
To further study the effectiveness of the method, the researchers had to take a drastic step by removing the eye of the primate. This confirmed that new visual cells had indeed grown in the retina. The exact mechanism by which stem cells operate in the animal’s eye remains unclear, prompting further research to determine whether they form new cells independently or stimulate the regeneration of existing cells.
While the findings are promising, additional extensive testing is required before the method can be considered for human treatment. Nonetheless, the experiment underscores the potential of stem cells as a promising treatment approach for various ophthalmic conditions.