Columba ophthalmologist Stephen Tsang's research with a special type of adult stem cells suggests stem cells transplants may soon be used to prevent vision loss.

1. Can Stem Cells Restore Vision?
Stephen Tsang’s research
with a special type of adult
stem cell suggests stem
cells may soon be used to
prevent vision loss.
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continue the slideshow.
Photo: National Eye Institute

2. Can Stem Cells Restore Vision?
Most cases of vision loss
in the U.S. are caused by
the loss of pigmented cells
in thin layer in the retina.
Pigmented Cell Layer
The pigmented cells (left)
keep the eye’s light-
sensing cells healthy.
When the pigmented cells
die, light-sensing cells
soon follow.
Loss of Pigmented Cell Layer
Surface and cross-section views of a healthy human retina
(top) and a degenerating retina from a patient (above). Photos:
Stephen Tsang.

3. Can Stem Cells Restore Vision?
Age-related macular
degeneration (AMD) is the
most common disorder
caused by pigmented cell
degeneration.
In AMD, the loss of
pigmented cells in the
center of the retina impairs
central vision.
By 2020, it is estimated
that 14 million people over
65 in the U.S. will have
AMD.
The retina of a patient with AMD (top), and the effect of AMD
on central vision (above). Photos: Stephen Tsang and the
National Eye Institute.

4. Can Stem Cells Restore Vision?
At Columbia University
Medical Center,
ophthalmologist Stephen
Tsang is testing ways to
replace lost pigmented
cells.
Induced pluripotent stem
(iPS) created from the
patient’s own skin, could
potentially provide
personalized
replacements.
“IPS cells would be like
rejuvenating the body with
A colony of induced pluripotent stem (iPS) cells. baby cells,” Tsang says.
Photo: Stephen Tsang

5. Can Stem Cells Restore Vision?
Tsang starts with iPS cells
derived from a 53-year-old
donor.
“We use a cocktail of
growth factors to push
them into making retinal
cells.”
The new pigmented cells
look and act like native
cells (left), which have a
hexagonal shape in the
eye.
Pigmented cells derived from human iPS cells (left) are
morphologically similar to native retinal pigmented
cells(right). Photos: Stephen Tsang

6. Can Stem Cells Restore Vision?
Tsang’s latest study
shows that iPS-derived
retinal cells can restore
vision.
Tsang transplanted the
human cells into the
pigmented layer of mice
with a type of macular
degeneration.
Pigmented layer
Image: National Eye Institute, National Institutes of Health

7. Can Stem Cells Restore Vision?
The transplanted cells
integrated into the eye’s
Transplanted retina pigmented cell layer.
cells
Measurements of
electrical activity from
the grafted cells showed
they improved retinal
function.
Transplanted retinal cells five months after
transplantation. Photo: Stephen Tsang

8. Can Stem Cells Restore Vision?
The eye is the ideal testing
ground for iPS therapies, says
Tsang.
“The eye is a transparent and
accessible organ, and that’s a
big advantage.
“We can put cells into the eye
and monitor them every day
with routine non-invasive
clinical exams.” says
New optical coherence tomography (OCT) technology makes
investigation of the human retina fast and painless. Photo: Stephen
Tsang.