Science is always pushing the bar of what’s possible, but sometimes it really outdoes itself.
In recent years, many of the most exciting breakthroughs in biology and medicine have
surrounded the human eye… but none more so than the seeming total restoration of vision, itself.
This is Unveiled, and today we’re taking a closer
look at some exciting developments that are enabling blind people to see again.
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According to figures from the World Health Organization, there are around one billion people
worldwide with some form of visual impairment, and around forty million of those are blind. Blindness
isn’t a straightforward diagnosis, however. It comes in degrees of severity and there are
a number of causes, leading to various types of blindness - some of which medicine has more
control over, while others it doesn’t. Whether a person is made blind by a genetic condition,
by injury, by age-related sight loss, or by any other means, it has a major impact on how
they live their lives. The WHO estimates that some eighty percent of visual impairment can
either be prevented or cured… but, more often than not, total blindness is billed as an irreversible
condition. Therefore, it’s little wonder that some recent experiments have caught global attention.
The London Project to Cure Blindness has been one of the organizations leading the way. In 2018,
it released details of patients regaining sight “after being the first to receive retinal tissue
engineered from stem cells”. The trial was run on two people - a woman in her 60s and
a man in his 80s - both of whom were suffering from severe age-related macular degeneration,
one of the most common causes of sight loss. Importantly, neither was fully blind,
but they both could no longer read or complete many daily tasks. It’s
very possible that blindness would have set in before long, but the trial had a major
impact. A stem cell patch was fashioned for them, and delicately placed under the retina,
onto the back of their eyes, where macular degeneration takes hold. Within twelve hours,
both were able to read again, reporting a dramatic and total improvement in what they could see.
The study is actually one in a long list of similar studies,
dating back to the early 2000s, where science has experimented with stem cells in the eye. In 2021,
reports emerged of another success, this time staged by the company Regenerative
Patch Technologies, who again treated patients with severe age-related macular degeneration,
and again reported some major improvements in the vision of participants. However, until recently,
most studies have either relented from or haven’t had much success in tackling full
blindness. We have developed ways to stop, slow and even reverse worsening eyesight,
under some conditions, but bringing back totally lost vision is a different matter.
In 2022, reports emerged regarding another study that did seemingly manage to cure the blind,
however. It was conducted by a team at Sweden’s Linköping University,
and twenty people took part, including fourteen who were completely blind. In this case,
all participants had developed severely damaged corneas. The cornea is at the
very front of the eye, the transparent film that covers the pupil and iris.
Again, damaged or diseased corneas are a prominent cause for sight loss worldwide.
However, corneal transplants are possible, and can prove effective. One problem, though,
is that we’re low on people willing to donate their corneas after they’ve died.
This study broke new ground by finding an alternative solution in pig’s skin. The team
was able to construct cornea replacements out of pig skin, which contains collagen,
which is a key ingredient in the cornea. The new product was then fitted into participants’ eyes,
with some reporting not just improved but perfect vision post-op. As pig-skin corneas could be easy
to mass produce, the hope is that this switch might one day cure corneal blindness completely.
Beyond stem cell therapy and transplants, some scientists are hitting right at the source for
blindness, through CRISPR-cas9 gene editing. This long debated modern technology promises
so much in terms of humans one day having full control over their own biologies. With blindness,
in particular, one goal is to effectively rewrite certain gene mutations that are
known to cause sight loss, remove them from the patient, and therefore allow them to see again.
So far, there have been positive but varied results. For example, in late 2022, the US
biotech company Editas Medicine released details of one study, featuring fourteen participants,
three of which experienced vastly improved vision as a result of its methods. In this case,
the focus was on those with a rare and specific congenital condition, known
as Leber Congenital Amaurosis 10. Participants were injected with a CRISPR solution designed to
remove one particular protein. The process did achieve “clinically meaningful improvements”,
but in less than twenty-five percent of cases. In part because Leber Congenital
Amaurosis 10 affects very few people in total, Editas paused the trial soon after completing
the first wave. Therefore, it remains to be seen how much further this treatment could be taken.
But, finally, there is another promising possibility in technology. The concept of
smart glasses is by now well known, although no single product has yet to truly take off.
Beyond simply being an ultra-convenient gadget, however, many researchers believe
physical tech like this could hold the key to the restoration of sight. In the Netherlands,
especially, research is quickly taking shape. NESTOR is a Dutch,
multi-partnered initiative geared towards developing a “neuroprosthesis” to effectively
bypass the eye itself, while still generating sight inside the brains of its user. Meanwhile,
Envision is one Dutch-based company already building a product to achieve that.
While designs do differ, most are targeting camera-glasses that wirelessly connect to
an implant (or chip) inside the brain. This chip is then able to convert the photographic data it
receives into signals that are understandable in the brain’s visual cortex. From here,
the information should present itself to the user in much the same way as unimpaired sight does. The
tech has replaced the eye itself, meaning that any and all problems affecting the eye should no
longer result in blindness. It is still a young technology, and mostly untested on humans. One
major problem is that such glasses need to be as low power as possible, due to the risk of
increased electrical activity in the brain having serious adverse effects. However, there is growing
confidence that a tech solution is possible, with the race firmly on to make it a reality.
Which of these solutions do you think shows the most promise? From stem cells to transplants,
from edited genes to artificial connections, it could be that we’re on the brink of a
major health achievement. Because that’s how scientists are making blind people see again.
What do you think? Is there anything we missed? Let us know in the comments, check out these other
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