The news has been buzzing with reports of a new eye drop that may one day allow for cataracts
to be treated without surgery. But donβt cancel that cataract surgery
consultation just yet. While this research may show initial promise, it
has yet to be tested in humans or approved for patient use.
Chinese and American scientists and ophthalmologists have found that a
natural chemical may stop the development of cataracts, the leading
cause of blindness worldwide. Named lanosterol, the chemical was found
to be missing in children who had developed a rare form of childhood
cataracts. In contrast, the chemical was found in their parents who did
not have the condition. The researchers developed an eye drop solution
made of lanosterol and tested the solution on dogs, rabbits and
synthetic cataracts developed in labs using cells from human lenses.
They found that the drops shrank cataracts significantly in all three
groups.
βIf this treatment is successfully tested in humans and approved for
patient use, it could be a promising alternative for people living in
low-resource areas, where it is difficult to access cataract surgery,β
said Ravi D. Goel, M.D., a clinical spokesperson for the American
Academy of Ophthalmology and cataract surgeon at Wills Eye Hospital.
βHowever, itβs still too early to tell if these eye drops are a viable
treatment.β
The researchers are not yet sure of the exact mechanism by which
lanosterol causes the cataracts to shrink, nor do they know whether or
not there are any risks in using lanosterol clinically in human eyes.
Itβs likely that this research will continue to evolve, so stay tuned!
Cataracts, a leading cause of blindness in humans, may one day be treatable with eye drops
instead of surgery.
Surgery to treat cataracts is not available to everyone. Treatment with eye drops could be a game changer.
In the journal Nature, a study led by the University of
California-San Diego (UCSD) shows how a solution containing a natural
steroid that can be given via eye drops decreased
The lenses in our eyes are made mostly of crystallin proteins that have two jobs to do - they
allow us to change focus and they keep the lens clear. Nobody knows exactly how they do this.
Cataracts is a condition that develops when the delicate structure of the crystallin proteins is
disrupted and they start to form clumps and make the lens cloudy.
The lens is also rich in a molecule called lanosterol that is an essential building block of many
important steroids in the body. Lanosterol is synthesized by an enzyme called lanosterol
synthase.
The researchers began to look into lanosterol because they found children with an
inherited form of cataracts had the same gene mutation that blocked lanosterol
synthase.
They had a hunch that perhaps in normal eyes, where lenses are enriched with lanosterol, it stops
the cataract-forming proteins from clumping.
Lanosterol decreased clumping in cataract-forming proteins
The researchers ran three sets of experiments, starting with lab cells and progressing to animals.
First, in human lens cells, the team found
lanosterol decreased clumping in cataract-forming proteins. They then
showed treatment with lanosterol reduced cataracts and increased lens
transparency in
rabbits.
Fast facts about cataracts
Cataracts account for 51% of world blindness
Most cataracts develop later in life
Risk factors include too much sun, diabetes, tobacco and alcohol.
An eye drop tested on dogs suggests that cataracts,
the most common cause of blindness in humans, could one day be cured
without surgery, a study has said.
A naturally-occurring molecule
called lanosterol, administered with an eye dropper, shrank canine
cataracts, a team of scientists reported in Nature.
Currently the
only treatment available for the debilitating growths, which affect tens
of millions of people worldwide, is going under the knife.
While
surgery is generally simple and safe, the number of people who need it
is set to double in the next 20 years as populations age. And for many,
it remains prohibitively costly.
The chain of research leading to
the potential cure began with two children β patients of lead researcher
Kang Zhang of Sun Yat-sen University in Guangzhou, China β from
families beset with a congenital, or inherited, form of the condition.
Dr
Zhang and colleagues discovered that his patients shared a mutation in a
gene critical for producing lanosterol, which the researchers suspected
might impede cataract-forming proteins from clumping in normal eyes.
In a first set of lab experiments on cells, they confirmed their hunch that lanosterol helped ward off the proteins.
In subsequent tests, dogs with naturally-occurring cataracts received eye drops containing the molecule.
After six weeks of treatment, the size and characteristic cloudiness of the cataracts had decreased, the researchers reported.
“Our
study identifies lanosterol as a key molecule in the prevention of lens
protein aggregation and points to a novel strategy for cataract
prevention and treatment,” the authors concluded.
Cataracts account for half of blindness cases worldwide.
“These
are very preliminary findings,” said J Fielding Hejtmancik, a scientist
at the US National Eye Institute, who wrote a commentary also published
in Nature.
“Before there are any human trials, the scientists
will probably test other molecules to see if they might work even
better,” he said.
Drops Show Promise as Nonsurgical Cataract Treatment
Eye drops may offer new approach for research, expert says
By Dennis Thompson
HealthDay Reporter
WEDNESDAY, July 22, 2015 (HealthDay News) — Eyes clouded by cataracts may one day be treated with drops rather than surgery, a new animal study suggests.
Today, surgery is the only means of treating cataracts, the leading cause of blindness in the world. Doctors extract cloudy lenses and replace them with artificial lenses.
But researchers have discovered that an organic compound called lanosterol can improve vision by dissolving the clumped proteins that form cataracts,
said study lead author Dr. Kang Zhang, chief of ophthalmic genetics
with the Shiley Eye Institute at the University of California, San
Diego.
Eye drops containing lanosterol completely cleared the vision
of three dogs with naturally occurring cataracts after six weeks of
treatment. The drops improved vision for four other cataract-afflicted
dogs, according to findings published July 22 in the journal Nature.
“The results we have point to a new nonsurgical treatment of
cataracts that can be used for people who might have moderate cataracts
or do not have access to surgery,” Zhang said.
These findings “point to a new direction in cataract research,”
at a time when there’s huge pressure to come up with a better way of
treating cataracts, said Dr. J. Fielding Hejtmancik, a senior
investigator at the U.S. National Eye Institute (NEI).
The aging of the baby boom population is expected to fuel a
huge increase in cataracts, since most occur as part of the aging
process, Hejtmancik said.
It’s already occurring. Between 2000 and 2010, cases of
cataracts in the United States rose 20 percent, from 20.5 million to
24.4 million, according to the NEI. By 2050, that number is expected to
double to an estimated 50 million.
Cataract surgery is a safe and routine procedure, but demand
will rise dramatically. “You’re going to probably double your surgical
requirements within the next 10 years,” Hejtmancik said.
Lanosterol eye drops could provide a cheaper and easier
alternative for cataract treatment in many people, and perhaps prevent
cataracts in someone at risk for developing them, Zhang and Hejtmancik
said.
More than 20 million Americans have cataracts, a leading cause of vision loss and blindness, and right now surgery is the only available option to correct the problem. But new research raises the hope that someday, cataracts could be cured with simple eye drops.
Cataracts
occur when the normally transparent lens of the eye gradually clouds
over due to an accumulation of proteins that malform and clump together.
The condition often develops as people get older; the National Eye Institute estimates that by the age of 80, more than half of all Americans either have a cataract or have had surgery to remove one.
Now
researchers from the University of California, San Diego have
discovered a promising alternative to surgery: an eye drop that
effectively reversed cataracts in animal testing. Their findings are
published in the journal Nature.
Their work began with the cases of three children who had a
severe cataract condition that ran in their family. The scientists
sequenced the children’s genomes and identified a genetic mutation that
interfered with the production of lanosterol, a naturally occurring
steroid in the body. From that clue, they decided to test whether
lanosterol might have the ability to prevent or even eliminate
cataracts.
They tested it first in lab cultures, then in the
cataract lenses of rabbits, and finally on 7 dogs from 3 species (black
Labrador, Queensland Heeler and Miniature Pinscher ) who were suffering
from adult-onset cataracts, which can happen in canines as well as
humans.
For the dogs’ treatment, they sedated the animals and
injected lanosterol (100 mg)-loaded nanoparticles into the vitreous
cavity of the eye, the area behind the lens which is filled with a
gel-like substance called the vitreous humor. The treatment eyes then
received lanosterol in topical eye drops, one drop three times a day for
6 weeks.
“Treatment by lanosterol,” the researchers write,
“significantly decreased preformed protein aggregates both in vitro and
in cell-transfection experiments.”
Before and after photos showing dogs’ cataracts diminished after lanosterol treatment.
LING ZHAO ET. AL./NATURE
The
dogs who received the treatment showed notable improvement in their
cataracts, graded on a scale from zero (no cataract) to 3 (extensive
opacity of the entire lens).
“I was pleasantly surprised, even in
principle, this treatment should work,” one of the authors of the study,
Dr. Kang Zhang, professor of ophthalmology and chief of ophthalmic
genetics at UC San Diego, told CBS News.
Other scientists in the field were impressed by the results.
In
a commentary published in Nature to accompany the study, J. Fielding
Hejtmancik, of the Ophthalmic Genetics and Visual Function Branch of the
National Eye Institute, suggested the research could lead to
non-surgical prevention and treatment of cataracts.
“The potential
for this finding to be translated into the first practical
pharmacological prevention, or even treatment, of human cataracts could
not come at a more opportune time,” he writes.
“This is a really
comprehensive and compelling paper - the strongest I’ve seen of its kind
in a decade,” Jonathan King, a molecular biologist at Massachusetts
Institute of Technology who researches cataract proteins, told Science
magazine. “They discovered the phenomena and then followed with all of
the experiments that you should do - that’s as biologically relevant as
you can get.”
Before testing can begin in humans, Zhang said the
team will need to check the toxicity of lanosterol, even though it is “a
product of our own body. Then we will need to formulate the drug as
the most efficient eye drop for a human trial.”
In a Nature podcast, Zhang said he and his colleagues hope to begin human trials within a year.
A cataract is the clouding of the eyeβs lens and accounts
for over half of all cases of blindness worldwide. Though cataracts can
be effectively treated with surgery, itβs costly and requires trained
surgeons. This is a problem for developing countries with poor health
systems. Drug treatments have the potential to be a game changer in
providing cheap and accessible treatment, but there are many hurdles. A
new study that used eye drops to shrink cataracts in dogs may have made
an important step in overcoming them.
The vast majority of cataracts are age related,
but some can develop the condition as a result of an injury or a
genetic defect. Researchers became more interested in researching how
this defect led to cataracts. Professor Kang Zhang, from the University of California San Diego, and his research team studied two families who had children born with cataracts, known as congenital cataracts.
They found that those with congenital cataracts had
a mutation in the gene that produces a small molecule known as
lanosterol. The healthy version of this molecule usually prevents
cataract-causing proteins from clumping together. In the abnormal
version of this molecule, however, cataract-causing proteins caused
cloudiness in the eyeβs lens.
Zhang and his research team went on to develop eye drops
that contained lanosterol as a drug treatment for cataracts. To test
whether the eye drops could reduce cataracts, researchers isolated
lenses from rabbits that had cataracts and placed them in a lanosterol
solution for six days. They found that this reduced cataract severity
and increased lens clarity.
βWe went on to test the effect of the eye drops in dogs with
cataracts. We gave them eye drops twice a day for six weeks and found
it had reduced the effect of cataract severity,β Zhang explains to
IFLScience.
Eye drops dissolved cataracts in dogs. Image credit: Kang Zhang
The study, published in Nature, only
lasted for a few months, so the cataracts are likely to have reoccurred
after the drops stopped, Zhang says. He does, however, believe that the
eye drops could play an important role in the prevention of cataracts
in those showing early signs. The ultimate βgoalβ is to develop a cheap,
effective drug that can be widely used in low-resource settings.
βYou cannot compare the improvements shown in this study
with surgery. With cataract surgery, you become 20 years old again; with
this one the lens is cleared up, but your vision can still be murky,β
he explains.
The study is quite important, Datiles says, as researchers
have discovered that a gene in a certain clinical pathway related to
cholesterol production caused cataracts. This is, however, only one of
the many pathways that can be used to alleviate cataracts.
βThere are other drops that do the same thing but use
different pathways. This is why we need multifunctional anti-cataract
agents that work together across multiple pathways to clear the lens,β
Datiles says.
βThereβs now scope to investigate how we can combine this drug with other ones to better improve treatment,β he adds.
According to Datiles, eye drops will become key in treating
cataracts, as surgery will not be able to cope with the growing needs of
the worldβs aging population. Thereβs already a backlog in many
developing countries as clinics cannot cope with the demand for
surgeries and, as a result, many become blind, Datiles says.
Scientists Have Developed an Eye Drop That Can Dissolve Cataracts
A whole lot better than surgery.
BEC CREW
23 JUL 2015
Researchers in the US have developed a new drug that can be delivered
directly into the eye via an eye dropper to shrink down and dissolve
cataracts - the leading cause of blindness in humans.
While the effects have yet to be tested on humans, the team from the
University of California, San Diego hopes to replicate the findings in
clinical trials and offer an alternative to the only treatment thatβs
currently available to cataract patients - painful and often
prohibitively expensive surgery.
Affecting tens of millions of people worldwide, cataracts cause the
lens of the eye to become progressively cloudy, and when left untreated,
can lead to total blindness. This occurs when the structure of the
crystallin proteins that make up the lens in our eyes deteriorates,
causing the damaged or disorganised proteins to clump and form a milky
blue or brown layer. While cataracts cannot spread from one eye to the
other, they can occur independently in both eyes.
Scientists arenβt entirely sure what causes cataracts, but most cases are related to age, with the US National Eye Institute reporting that
by the age of 80, more than half of all Americans either have a
cataract, or have had cataract surgery. While unpleasant, the surgical
procedure to remove a cataract is very simple and safe, but many
communities in developing countries and regional areas do not have
access to the money or facilities to perform it, which means blindness
is inevitable for the vast majority of patients.
According to the Fred Hollows Foundation,
an estimated 32.4 million people around the world today are blind, and
90 percent of them live in developing countries. More than half of these
cases were caused by cataracts, which means having an eye drop as an
alternative to surgery would make an incredible difference.
The new drug is based on a naturally-occurring steroid called
lanosterol. The idea to test the effectiveness of lanosterol on
cataracts came to the researchers when they became aware of two children
in China who had inherited a congenital form of cataract, which had
never affected their parents. The researchers discovered that these
siblings shared a mutation that stopped the production of lanosterol,
which their parents lacked.
So if the parents were producing lanosterol and didnβt get cataracts, but their children werenβt producing lanosterol and did
get cataracts, the researchers proposed that the steroid might halt the
defective crystallin proteins from clumping together and forming
cataracts in the non-congenital form of the disease.
They tested their lanosterol-based eye drops in three types of
experiments. They worked with human lens in the lab and saw a decrease
in cataract size. They then tested the effects on rabbits, and according to Hanae Armitage at Science Mag,
after six days, all but two of their 13 patients had gone from having
severe cataracts to mild cataracts or no cataracts at all. Finally, they
tested the eye drops on dogs with naturally occurring cataracts. Just
like the human lens in the lab and the rabbits, the dogs responded
positively to the drug, with severe cataracts shrinking away to nothing,
or almost nothing.
“This is a really comprehensive and compelling paper - the strongest
Iβve seen of its kind in a decade,” molecular biologist Jonathan King
from the Massachusetts Institute of Technology (MIT) told Armitage.
While not affiliated with this study, King has been involved in
cataract research for the past 15 years. “They discovered the phenomena
and then followed with all of the experiments that you should do -
thatβs as biologically relevant as you can get.”
The next step is for the researchers to figure out exactly how the
lanosterol-based eye drops are eliciting this response from the cataract
proteins, and to progress their research to human trials.
Could eye drops be an alternative treatment to cataract surgery?
Researchers have discovered a compound that reverses cataracts and is soluble enough to be used as eye drops, Science reports.
The research could be a stepping stone for research of future treatments.
If left untreated, cataracts can lead to blindness. The only
treatment is surgery to remove the lens, which is commonplace in the
United States but not available in many developing countries.
“Cataracts
in humans have been around as long as humans have been around, and this
is the first time in history that they’re using a nonsurgical approach
for their removal,” says Andrew Morgenstern, O.D., chair of AOA’s New
Technology Committee and a consultant with Booz Allen Hamilton whose
current assignment is with the Vision Center of Excellence at Walter
Reed National Military Medical Center in Bethesda, Maryland.
Crystallins
in our eyes work as chaperones to help prevent the clumping of
proteins, or aggregation of insoluble amyloids, that cause cataracts,
but crystallins can become overwhelmed as we age. Previous research had
shown that lanosterol, which belongs to a group of chemical compounds
called sterols, reversed cataracts. However, lanosterol was not
water-soluble enough to be included in an eye drop solution and had to
be injected into the eye.
In this new study, researchers tested 32 additional sterols,
focusing on Compound 29, which not only dissolved the amyloids in a lab
dish but also prevented the formation of new protein clumps.
Researchers then confirmed that Compound 29 reversed hereditary- and
age-related cataracts in mice and in human lens tissue removed during
cataract surgery.
Not an immediate option
One limitation of the study is that it was a mouse study, says Sue Lowe,
O.D., chair of the AOA Health Promotions Committee who practices in
Laramie, Wyoming. You can’t ask mice about their visual acuity.
“Every individual still interprets what they see differently,” she says.
Dr.
Lowe explains that a cataract might appear cloudy to the optometrist,
yet the patient says he or she can see well. On the other hand, another
patient may have a clearer-looking cataract, yet complain about poor
eyesight.
An animal model also means the research isn’t “going
anywhere fast,” Dr. Morgenstern says. But it could be a stepping stone
for research of future treatments.
The concept of eye drops as
cataract treatment isn’t new, Dr. Lowe says. A product was developed in
Russia using a compound called N-acetylcarnosine in eye drops to treat
cataracts. It’s available in the United States as a dietary supplement
but is not approved by the U.S. Food and Drug Administration. It was
patented by the research team in Russia, where most of the studies have
been conducted.
Drs. Morgenstern and Lowe agree that cataract
surgery will likely remain the primary treatment in the United States,
but an eye drop that improves cataracts could be a boon to the
developing world, even if it doesn’t eliminate the cataract altogether.
“Sometimes
the best treatment you can get for a patient is an improvement and not
necessarily a complete cure,” Dr. Morgenstern says. “If you can take an
individual with a 20/200 cataract and you can get them to 20/40
best-corrected vision with a simple eye drop, that’s pretty amazing
stuff.”
The AOA follows all research and new technology closely,
including potential new cataract treatment. Although these eye drops are
an interesting development, more research is needed regarding their
influence on visual health. For more information or help for better
vision, please visit the AOA website.
New Eyedrops Could Shrink Cataracts Without Surgery
By Charles Q. Choi, Live Science Contributor |
Eyedrops can shrink cataracts in dogs, which may prove a first step
toward a drug that can treat or even prevent cataracts in human eyes,
researchers say.
Cataracts
form when the eye’s lens grows cloudy, a condition that affects
millions of people and accounts for more than half of all cases of
blindness worldwide. Currently, the only treatment for cataracts is
surgical removal of the clouded lenses. Aging populations around the
world are predicted to require a doubling in the number of cataract surgeries in the next 20 years.
Cataracts often result from clumping of the proteins that make up the
lens. To learn more about how eyes normally prevent such clumping and
keep lenses transparent, scientists analyzed the genes of two related
families that both often suffered cataracts from birth. [7 Ways the Mind and Body Change With Age]
The researchers discovered that these families carried mutations in a gene
involved in manufacturing a small molecule known as lanosterol. Normal
versions of lanosterol in healthy eyes help prevent the kind of protein
clumping that leads to cataracts, while the abnormal version seen in
both families did not.
To examine what effects lanosterol might have on cataracts, scientists experimented on dogs with naturally occurring cataracts.
“There are many old dogs with cataracts,” said study co-author Kang
Zhang, an ophthalmologist at the University of California, San Diego in
La Jolla. “Our collaborators in China had them for another project in
cataract research, and we then treated these dogs with lanosterol.”
After six weeks of treatment with lanosterol eyedrops, lens cloudiness
and cataract size decreased in the dogs. Similar results were seen in
experiments with human lens cells and rabbit lenses on lab dishes.
“The most important implication is that we can treat cataracts with an eyedrop, not surgery,” Zhang told Live Science.
Still, “this is a preliminary study, and it needs further work and more
studies, as well as confirmation by other researchers,” Zhang
cautioned. “We will study the safety of this compound, and plan human
trials for treatment of cataracts.”
The scientists detailed their findings in the July 23 issue of the journal Nature.
![senior eye]](http://cdn1.medicalnewstoday.com/content/images/articles/297/297240/senior-eye.jpg)
