A new study suggests there may be a link between sildenafil, the active
ingredient in VIAGRA, and irreversible vision loss. Researchers at the
University of South Wales School of Optometry and Vision Science found
that sildenafil inhibited an enzyme which helps transmit light signals
from the retina to the brain in mice. The research also suggests that
patients who carry a common genetic mutation for the eye disease retinitis
pigmentosa could face the highest risk for vision loss.
So why should I care, I’m a man not a mouse, right?
Dr. Amanda Hoelscher explains why patients should tell their eye doctor
if they use VIAGRA or any other medications.
“We want male patients to be aware that there may be additional potential
risks to their vision by taking erectile dysfunction (ED) drugs. That’s
why it’s so important that men are straightforward with their eye
doctor regarding any and all medications they use and medical conditions
they are experiencing,” says Key-Whitman Eye Center's
optometrist Amanda Hoelscher, O.D.
“What we’ve known for some time is that according to the
Journal of Sexual Medicine, 3 to 11 percent of men taking VIAGRA will suffer temporary vision disturbances,”
Dr. Hoelscher says. These temporary symptoms include:
- Blurring of vision.
- Light sensitivity.
- Color vision changes.
“What we’re just learning now, is that there may be a possible
link for a risk of permanent vision loss due to ED drugs. The researchers
in this new study gave a single dose of sildenafil to both normal mice
and mice that carry a single copy of the mutant gene for retinitis pigmentosa.
Mice without the gene suffered temporary vision issues, but mice with
the genetic mutation experienced extended vision problems and also showed
early signs of cell death in the eyes,” explains Dr. Hoelscher.
What is retinitis pigmentosa and how could it harm my vision?
“Retinitis pigmentosa is a genetic disease that leads to progressive
vision loss. It predominately affects the rods in the eyes, which are
dispersed peripherally in the retina. Patients don’t actually go
blind, but they are left with irreversible tunnel vision,” says
Dr. Hoelscher. Night blindness is one of the early markers for the disease.
Dr. Hoelscher discusses the significance of the new study and prevalence
of VIAGRA use in the U.S.
Dr. Hoelscher notes that “While additional research is necessary,
these study findings are worth discussing with patients during an
eye health exam, because
one in 50 people are likely carriers of this recessive gene. However, most carriers of the gene don’t
realize it, because their vision is normal.”
“According to a 2011 article in
The New York Times, VIAGRA had been prescribed 35 million times, and based on a study conducted
by Express Scripts, 20 percent of men over the age of 45 have used the
medication. If further research confirms the link between sildenafil and
humans who carry a single copy of the mutant gene for retinitis pigmentosa
(as it did in the mouse study), a significant number of men could be affected,”
says Dr. Hoelscher.
ED drug users should speak openly with their eye doctors about potential
A vast number of medications can cause temporary and/or permanent vision
problems, not just ED drugs. “The better informed your eye doctor
is regarding your medication and medical condition details, the better
equipped he or she will be to provide the best vision care,” Dr.
As it pertains to this recent study, Dr. Hoelscher also suggests “VIAGRA
users ask their primary care physician to perform a simple blood test
to determine if they carry the mutant gene for retinitis pigmentosa. This
can help the patient better weigh the risks and benefits of using ED drugs
and also offer peace of mind.”