- One in 10 glaucoma patients suffer from vision loss
by the time they are diagnosed with the condition because glaucoma is
- The new test, Detection of Apoptosing Retinal Cells or DARC, captures individual cell death and
detects the earliest signs of glaucoma.
- In future, this test can be used for the potential
diagnosis of other neurodegenerative conditions like Parkinson's,
Alzheimer's and multiple sclerosis.
A simple eye test known as Detection of Apoptosing Retinal Cells or DARC,
developed to help in early detection of the condition
that leads to irreversible blindness, glaucoma.
The test developed by a research team from the University College London (UCL) and
the Western Eye Hospital, allows doctors to view the death of individual nerve
cells, at the back of the eye.
‘The visualization of the fluorescent signals in the neuronal cells of the eye, provides an opportunity for the identification and assessment of neurodegenerative diseases like glaucoma.’
The findings are published in the
When there is an
accumulation of fluid in the front part of the eye, it leads to an
increase in eye pressure, causing damage to the optic nerve. Eventually, it
leads to blindness.
The blindness in glaucoma is as a
result of the death of retinal nerve cells, known as retinal ganglion cells (RGC),
at the back of the eyes. As the disease progresses, it results in the loss of
more cells. This process of cell death is called apoptosis.
occurs because majority of the patients suffering from glaucoma
are asymptomatic which results in late
diagnosis of the condition, often when vision loss has already set in.
According to the WHO, glaucoma is
the second leading cause of blindness.
Glaucoma affects 60 million
people in the world and around 1 in 10 suffering from the condition suffer from
loss of sight in both eyes. Though this condition affects older people
primarily, 1 in 10,000 babies born in the U.S is
likely to be affected by it.
In America, around 3 million
people have glaucoma and about 120,000 are blind from the condition.
The new test, DARC, will help in
early detection of the condition, followed by prompt treatment that can help
prevent loss of sight.
The test can be used for the
potential diagnosis of other neurodegenerative conditions like Parkinson's,
Alzheimer's and multiple sclerosis.
New Test - DARC
The test helps in the detection
of the dying or apoptosing cells of the retina and the technique is called
DARC or Detection of Apoptosing
A specially developed fluorescent
marker is injected into the patients. The marker attaches to the cell proteins.
On examination, the dying retinal nerve cells appear as white fluorescent
For examination, the equipment is used commonly during routine hospital eye examinations.
The first clinical trial was
carried out on a small number of glaucoma patients and compared with tests on
healthy people. This helped to establish the safety of
the test for patients.
Professor Francesca Cordeiro at
UCL Institute of Ophthalmology, who led the research, said "Detecting
glaucoma early is vital as symptoms are not always obvious. Although detection
has been improving, most patients have lost a third of vision by the time they
are diagnosed. Now, for the first time, we have been able to show individual cell
death and detect the earliest signs of glaucoma. While we cannot cure the
disease, our test means treatment can start before symptoms begin. In the
future, the test could also be used to diagnose other neurodegenerative
Professor Philip Bloom, Chief
Investigator at Western Eye Hospital, part of Imperial College Healthcare NHS
Trust, added: "Treatment is much more successful when it is begun in early
stages of the disease, when sight loss is minimal. Our developments mean we
could diagnose patients 10 years earlier than was previously possible."
Bethan Hughes, from Wellcome's
Innovation team said "This innovation has the potential to transform lives
for those who suffer loss of sight through glaucoma, and offers hope of a
breakthrough in early diagnosis of other neurodegenerative diseases. Loss of
sight as you age is an incredibly difficult disability, impacting quality of
life and independence."
Eventually, researchers hope that
DARC can be simplified for opticians to handle, which will enable the earlier detection of the disease.
Further investigations are needed
for the DARC test, so that it can be used not only to diagnose and treat
glaucoma patients but also other neurodegenerative
conditions like Parkinson's disease, Alzheimer's and Multiple
- Francesca Cordeiro et al. Real-time imaging of single neuronal cell apoptosis in patients with glaucoma. BRAIN; (2017) doi.org/10.1093/brain/awx088
- What is Glaucoma? - (https://www.aao.org/eye-health/diseases/what-is-glaucoma)
- Glaucoma Facts and Stats - (http://www.glaucoma.org/glaucoma/glaucoma-facts-and-stats.php)