New glaucoma test aids early detection

A new test for glaucoma could allow for the disease to be treated before sight loss begins.

Researchers believe that the pioneering test will allow for the diagnosis of glaucoma up to 10 years earlier than was previously possible.

The technique, labelled DARC, allows for health professionals to observe individual cell deaths at the back of the eye.

The University College London (UCL) Institute of Ophthalmology’s Professor Francesca Cordeiro, who led the research, told OT that the test provided an objective result indicating disease at a cellular level that had never been achieved before.

“Detecting glaucoma early is vital as symptoms are not always obvious. Although detection has been improving, most patients have lost a third of their vision by the time they are diagnosed,” she highlighted.

Professor Cordeiro explained that more than 40% of retinal ganglion cells had to be lost before a visual field defect could be detected.

“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 diseases,” she outlined.

Results of the first clinical trials with glaucoma patients using the test have been published in BRAIN. The initial trials tested the safety of the new procedure.

The technique uses a fluorescent marker that attaches to cell proteins when injected into patients. Sick cells appear as white fluorescent spots during eye examination. Patents for the technology are held by UCL Business.

Professor Cordeiro explained that while DARC may be difficult for optometrists to administer the test in its current intravenous form, researchers were developing an eye drop version of the test that optometrists would be able to use.

She emphasised that the development of the test had the potential to reduce the length of clinical trials for therapies used to combat glaucoma.

AOP clinical and regulatory officer, Henry Leonard, highlighted to OT that optometrists were always looking for ways to detect glaucoma as early as possible.

“The technique described in the study is likely to be too invasive to become part of routine optometric practice in the near future, but if a less invasive way of measuring cell apoptosis could be developed, this could be a useful tool in helping optometrists to detect glaucoma earlier,” he elaborated.

In the meantime, patients should still be advised to have a routine sight test at least once every two years, or more often if recommended by their optometrist, Mr Leonard emphasised.

The research was funded by the medical research charity, Wellcome Trust. Bethan Hughes, of the Wellcome Trust Innovations team, told OT that the technology had the potential to transform the lives of people who suffered sight loss from glaucoma.

“Loss of sight as you age is an incredibly difficult disability, impacting quality of life and independence,” she stressed.