Vision loss pinpointed and test developed

Glaucoma threatens the sight of millions each year and one group of American scientists think they’ve pinpointed the location where vision loss occurs, while an engineer has developed a hand-held instrument to detect the disease

Scientists pinpoint where glaucoma strikes

In glaucoma, the optic nerve – which sends signals from the eye to the brain – is damaged and research from the Kennedy Krieger Institute offers novel insights into the cellular and molecular mechanism operating in the optic nerve head in the mouse models. At a specific location, astrocytes – star-shaped glial cells in the brain and spinal cord – demonstrate properties that appear to make them a critical factor in visual blinding.

 “These findings are very exciting because they give us several novel targets for future interventions,” said Dr Nicholas Marsh-Armstrong, senior study author. “I believe these findings put us on the cusp of discovering a treatment for glaucoma that may also have relevance for a number of other neurodegenerative diseases.”

The astrocytes also remove the debris of neurons – cells that die in neurodegenerative disorders – a finding which may be important for glaucoma and other neurodegenerative disease.

 At the same site, researchers found abnormal forms of a gamma synuclein – a protein similar to alpha synuclein which is known for its role in cell loss in Parkinson’s, suggesting a similar biological process may unfold at this specific anatomical location.

Future studies will look at the novel pathway and molecular/cellular mechanism to understand exactly what happens in glaucoma and what can be controlled pharmacologically to slow the disease down.

Opthalmologists currently test for glaucoma using tonometry – a test of the intraocular eye pressure – but an engineer in Arizona has developed a simple home test to detect the disease.

It uses a system of micro-force centres, specially designed microchips and maths-based programme procedures to gently rub the eyelid to check the intraocular pressure.

“You simply close your eye and rub the eyelid like you might casually rub your eye,” said Eniko Enikov. “The instrument detects the stiffness and, therefore, infers the intraocular pressure.”

The device can be used in situations difficult or impossible with current test, and can also be used to measure the drainage of intraocular fluid.