New York: Our brain could actually be regulating the progression of glaucoma and other neuro-degenerative diseases, researchers say.

The result has implications in the pursuit of neuroprotective therapies.

Glaucoma is a neuro-degenerative disease where patients lose seemingly random patches of vision in each eye.

Scientists have long thought that glaucoma's progression is independent of - or uncontrolled by - the brain.

However, the study found that the progression of glaucoma is not random and that the brain may be involved after all.

The study said patients with moderate to severe glaucoma maintained vision in one eye where it was lost in the other - like two puzzle pieces fitting together (a 'jigsaw Effect').

This pattern of vision loss is in stark contrast to loss from a brain tumour or stroke, which causes both eyes to develop blind spots in the same location.

‘This suggests some communication between the eyes must be going on and that can only happen in the brain,’ said study's lead author William Eric Sponsel from University of Texas at San Antonio.

Sponsel found that the jigsaw effect begins at the earliest stages of glaucoma and discovered clues as to which part of the brain is responsible for optimising vision in the face of glaucoma's slow destruction of sight.

‘Our work has illustrated that the brain will not let us lose control of the same function on both sides of the brain if that can be avoided,’ Sponsel said.

The progression of Alzheimer's and Parkinson's diseases, which have neuro-degenerative biology similar to glaucoma, may also be actively mediated by the brain.

It seems likely that the same kind of protective mechanism will be at work with other neuro-degenerative disorders.’

The researchers say if the brain regulates neuro-degeneration - that is, if the brain controls how it loses control - then scientists now should be able to look for opportunities to slow or stop the progression of these diseases.

The study was published in Translational Vision Science & Technology (TVST).