Novel eye drops may reverse glaucoma symptoms
London, Aug 6 (ANI): In an Italian study, researchers have found that a new type of medicated eye drop may be able to reverse symptoms of glaucoma.
Glaucoma, the world’’s leading cause of blindness, is caused by pressure inside the eye - intraocular pressure - that damages cells in the optic nerve.
In the study of rats and human patients, researchers found that drops containing a nerve growth factor may stop these cells dying, and actually improve vision.
Sometimes, it is possible to control the build up of intraocular pressure through other techniques, but once pressure starts damaging optic nerve cells, called retinal ganglion cells (RGCs), it can be impossible to recover that lost function.
And often people with glaucoma do not seek expert help until the condition is already relatively advanced.
For the current study, researchers from the University of Rome, treated rats with symptoms of glaucoma with eye drops containing nerve growth factor.
They observed that the animals who were given the eye drops showed decreased levels of RGC death compared with those who did not receive the treatment.
Later, the researchers tested the drops in three human patients whose intraocular pressure had started to be controlled, but who still showed signs of progressive deterioration in their vision.
They found that vision improved in two of the patients, while in the other it was stabilised. The improvements lasted up to 18 months after the eye drops were applied.
Apparently, nerve growth factor triggers chemical changes within cells that prevent them from dying in response to damage, and it might also enable cells whose function had begun to be damaged to bounce back.
In addition, it might boost the capacity of healthy RGCs to form new connections within the optic nerve, to compensate for any damage that had already taken place.
But, nerve growth factor cannot rescue RGCs that have already died.
“Although neuroprotection in glaucoma has already been attempted with several compounds, this is the first time that an improvement in visual function is observed in patients with advanced optic nerve damage,” The BBC quoted lead researcher Dr Stefano Bonini as saying.
David Wright, chief executive of the International Glaucoma Association, warned against drawing firm conclusions from such a small study, but he said that the results were encouraging.
He said: “There have been many false dawns in the search for neuro-protective agents for the treatment of glaucoma and it is a feature of research on other compounds that early promise does not always translate into clinical effectiveness when larger studies are undertaken.
“However, this research would seem to indicate both effectiveness and acceptability as to the means of drug delivery.
“If these early indications are carried through to wider trials and there are no other problems, then this has the potential to open a completely new method of treating glaucoma and of preventing unnecessary visual loss in the future.”
The study has been published in Proceedings of the National Academy of Sciences.