New Eye Drop Could Save Sight of Millions

Friday, 14 August 2009 12:13 Last Updated on Friday, 14 August 2009 13:05 Written by Kristie McNealy M.D.

A new eye drop studied by researchers in Italy has the potential to save the site of millions of people around the world.

The experimental drops, which contain nerve growth factor (NGF), were studied in both rats and humans with glaucoma.

Glaucoma is a serious disease of the eye in which increased pressure within the eye damages the optic nerve and retinal ganglion cells (RGCs).Â Glaucoma impacts about 70 million people in the world, and is the second most common cause of blindness. (See below)

Until now, doctors have been able to control intraocular pressure using medication, but they had no way of reversing the damage to the cells of the eye once they had occurred.Â This new study provides hope that doctors will one day be able to reverse and prevent vision loss due to glaucoma.

Researchers from the University of Rome gave drops containing nerve growth factor to rats with increased eye pressure, and found that fewer RGCs died when the drops were used.Â After these positive results, they moved on to human patients with advanced glaucoma.Â After just three months of treatment, the patients had improvements in visual field, optic nerve function, contrast sensitivity, and visual acuity.

NGF first drew the interest of Dr. Stefano Bonini and is colleagues when other researchers successfully used nerve growth factor to restore brain tissue in Parkinson's and Alzheimer's patients. Because of its impact on the nerve cells in the eye and brain, NGF has the potential to treat other neurodegenerative diseases as well.

According to Dr. Bonini, this was the first time that NGF eye drops have shown potential as a treatment for glaucoma.Â However, like most medical research, the study of NGF to treat glaucoma is in the earliest stages, and more research will be needed to determine whether NGF drops really are a miracle cure for glaucoma sufferers.

Glaucoma is the 2ndÂ most commonÂ cause of blindness

Â Glaucoma

Glaucoma is caused by high pressure inside the eye damaging the optic nerve. The major risk factor for most glaucomas is increased intraocular pressure.

Intraocular pressure is caused by the production of liquid, aqueous humor, by the eye and its subsequent drainage through the trabecular meshwork. Aqueous humor flows from the ciliary processes into the posterior chamber. It then flows through the pupil of the iris into the anterior chamber. From here the trabecular meshwork drains aqueous humor into the general blood circulation.

In open angle glaucoma there is reduced flow through the trabecular meshwork; in angle closure glaucoma, the iris is pushed forward against the trabecular meshwork, blocking fluid from escaping.

Reference: Lambiase A, Aloe L, Centofanti M, Parisi V, Mantelli F, Colafrancesco V, Manni GL, Bucci MG, Bonini S, Levi-Montalcini R.Â Experimental and clinical evidence of neuroprotection by nerve growth factor eye drops: Implications for glaucoma. PNAS published online before print August 3, 2009.Â doi:10.1073/pnas.0906678106

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