Nerve growth factor eye drops to treat glaucoma

Since the discovery of nerve growth factor (NGF) in the 1950s, scientists have had great expectations for NGF in the treatment of neurodegenerative diseases. The main obstacle to overcome was the blood-brain barrier, which NGF does not cross when administered systemically. Our research group has recently demonstrated that topically instilled NGF eye drops are effective in treating several ocular diseases such as neurotrophic and autoimmune corneal ulcers. Pharmacodynamic studies have also shown that NGF eye drops have the ability to target the optic nerve and brain, thus finally opening-up avenues of research in pursuit of a novel drug for neurodegenerative diseases. In this review, clinical trials of systemically and topically administered NGF are discussed, as well as recent progress in the production of biologically active recombinant human NGF and innovative delivery routes. The pharmacological activity of NGF eye drops in ocular surface, retina and optic nerve diseases are also discussed.