But perhaps there are other ways of protecting the cell. This idea of protecting nerve cells, neuroprotection, is an old one and was attempted by physicians in the past such as Bernard Becker at Washington University in St Louis. Recently the idea has surfaced again, at least partially as a consequence of many new discoveries in the fields of genetics, neurobiology, and pharmacology. But before proceeding further, the reader should know that, to date, there is no proof that there is any way to protect the nerves of patients with glaucoma other than lowering the pressure within the eye. Every other approach, so far, is something that is appropriate to do in addition to lowering intraocular pressure the appropriate amount, and not in place of lowering the intraocular pressure the proper amount.
Cells are factories.
They need fuel, they make wastes, they need instruments to utilize the fuel and dispose of the wastes, and they must have structural integrity in order to survive. The ganglion cells of the retina need sugar and oxygen, but they also need nerve growth factors to sustain them. They can be killed by their own waste products, such as the acids that result from burning sugars and fats, the ammonias that result from using protein. A toxin of special interest in glaucoma is glutamate, a substance which is essential for cell functioning, but which in excess can cause the death of the cell. The wall of the cell must be intact, but must function to let in those things it wants and keep out those things it does not want.