Complementary therapy for the treatment of glaucoma: a perspective.

Although neuroprotective strategies and pharmaceutical agents have been initiated in the treatment of numerous disorders of the central and peripheral nervous systems, including trauma, epilepsy, stroke, Huntington disease, amyotrophic lateral sclerosis,and AIDS dementia, none have yet been applied to the treatment of glaucoma. A prospective, placebo-controlled, multi-institutional trial of memantine is underway. One would not expect the treatment modalities that form the bases of nonpharmaceutical, traditional medical systems to be used to lower IOP. Glaucoma was unknown when these medicinal treatments were developed over the centuries. Their primary use is in improving the cardiovascular and immune systems and in what is now called neuro-protection. Rather than single compounds that target a specific receptor and have demarcated side effects in other systems, plant products are a blend of many compounds and, according to those most versed in them, they achieve a balanced therapy, helping in specific symptomatic complexes while reducing side effects through ameliorating effects in other areas. It is not insignificant that, now that the rain forests are rapidly dwindling, together with their inhabitants and the knowledge of medicinal plants (especially in South America), the pharmaceutical companies are spending large amounts of money in a sudden, almost frantic attempt to gather the knowledge about rainforest plants before all has been completely lost. Proof of effects clinically in a chronic disease such as glaucoma remains largely lacking, and controlled trials are unlikely to be initiated, except perhaps through the National Institutes of Health, because these compounds have been in the public domain for many years. Perhaps those as yet unknown or un-recorded are patentable and perhaps these include drugs known only to small surviving communities of hunter-gatherers, which explains the pharmaceutical interest in these areas. When more accurate and rapid means of assessment of progression of glaucomatous damage than perimetry and optic nerve head photography are eventually developed and trials can be reduced in time, number of subjects, or even the use of nonhuman subjects for the bulk of studies, studies could be done for verification of effect of various compounds and also comparative studies. At the present time, GBE is the best documented of all the complementary medicinal agents and seems to have the greatest potential value. Ginkgo biloba extract has numerous properties that theoretically should be beneficial in treating non-IOP-dependent mechanisms in glaucoma. Its multi-ple beneficial actions, including increased ocular blood flow, antioxidant activity, platelet activating factor inhibitory activity, nitric oxide inhibition, and neuroprotective activity, combine to suggest that GBE could prove to be of major therapeutic value in the treatment of glaucoma.