Glaucoma - Research

Research

• The Advanced Glaucoma Intervention Study is a large American National Eye Institute-sponsored study designed "to assess the long-range outcomes of sequences of interventions involving trabeculectomy and argon laser trabeculoplasty in eyes that have failed initial medical treatment for glaucoma". It recommends different treatments based on race.
• The Early Manifest Glaucoma Trial is another NEI study which found immediate treatment of people who have early-stage glaucoma can delay progression of the disease.
• The Ocular Hypertension Treatment Study, also an NEI study, found topical ocular hypotensive medication was effective in delaying or preventing onset of primary open-angle glaucoma (POAG) in individuals with elevated intraocular pressure (IOP). Although this does not imply all patients with borderline or elevated IOP should receive medication, clinicians should consider initiating treatment for individuals with ocular hypertension who are at moderate or high risk for developing POAG.
• The Blue Mountains Eye Study was the first large, population-based assessment of visual impairment and common eye diseases of a representative older Australian community sample. Risk factors for glaucoma and other eye disease were determined.

Natural compounds

Natural compounds of research interest in glaucoma prevention or treatment include: fish oil and omega-3 fatty acids, alpha lipoic acid, bilberries, vitamin E, cannabinoids, carnitine, coenzyme Q10, curcurmin, Salvia miltiorrhiza, dark chocolate, erythropoietin, folic acid, Ginkgo biloba, ginseng, L-glutathione, grape seed extract, green tea, magnesium, melatonin, methylcobalamin, N-acetyl-L cysteine, pycnogenols, resveratrol, quercetin and salt. However, most of these compounds have not demonstrated effectiveness in clinical trials. Magnesium, ginkgo, salt and fludrocortisone, are already used by some physicians. (Note: fludrocortisone is not a natural compound, but a steroid.)

Cannabis

Studies in the 1970s showed marijuana, when smoked or eaten, effectively lowers intraocular pressure by about 25%, as much as standard medications. In an effort to determine whether marijuana, or drugs derived from it, might be effective as a glaucoma treatment, the US National Eye Institute supported research studies from 1978 to 1984. These studies demonstrated some derivatives of marijuana lowered intraocular pressure when administered orally, intravenously, or by smoking, but not when topically applied to the eye.

In 2003, the American Academy of Ophthalmology released a position statement which said, "studies demonstrated that some derivatives of marijuana did result in lowering of IOP when administered orally, intravenously, or by smoking, but not when topically applied to the eye. The duration of the pressure-lowering effect is reported to be in the range of 3 to 4 hours".

However, the position paper qualified that statement by stating marijuana was not more effective than prescription medications, and "no scientific evidence has been found that demonstrates increased benefits and/or diminished risks of marijuana use to treat glaucoma compared with the wide variety of pharmaceutical agents now available."

The first patient in the United States federal government's Compassionate Investigational New Drug program, Robert Randall, was afflicted with glaucoma and had successfully fought charges of marijuana cultivation because it was deemed a medical necessity (U.S. v. Randall) in 1976.

5-HT_2A agonists

Peripherally selective 5-HT_2A agonists, such as the indazole derivative AL-34662, are currently under development and show significant promise in the treatment of glaucoma.