There are several contributing factors that lead to us facing a dilemma in our treatment of normaltension glaucoma (NTG) patients.
It is known that at least a third of our glaucoma patients, both in Europe and the US, have normal pressures but currently
treatment still involves lowering intraocular pressure (IOP), which is possible to about 30% with surgery only. Even with
this reduction in IOP there is still a large amount of patients progressing.1
Additionally, normal methods of treatment of glaucoma patients who have elevated IOP, such as monitoring and preventing nocturnal
dips of systemic blood pressure doesn't help in NTG patients as most have low blood pressures. Even though we have had the
first indications that neuroprotection beyond IOP reduction is now possible there are too many allergic reactions with Brimonidine,2 so there is a need for real neuroprotection.
Natural compounds: An option
Our NTG patients have life expectancies that almost forbid a life-long treatment with Calcium antagonists. But natural compounds
could be one choice. In 2010, the World Glaucoma Association came up with the following consensus points
- Plant extracts have been used medicinally throughout history. Every society has used plants medicinally.
- Our modern pharmacopoeia of drugs were originally synthesized from plants used medicinally.
- Chinese traditional medicine (and Ayurveda) in their written forms date back 5000 years.
- It was only in the 20th century, with the advent of single molecule products synthesized and patented by pharmaceutical companies
and US medical school philosophies that other non-pharmaceutical traditional medications came under attack, leading often
to their being ridiculed and held in contempt.
- Many available natural compounds used as 'nonpharmaceutical therapy' have been reported to show beneficial effects on circulation,
the immune system, and neuroprotective activities in vitro and in vivo.
- The mechanism of action of neuroprotection most common to natural compounds is antioxidant/free radical scavenging activity.
However, many other actions are present and some extracts, such as Gingko biloba and Curcumin have widespread activity on
a number of enzyme systems.
- Curcumin reportedly modifies expression of enzymes relating to excitotoxicity, apoptosis, inflammation, lipid peroxidation,
or immune stimulation.
There are currently 33 NIH-sponsored trials involving Curcumin.
Curcumin
Figure 1: Chemical structure of curcumin.
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Curcumin (Figure 1) is a yellow colouring agent present in the commonly used spice, turmeric (cucuma longa), which has been
used in Indian cusine to add colour and as a preservative, and also in traditional medicine to treat various common diseases
(TCM and Ayurveda).
Studies of Curcumin have increased exponentially in recent years and over 2000 papers have been published since 2000. These
studies demonstrated that Curcumin has antioxidant, antibacterial, antiviral, antifungal, antiinflammatory and antiproliferative
as well as proapoptotic effects. Potential therapeutic effects of this compound on various diseases, including neurodegenerative,
cardiovascular, pulmonary, metabolic or immunerelated diseases, malignancies and infectious diseases, including AIDS, have
been suggested. The biology of the effects of Curcumin has been under intensive study and curcumin is now known to have numerous
molecular targets. Diseases for which there are ongoing clinical trials with Curcumin include Alzheimer's disease (AD), psoriasis
vulgaris, multiple myeloma, pancreatic cancer, familial adenomatous polyposis, and sporadic adenomatous polyps of the colon.3
