Marc Grossman, OD, LAc

This article will help you make sensible, researched, and clinically based decisions to support optic nerve health with recommendations that include Western herbs, nutritional supplements, Chinese medicine, and additional therapies. You will learn about the underlying causes of glaucoma and be given tools and techniques to develop eye health strategies.

The primary goal of this article is to offer a practical approach, based on the underlying philosophy that emphasizes prevention and support. In doing so, we celebrate the healing power within all of us and the mind/body’s inherent potential for self-healing.

What Is Glaucoma?

Glaucoma is a symptom-free condition that is thought to be caused by damage to the optic nerve, which robs the patient of peripheral vision and can cause blindness. It is often referred to as the “silent thief.” More than three million people in the United States have glaucoma, 2.7 million people of whom have the most common form, open-angle glaucoma. The number is expected to increase to over four million by 2030. African Americans have the highest prevalence rate (3.4%), followed by other races (2.1%), whites (1.7%), and Hispanics (1.5%).¹

Glaucoma can be difficult to detect without a regular eye exam until a significant amount of vision is lost. The reason it is so dangerous is that most people with glaucoma have no symptoms. Many feel no pain, and most have 20/20 visual acuity, although possibly only straight-ahead vision. But left untreated, glaucoma can slowly steal your peripheral vision until you think you are peering through a tunnel (at best) or until you go blind (at worst). Most frightening, 70% of the vision lost to glaucoma occurs before diagnosis. Glaucoma may be due to the result of the loss of retinal ganglion cells and axons (nerve cells that pass along information) in the optic nerve and retina.² Thinning of the optic nerve may occur as well.

Neurodegeneration

Researchers now view glaucoma as a disease of the brain (a neurodegenerative disease) rather than simply an eye disease. Recent research has shown that the complex connection between the eye and the brain is an important key to the disease. The retina and optic nerve are both made up of brain tissue and are part of the brain. Glaucoma shares a number of features with degenerative brain diseases such as Alzheimer’s, Parkinson’s, and Lou Gehrig’s disease. In these diseases, age and family history are major risk factors, and specific areas of the brain are damaged over time.

In glaucoma, changes occur in the back of the eyes. The optic nerve continues to be a focus for researching the underlying causes of glaucoma. Whether due to mechanical trauma, decreased blood flow, or other causes, optic nerve axon injury causes changes in retinal ganglion cells, eventually resulting in cell death. Researchers have observed that specific areas of injured optic nerve axons and retinal ganglion cell loss match the peripheral vision damage from glaucoma.³

Neuroinflammation

Glaucoma, especially if acute, may be largely an inflammatory condition. Researchers believe that high intraocular pressure triggers an inflammatory response.⁴ In experiments, inflammation occurs in the central nervous system and at early stages of glaucoma. Inhibiting the process through which inflammation develops appears to protect the neurons from damage.⁴ Investigations of the precise role of neuroinflammation in causing glaucoma are on-going. Cells known as microglia behave like sensors to damage the nervous system and play a role in the inflammatory response. The process contributes to beta-amyloid accumulations, implicated in Alzheimer’s disease. Similarly, the eye, actually part of the brain, also accumulates beta-amyloid in the retina and optic nerve. Microglia activity and the inflammatory response are linked to protein clumping and nerve cell degeneration.⁵

Oxidative Stress

Increased oxidative stress is a risk factor. Antioxidant drugs and nutrients that reduce enzymes involved in oxidation are reported to be helpful in animals with glaucoma. Although targeting intraocular pressure (IOP) has been a prime therapy, researchers are increasingly looking to antioxidants to target oxidative stress.⁶ Damage to DNA in the tissue layers that regulate aqueous humor outflow is linked to oxidative damage, damage to neurons, and to the optic nerve.^7,8

Causes and Risk Factors

Genetics. There is a strong genetic correlation related to the onset of glaucoma.^9-12

High blood pressure. Although high blood pressure is not a direct cause of glaucoma, many studies have found it to be related.^10,13 In a 2011 study, researchers examined medical records of over two million people older than 40 who were enrolled in a US managed care network. Those with hypertension had a 17% increased risk.¹⁴

Hypertension may be implicated because high blood pressure can result from poor circulation. Poor circulation can also lead to a compromised delivery of nutrients to the eyes, possibly resulting in poor eye drainage, leading to an increase in ocular pressure. Poor circulation also can reduce the supply of critical nutrients to the optic nerve. Perhaps this is why glaucoma can result in vision loss at any level of eye pressure if the optic nerve is weak, due to poor circulation and lack of oxygen and essential nutrients.

Damage to blood vessels. Increased eye pressure can be caused by endothelial dysfunction and vascular structural changes. This can substantially alter blood flow within the tissues and elevate IOP, leading eventually to open-angle glaucoma.¹⁵ Vascular changes, such as low blood pressure, and vascular obstruction (poor circulation), have been linked to glaucoma.^16,17

Homocysteine. High homocysteine levels have been identified as a risk factor for open-angle glaucoma.^18,19 Other studies link high levels of homocysteine to the onset of pseudoexfoliation glaucoma.^20-22

Diabetes. Research has shown that glaucoma is closely related to diabetes, indicating a link to circulation and possibly inflammation. Examination of medical records of over 2 million people older than 40 found a 35% increased risk for open-angle glaucoma in people with diabetes.¹⁴

Thyroid disease. According to the CDC’s survey of 12,376 participants, an association has been drawn between thyroid disease and glaucoma. Researchers found that the prevalence of glaucoma was almost double in people with thyroid problems versus those without thyroid problems.²³

Helicobacter pylori. Medical researchers believe that H. pylori, which is the cause of many cases of stomach ulcers, may be implicated in a number of non-digestive conditions. These conditions include cardiovascular disorders, cerebrovascular disorders (blood circulation in the brain), and vascular dysfunctions. This organism may be involved in the pathology of the eye, specifically glaucoma. Meta-analysis suggested a statistically significant association between H. pylori infection and open-angle glaucoma,¹⁰ uveitis, and central serous maculopathy.

Drugs and medications. Non-steroidal anti-inflammatory drugs (NSAIDs) may interfere with effectiveness of IOP-lowering medications such as latanoprost.²⁴ Ongoing use of corticosteroids such as prednisone to reduce inflammation could increase IOP.²⁵ Topiramate (Topamax) can increase IOP and cause acute glaucoma, as well as medications prescribed for depression, Parkinson’s disease, and allergies. Such medications can cause the pupil to dilate, resulting in a smaller drainage angle of aqueous fluid.²⁶