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Glaucoma is the second leading cause of irreversible blindness worldwide. The disease affects about 5 million Americans, mostly over age 40. Distressingly, many of these individuals are unaware of their affliction until long after the optic nerve has already been permanently damaged.
The term “glaucoma” refers to a group of similar conditions that damage the retina and optic nerve, leading to visual impairment. Glaucoma is sometimes called a “silent thief” because it slowly robs its victims of peripheral vision, which can go unnoticed until the loss becomes significant enough to interfere with everyday life.
Although glaucoma-related vision loss is not reversible, the progression of the disease can nearly always be slowed or halted. When diagnosed and treated early, it seldom leads to blindness.
Prescription medications and surgery can control the clinical manifestations, but the most commonly prescribed drugs carry unpleasant side effects, while there are risks associated with surgery.
Fortunately, recent scientific studies have illuminated natural strategies to help attenuate the progression of glaucoma. Investigations have shown that a combination of plant-based interventions derived from French maritime pine bark and bilberry target one of the most common underlying problems with glaucoma: increased pressure in the front of the eye, a condition known as elevated intraocular pressure (IOP).
Human studies reveal that these natural compounds complement conventional glaucoma medications as well, acting synergistically to optimize IOP.
Moreover, conventional therapies do little to address a major contributor to visual impairment in glaucoma—mitochondrial dysfunction.2,3 Coenzyme Q10 and pyrroloquinoline quinone (PQQ) are two powerful mitochondrial protectants that may play a considerable, yet unappreciated role in maintaining visual acuity for glaucoma patients.
After reading this Life Extension protocol, you will understand how glaucoma emerges and discover that making lifestyle changes to control risk factors can lessen the risk of glaucoma development and progression. You also will learn about exciting findings related to a number of natural compounds with the ability to target multiple mechanisms underlying the progression of glaucoma.
Back of the Eye
The eye is a spherical structure. It is connected at its rear pole to the brain via the optic nerve. The optic nerve is a fibrous tube containing over one million horizontally running nerve fibers (axons), each one originating from a type of retinal cell called a ganglion cell.
The retina is composed of a thin sheet of cells (and related structures) that form the back wall of the eye. Its primary role is to capture light and transform it into electrical signals. The signals are transmitted to the brain by the optic nerve, where they are interpreted as the objects we “see.”
Ganglion cell axons are responsible for transmitting these electrical signals. The axons spread out across the retina to converge at the optic disc, the point of origin of the optic nerve. The optic disc is where damage from glaucoma is typically detected by an eye exam.
Front of the Eye
When we look at our eyes in the mirror, we see four main features of the front of the eyeball: the white sclera, the black pupil, the colored iris, and the dome-shaped cornea overlaying the iris and pupil. In most cases of glaucoma, the trouble lies immediately behind the cornea in the outflow of a fluid called aqueous humor (or aqueous fluid). Normally, aqueous humor flows from behind the iris (posterior chamber), where it is formed, to the front of the iris (anterior chamber) where it drains through the trabecular meshwork into Schlemm's canal and ultimately into the blood circulation (Figure 2). Aqueous humor should not be confused with tears, which are formed outside the eye.
Types of Glaucoma
There are two major forms of glaucoma: open angle glaucoma and angle-closure glaucoma. About 90% of cases of glaucoma are primary open angle glaucoma (POAG). The majority of others are angle-closure glaucoma.
Less common forms of glaucoma include congenital glaucoma, which tends to run in families and is present at birth; normal tension glaucoma; pigmentary glaucoma; pseudoexfoliative glaucoma; traumatic glaucoma; neovascular glaucoma; and iridocorneal endothelial syndrome.
In the last several years, glaucoma has come to be described as a “neurodegenerative disease,” because it shares features with several brain disorders including Alzheimer's disease, amyotrophic lateral sclerosis (Lou Gehrig's disease), and Parkinson's disease.
Signs and Symptoms of Glaucoma
Signs and symptoms of glaucoma differ depending upon the type of glaucoma. Most patients do not have any symptoms in the disease's early stages. Others may experience severe pain and rapidly compromised vision. Even without symptoms, people with glaucoma are vulnerable to a loss of peripheral vision, followed by reductions in central vision and blindness. (Symptoms should always be reported to the examining ophthalmologist or optometrist.)
- Most people with open angle glaucoma have no symptoms until they notice a loss of peripheral vision. The vision loss can be slowly progressive, leading to tunnel vision and finally blindness.
- Closed angle glaucoma is an acute condition (meaning it comes on quickly with a rapid rise in IOP) and is often associated with severe eye pain. Angle closure glaucoma is a medical emergency and must be treated quickly to prevent vision loss. Symptoms may include extreme eye pain, headaches, blurred vision, red eyes, halos around lights, tender and firm eyes, and nausea and vomiting. An eye exam usually shows a shallow anterior chamber and mildly dilated pupils, sometimes drug related.
- Congenital glaucoma can be marked by excess tearing of the eyes (usually associated with a malformed tear duct drainage system), iris abnormalities, extreme sensitivity to light, and a large and hazy cornea.
Risk Factors for Glaucoma
There are many risk factors for glaucoma, ranging from factors you cannot control (genetic abnormalities and age) to lifestyle factors. Some of the known risk factors for glaucoma include:
Intraocular Pressure (IOP)
Normal IOP is between 10 millimeters mercury (mm HG) and 20 mm Hg. Higher-than-normal IOP is perhaps the most significant risk factor for glaucoma. It is important to distinguish between “intraocular pressure” and “blood pressure”; they are not synonymous. Intraocular pressure (IOP) refers to the pressure caused by the aqueous humor secreted by the ciliary body, while blood pressure refers to the pressure exerted by the blood on the blood vessel (artery) wall.
Age
People older than 60 are more likely to develop glaucoma. For some ethnic groups, risk begins at an earlier age.
Ethnicity
African-Americans have the highest risk for glaucoma in the United States (12%). Among Asian Americans and U.S. Hispanics, the glaucoma risk is 6.5%.
Medical Conditions
Glaucoma is especially closely related to diabetes and high blood pressure. In a 2011 study, researchers examined medical records of over 2 million people older than 40 who were enrolled in a U.S. managed care network. The records revealed a 35% increased risk in people with diabetes of developing open angle glaucoma and a 17% increased risk in those with hypertension. Both conditions together raised the risk to 48%.
An association has also been drawn between thyroid disease and glaucoma, according to a study of 12,376 participants from the CDC's 2002 National Health Interview Survey. Researchers found that the prevalence of glaucoma was almost double in people with thyroid problems versus those without thyroid problems.
Other Eye Conditions
Based on a study of 2,650 patients where 579 patients (21.84%) had secondary glaucoma, eye-related causes, in order of frequency, were post vitrectomy surgery, eye trauma, corneal pathology, aphakia, neovascular glaucoma, pseudophakia, and uveitis. There were also cases secondary to tumor, myopia, pseudoexfoliation syndrome, retinopathy of prematurity, aniridia, iridocorneal endothelial syndrome, and chemical injury to the eye.
Corticosteroids
Glaucoma risk is raised by prolonged use of corticosteroids, including corticosteroid-containing eye drops for reducing eye inflammation and inhalers for treating asthma.
Lack of Physical Activity
p>Research suggests an association between low levels of physical activity and low ocular perfusion pressure (OPP), a risk factor for glaucoma. OPP is a calculation derived from IOP and blood pressure.
Genetics
Having a family history of glaucoma is a well-established risk factor, and the role of genetics in glaucoma continues to receive scientific scrutiny. In the late 1990s, researchers began identifying glaucoma gene mutations, including several in a gene that encodes for the protein TIGR found in the trabecular meshwork. They discovered the mutations by studying families with POAG. The mutation occurred in 4.4% of these patients, compared to 0.3% of the general population.
Since then, several other genes (eg, MYOC, OPTN) have been associated with POAG. Among the most recently noted is ADAMTS10, which was discovered in a unique population of beagles with glaucoma.
Another gene linked to glaucoma is CYP1B1. In some populations, CYP1B1 mutations are found in over half of all cases of congenital glaucoma.
Researchers expect to find many more genes and other events involved in the initiation and progression of glaucoma. An important aspect will be to identify people with genetic and other risk factors and to counsel them about ways to reduce the likelihood of developing glaucoma.
Lastly, other drugs besides steroids can raise the risk of glaucoma, especially of angle-closure glaucoma. Categories of drugs known as anticholinergics, and adrenergics are the most common. Sulfa drugs, antihistamines, and decongestants can also cause problems. And several anti-cancer drugs can increase the risk of open angle glaucoma. Because the cause of the glaucoma is linked to the particular drug usage, the first line of treatment is to discontinue the drug. Note: If you have glaucoma, make sure to inform your healthcare provider and pharmacist. They should know what drugs to avoid.