Glaucoma is one of the leading causes of vision loss in the US, with more than 2.2 million Americans currently living with a glaucoma diagnosis. The National Eye Institute estimates that as many as 2 million additional Americans are presently affected by glaucoma but are unaware of it. It’s the leading cause of irreversible blindness and is known as the “silent blinder” because it presents no noticeable symptoms in its early stages.
While the causes of some types of glaucoma are still unknown, there are well-identified risk factors for the most common types. Addressing these risk factors early and getting regular eye exams are the best ways for individuals to reduce their risk of glaucoma-related vision loss.
In this article, we’ll look at what causes glaucoma and what steps you can take to reduce your risk of falling prey to this “silent blinder.”
What Is Glaucoma?
Glaucoma is a term used to describe several related conditions in which the optic nerve at the back of the eye suffers damage, causing a reduction in vision and, if left untreated, blindness. In the vast majority of cases – more than 95% – this damage results from increased pressure inside the eyeball (intra-ocular pressure, IOP), putting additional strain on the delicate nerve.
What Causes Glaucoma?
While not every case of glaucoma is associated with high IOP, and not everyone with elevated ocular pressure will eventually suffer the effects of glaucoma, the two conditions are closely related. Among the risk factors for glaucoma, increased ocular pressure is the only factor that can be addressed. The other risk factors are unchangeable:
- Race – Glaucoma is more prevalent in African- and Hispanic-Americans.
- Age – The risk of glaucoma increases after the age of 60.
- Family history – People who have family members, especially siblings, with glaucoma are more likely to develop the condition.
- Corneal thickness – Those with a thinner cornea are at a higher risk for glaucoma.
As IOP is the only risk factor that can be controlled, understanding what causes that pressure is critical to addressing it and reducing your risk for glaucoma.
Your eyes contain a complex network of channels, filters, and ducts that continually circulate fluid around and through the part of the eye contained by the cornea, the anterior chamber. This fluid, known as the aqueous humor, normally drains through a sponge-like tissue called the trabecular meshwork (TM) found around the base of the cornea.
In most glaucoma cases, something interferes with that drainage, and fluid backs up in the eye’s anterior chamber, putting pressure on the entire eyeball. The two main types of glaucoma, open-angle and angle-closure glaucoma, fall into this category.
By far the most common form, open-angle glaucoma is caused by damage to or inflammation of the trabecular meshwork, causing it to become obstructed or otherwise unable to provide adequate drainage of the eye’s anterior chamber.
Angle-closure glaucoma has a more rapid onset and can cause severe eye pain, blurred or narrowed vision, and halos or rainbows around lights. This glaucoma type is caused by the narrowing or even complete closure of the angle between the cornea and the iris, which houses the trabecular meshwork.
Open-Angle and Angle-Closure Treatments
Eye specialists can diagnose these types of glaucoma using a number of tests and tools, including:
- Tonometry: the measure of your eye’s internal pressure.
- Gonioscopy: the use of a special lens to directly observe the cornea and the eye’s drainage system.
- Pachymetry: the measurement of your corneal thickness.
If the signs of open-angle or angle-closure glaucoma are present, several treatments may be able to slow the disease’s progress and prolong or even preserve the patient’s eyesight:
- Medications exist to reduce the eyes’ rate of fluid production, reducing overall eye pressure.
- Other medications target the trabecular meshwork to reduce inflammation or otherwise encourage increased drainage.
- Traditional surgical procedures may create new openings to allow for the drainage of fluid or may implant a shunt to help the eye drain away fluid.
- Laser surgical procedures also exist to treat glaucoma.
- In some patients, cataract surgery (intraocular lens replacement) has been shown to reduce eye pressure, and the procedure may be used to slow the effects of glaucoma, as well.
Other Types of Glaucoma
While most glaucoma patients suffer from one of the two above types, other types of glaucoma exist, each with a unique set of risk factors, progression, and outlook:
- Low-tension glaucoma is a rare condition in which the optic nerve is damaged by something other than increased eye pressure.
- Congenital glaucoma occurs in infants when the drainage canals in the eye don’t develop properly during gestation.
- Inflammatory glaucoma (uveitic glaucoma) is caused by inflammatory disorders and autoimmune conditions.
- Neovascular glaucoma results from damage to the blood vessels in the eye, usually due to poorly managed diabetes or another vascular condition.
If you have diabetes, have a condition affecting your blood vessels, have a chronic inflammatory or autoimmune disorder, or have experienced a gradual loss of vision, particularly around the periphery of your vision, make sure to discuss this with your eye doctor during your next exam.
What Can I Do Now to Prevent Glaucoma?
While there’s no guaranteed way to prevent glaucoma, most cases can be detected and treated early enough to preserve most or all of your vision if you have regular eye exams. If you have any of the risk factors discussed above, you should see your eye doctor once a year. Share any concerns about glaucoma with them, and they can provide regular, consistent monitoring to keep you healthy.
If you don’t have any of the risk factors above, you should still schedule regular eye exams. While you may not need to see your eye doctor once a year, your eyes should be examined at least every other year. That way, your eye health will be continually monitored should you begin developing any warning signs without noticing any symptoms.
Don’t Let the “Silent Blinder” Catch Up to You. Call Eyesight Associates and Schedule a Vision-Saving Eye Exam Today!
Our eye specialists can perform tests to determine whether or not you’re at risk of glaucoma-related vision loss. Give us a call to learn more: 478-923-5872.