Glaucoma and blood pressure are closely related. In fact, both high blood pressure and low blood pressure have been associated with an increased risk of glaucoma, a disease that damages the optic nerve. This happens as fluid builds up and adds pressure inside the eye. More than three million Americans have glaucoma, but half of them don’t know they have it, says the Glaucoma Research Foundation.
This leading cause of blindness has no cure, but eye drops and oral medications can be prescribed to treat mild cases. However, glaucoma surgery may be the best course of action in more serious cases in order to lower eye pressure, and prevent or slow down damage to the optic nerve. It’s best to consult with your ophthalmologist at the first sign of glaucoma.
Let’s talk about the relationship between glaucoma and blood pressure.
Relationship Between BP and Glaucoma Risk
Very high blood pressure isn’t good for glaucoma, as it may raise eye pressure. On the other side of the coin, moderate to very low blood pressure can also pose a problem, as the optic nerve must receive enough blood flow.
Elevated eye pressure (AKA intraocular pressure) is the primary risk factor for glaucoma. There’s growing evidence showing that factors can predispose someone to glaucoma damage, including circulation to the eye and optic nerve. Non-traditional risk factors include low blood pressure or perfusion pressure, which is the amount of pressure it takes to push blood through the blood vessels in one specific area.
Traditional risk factors for glaucoma include high eye pressure, age, family history, and ethnicity, with clear evidence showing the risk of glaucoma goes up with higher eye pressure. The only risk factor above that your doctor can treat for is eye pressure.
But it’s important to note that high eye pressure on its own does not cause glaucoma. Most people with high eye pressure don’t have, and may never get, glaucoma. Some studies have shown that up to 40 percent of people who develop glaucoma have normal eye pressures. Sometimes, even in those who have glaucoma and elevated eye pressure, it’s within the normal range in about a third of the cases.
In a nutshell, eye pressure is indeed important in glaucoma, but it alone can’t determine why glaucoma develops in all patients.
Glaucoma: Other Risk Factors
Other risk factors for glaucoma must then be analyzed to get a clearer picture. Factors related to blood flow to the eye are at the top of the list. Ocular perfusion pressure in particular poses a strong risk factor for glaucoma. Again, this refers to the relationship between eye and blood pressure.
When blood pressure is too low and eye pressure is elevated, it’s challenging for blood to get into the eye to deliver oxygen and nutrients, as well as to get rid of waste. But even in those with normal eye pressure, they may have naturally-low blood pressure (or as a result of treatment) to keep adequate blood flow from reaching the eye.
Most people can automatically adapt to changes in blood pressure in order to maintain adequate circulation to critical systems such as the brain and eyes. But others simply lack the ability to adjust circulation, leading to eye tissue damage over time.
Some evidence shows that lowering the eye pressure can help treat glaucoma, but not enough data exists to support an increase in blood pressure for all glaucoma patients.
Because the link can be tenuous, it’s imperative to stay on top of your vision care visits and keep an open dialogue with your doctor.
Book Your Glaucoma Consultation With Broberg Eye Care
To learn more about what to expect with glaucoma surgery or to ask about glaucoma and blood pressure risks, schedule an appointment online or call us at (512) 447-6096.