Vision changes are a normal part of aging for many people. Two of the most common conditions that affect the eyes later in life are cataracts and glaucoma. While they are distinct problems with different effects on your sight, they can sometimes be related. Understanding the connection between them is a key part of protecting your long-term eye health.
A cataract is a clouding of the eye’s natural lens, which sits behind the colored part of your eye, the iris. Glaucoma is a disease that damages the optic nerve, the vital link between your eye and your brain. The question many people have is whether one of these conditions can cause the other. In certain situations, a cataract can indeed lead to an increase in eye pressure, creating a form of glaucoma.
What Are Cataracts?
To understand the connection, it’s useful to first review what a cataract is. Your eye’s lens is normally clear. It works much like a camera lens, focusing light onto the back of your eye so you can see things clearly at different distances.
Over time, the proteins inside this lens can begin to break down and clump together. This clumping creates a cloudy area, or a cataract. As the cataract grows larger, it blocks more light and makes your vision blurry, hazy, or less colorful. This process usually happens slowly over many years.
Most cataracts are a result of the natural aging process. They are very common, affecting a large portion of the population over the age of 60. While cataracts can significantly impair vision, the cloudy lens can be removed and replaced with a clear, artificial one through a very common and safe surgical procedure.
What Is Glaucoma?
Glaucoma works differently. It is not about the lens but about the health of your optic nerve. This nerve is like a data cable sending visual information from your eye to your brain. When the nerve fibers become damaged, they can no longer send complete signals. This results in the loss of vision, typically starting with your peripheral, or side, vision.
One of the main risk factors for glaucoma is high pressure inside the eye. This pressure is called intraocular pressure, or IOP. Your eye constantly produces a clear fluid called aqueous humor that circulates in the front part of the eye. This fluid nourishes the eye and then flows out through a drainage system.
If this drainage system becomes blocked or works poorly, the fluid cannot exit properly. The backup of fluid causes the pressure inside the eye to rise. This elevated pressure pushes against the delicate optic nerve, causing damage over time.
How Can a Cataract Cause Glaucoma?
The connection between cataracts and glaucoma happens when the cataract itself interferes with the eye’s internal structures, particularly the fluid drainage system. This does not happen with all cataracts. The risk arises when a cataract becomes very advanced or mature. There are two primary ways this can occur.
One way is through a process called phacomorphic glaucoma. The term ‘phaco’ refers to the lens of the eye. As a cataract develops, the lens not only becomes cloudy but can also get thicker and larger. In a very advanced cataract, this enlarged lens can push the iris forward. This movement can narrow the angle between the iris and the cornea, which is where the eye’s drainage system is located.
Think of it like a piece of furniture being pushed against a door. The enlarged lens physically crowds the front of the eye, pinching the drainage angle shut. When this happens, the aqueous humor fluid cannot escape, and eye pressure rises sharply. This can cause a sudden and serious form of glaucoma.
A second way the connection can form is through phacolytic glaucoma. This condition can happen when a cataract is hyper-mature, meaning it is extremely advanced. In this state, the cataract’s outer capsule can begin to leak protein particles into the fluid inside the eye.
These protein particles can then flow into the eye’s drainage system. The particles are large enough to clog the drain, like debris blocking a sink. This blockage prevents fluid from exiting the eye effectively, leading to a gradual or sometimes rapid increase in intraocular pressure. This increased pressure can damage the optic nerve and cause glaucoma.
Does Every Cataract Lead to Glaucoma?
It is important to know that the vast majority of cataracts do not cause glaucoma. These specific types of glaucoma are linked almost exclusively to cataracts that have been left untreated for a very long time and have become exceptionally dense and large.
In the early and intermediate stages of development, a cataract typically has no effect on eye pressure. This is why regular eye examinations are so valuable. An eye doctor can monitor your cataract’s progression. They can see if it is growing in a way that might threaten to block the eye’s drainage system. By identifying the risk early, treatment can be recommended before a pressure problem develops.
How Is the Problem Diagnosed?
If your eye doctor suspects a connection between a cataract and high eye pressure, they will perform several tests during a complete eye examination. These evaluations are straightforward and give your doctor a clear picture of your eye’s health.
- Slit-Lamp Exam: Using a special microscope, your doctor can look at your eye’s lens in high detail. This allows them to see how large, dense, and cloudy your cataract is. They can also assess the depth of the front chamber of your eye to see if it is becoming crowded.
- Tonometry: This is the standard test to measure your intraocular pressure. It can be done with a gentle puff of air or a tool that briefly touches the surface of your eye after it has been numbed with drops.
- Gonioscopy: This test gives your doctor a direct view of the drainage angle inside your eye. A special contact lens is placed on the eye, allowing the doctor to determine if the angle is open, narrowed, or closed. This is the best way to see if a bulky cataract is physically blocking the drain.
- Optic Nerve Examination: Your pupils will be widened with eye drops. This allows your doctor to look directly at your optic nerve at the back of your eye. They will check for any signs of damage that might indicate glaucoma.
What Is the Best Treatment Approach?
When a cataract is causing high eye pressure, the most direct and effective treatment is to address the source of the problem: the cataract itself.
Cataract surgery is the primary treatment. During this procedure, the large, cloudy lens is removed from the eye. It is replaced with a thin, clear, artificial lens. Removing the bulky cataract has an immediate effect. It creates more space in the front of the eye, which helps the drainage angle to open up again. This can resolve the pressure problem in cases of phacomorphic glaucoma.
In cases of phacolytic glaucoma, removing the cataract stops the leakage of proteins. Once the source of the clogging material is gone, the drainage system can often clear itself, allowing eye pressure to return to a normal level.
In fact, cataract surgery is often found to lower eye pressure even in people who do not have this specific problem. The new artificial lens is much thinner than the natural lens, which can improve the outflow of fluid permanently. For this reason, sometimes your doctor may recommend cataract surgery as a way to help manage both the cataract and the eye pressure at the same time.
Ready to take the next step toward a clearer vision? Schedule a consultation with SuraVision today to discuss your options and learn more about the Cataract surgery process. Call us at 713-730-2020 or book your appointment online!