They are the two leading causes of blindness. These two unique conditions are more likely to occur with aging and eye trauma.
Both conditions can be treated, especially when they are diagnosed in the early stages. By understanding the differences between glaucoma and cataracts, you can be prepared and proactive about your eye health.
About Glaucoma & Cataracts
|What Is It?||Glaucoma is a condition that involves a buildup of fluid in the eye, creating an increase in eye pressure or IOP (intraocular pressure). This occurs when there is too much fluid production or when the surrounding tissue doesn’t drain. High pressure damages the optic nerve, causing glaucoma.|
There are two main types of glaucoma. The most common is primary open-angle; the less common type is angle-closure. Angle closure-glaucoma is where the space that usually drains the fluid closes off. This can happen gradually or rapidly.
|Cataracts occur due to biochemical changes in protein structure in the eye’s lens. This produces cloudiness, creating vision problems. Vision can be corrected with cataract removal surgery.|
|Symptoms||With primary open-angle glaucoma (the most common type), there are no early symptoms — no early vision changes and no pain. |
The rarer type, angle closure-glaucoma, may have no early symptoms.
If eye pressure increases suddenly, symptoms can include:
-Eye pain and sharp pressure
-Intense headaches, nausea, or vomiting
-Extremely blurry vision
-Halos or rainbows around lights
|Seeing colors as faded or yellow|
Halos or glares around lights
Difficulty driving at night
Difficulty with reading and watching television
Frequently changing prescriptions
|Risk Factors||Not getting regular eye examsAge (more common in older individuals)Family history, race, and ethnicity (more common in African Americans, Hispanic Americans, and people of Asian descent)Medical conditions, such as diabetes, high blood pressure, heart disease, and sickle cell anemia|
Low blood pressure for of open-angle glaucoma (OAG)
Steroid use Eye injuries, such as sports-related injuries
|Age (more common in those 40+)Eye trauma or head trauma|
Past eye surgeries
Other eye diseases
|Causes||The eye is bathed in a fluid called aqueous humor, which flows into and drains out of the eye. This fluid keeps the eye pressure stable and balanced. |
If there is a buildup of fluid or the eye cannot drain properly, pressure rises, damaging the optic nerve. This can cause vision loss, and if untreated, blindness
|Natural biochemical changes of protein in the lens|
|Diagnosis||Early detection with regular eye exams||Early detection with regular eye exams|
|Treatment||Treatment options vary depending on the progression of glaucoma. Prescription eye drops are often prescribed to lower eye pressure. Oral medications may be used if eye drops don’t reduce eye pressure. |
Surgical procedures are used for further treatment to lower eye pressure. The main types of surgery are laser surgery, trabeculectomy, and MIGS.
Surgery is typically successful with long-term results. In the early stages, surgery can prevent and slow vision loss.
Unfortunately, damage caused by glaucoma is not reversible. Lost vision cannot be restored.
|Surgery is used to remove the clouded lens and replace it with an artificial lens.|
Age is a risk factor for both glaucoma and cataracts. The American Academy of Ophthalmology advises a baseline eye exam for both starting at age 40.
Which Is Worse: Cataract or Glaucoma?
Glaucoma is often considered more serious because it can require immediate medical attention. Additionally, if vision is impaired due to glaucoma, the lost vision cannot be restored.
In contrast, vision loss from a cataract is typically fully restored when the cataract is surgically removed.
People can have both glaucoma and cataracts at the same time or throughout the course of life.
Can Glaucoma Cause Cataracts or Vice Versa?
Glaucoma doesn’t cause cataracts, and cataracts don’t cause glaucoma, but the presence of one can increase the likelihood of the other. For example, certain glaucoma surgeries can increase the risk of developing cataracts.
Likewise, cataracts can increase your likelihood of developing glaucoma. According to the American Academy of Ophthalmology, if a cataract is very large, it may block the eye’s ability to drain fluid. This increase in pressure can lead to glaucoma.
Eye pressure usually decreases when the cataract is removed by surgery.
The Differences Between Glaucoma & Cataracts
Glaucoma damages the optic nerve, and it is the leading cause of vision loss.
According to the Glaucoma Research Foundation, in 2020, more than 30 million people were identified as having glaucoma. Approximately half of the United States patients have not been diagnosed. Worldwide, the number is estimated to be 80 million.
Glaucoma is six to eight times more common in African Americans. Hispanic Americans face a similar increased risk.
People of Asian descent are at increased risk for angle-closure and normal-tension glaucoma. People of Japanese descent have an increased risk for normal-tension glaucoma.
The keys to preventing vision loss and blindness from glaucoma are early detection, diagnosis, and treatment.
Cataracts are an eye condition where the lens of the eye is clouded. According to the National Eye Institute, the United States population with cataracts is expected to grow from 24.4 million to approximately 50 million by 2050.
The primary treatment is cataract surgery, which replaces the clouded lens with an artificial lens, or IOL. Some patients with astigmatism may opt to have cataract surgery and lens restructuring to enable them to reduce reliance on prescription eyewear. The goal of cataract surgery is clear vision.
Comprehensive regular eye exams can help you and your physician detect cataracts.
Similarities Between Glaucoma & Cataracts
Both cataracts and glaucoma are associated with vision loss. Both conditions are more common in people with diabetes.
While both cataracts and glaucoma can be surgically treated, surgery is not the initial treatment for glaucoma. Eye drops and other treatment methods are usually attempted first. Surgery is the only treatment for cataracts.
Can You Have Surgery for Both?
Yes, you can have surgery for both glaucoma and cataracts.
For glaucoma, surgery helps to reduce pressure on the optic nerve. The surgery involves creating pathways for excess fluid to drain. This may be done within the eye or with drainage shunts outside the eye. Surgery for glaucoma does not reverse vision loss.
According to the National Eye Institute, surgery for glaucoma typically involves three types of procedures based on the progression of the condition.
- Laser surgery: This type of glaucoma surgery helps to unblock the drainage canals.
- Filtering surgery: Also called trabeculectomy, this surgery creates an opening in the eye and removes some of the trabecula, the eye’s mesh-like network. A small tube or shunt is inserted to remove excess fluid.
- MIGS (minimally invasive glaucoma surgery): This surgery has a faster recovery time and fewer complications. It lowers eye pressure and may be combined with cataract removal.
Surgery for cataracts involves removing the clouded lens and gently inserting an artificial lens. Some forms of cataract removal may be combined with a surgical procedure to restructure the shape of the lens, resulting in being able to see with reduced dependence on eyewear.
The outcome of cataract surgery is a reversal of vision loss since the blurriness and clouded vision caused by the cataract are gone once it is removed. Improvements in vision are typically fast.
What Is Glaucoma? American Academy of Ophthalmology (AAO).
What Are Cataracts? American Academy of Ophthalmology (AAO).
The Pathophysiology and Treatment of Glaucoma. (August 2015). Journal of American Medical Association.
Do I Have Cataracts or Glaucoma? Glaucoma Research Foundation (GRF).
Glaucoma History and Risk Factors. (April–June 2017). Journal of Optometry.
Be Prepared: Understanding Glaucoma Risk Factors. Glaucoma Research Foundation (GRF).
Angle-Closure Glaucoma. Glaucoma Research Foundation (GRF).
Glaucoma Eyedrops. American Academy of Ophthalmology (AAO).
Cataract Data and Statistics. National Eye Institute (NEI).
Cataracts and Glaucoma. Glaucoma Research Foundation (GRF).
Last Updated June 8, 2022
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