Glaucoma and Cataracts

University of California, San Francisco, UCSF Medical Center
Eye exam for glaucoma

This article provides answers to important questions regarding the relationship between glaucoma and cataracts, and discusses treatment options if you have both conditions.

Glaucoma and cataracts are two eye conditions that occur more frequently as we get older. A cataract is a clouding of the lens of the eye, which eventually causes impairment of normal daily activities such as driving. Cataracts are also the leading cause of blindness worldwide, but the condition is reversible, with a surgery called cataract extraction. Glaucoma, which is actually a group of diseases, is a leading cause of irreversible blindness worldwide. In glaucoma, the neurons that compose the optic nerve are damaged, and treatment at this time consists of lowering eye pressure through medications, laser, or surgery.

View a Video on Cataracts

View Video

Do Cataracts Cause Glaucoma?

Cataracts do not cause glaucoma per se, although there are certain rare forms (outside the scope of this discussion) in which the cataract is the causative factor of elevated eye pressure and damage to the optic nerve.

More commonly, a cataract can contribute to primary-angle closure, in which the eye’s drainage angle is more narrow than usual. Generally, the angle can be thought of as the angle between the iris and the cornea (see medical illustration below).

Anatomy of the Eye

Cataracts can play a role because as the lens becomes a cataract, it becomes cloudy and thickens, and the drainage angle can further narrow. Therefore, for some patients, it may make sense to remove the cataract as part of a treatment plan for glaucoma. Additionally, we now have strong evidence to suggest that cataract removal by itself can lower eye pressure by a few points.

Does Glaucoma Cause Cataracts?

Glaucoma itself does not cause cataracts, although there are certain situations in which cataracts are exacerbated by treatment for glaucoma. For example, glaucoma surgeries such as trabeculectomy or glaucoma drainage devices such as tube shunts, are known to modestly accelerate the rate of cataract formation. Sometimes the same situation that leads to glaucoma can result in cataracts. For example, topical steroids used to treat inflammatory conditions can result in steroid-induced glaucoma and steroid-induced cataract formation.

Can Cataracts and Glaucoma be Treated at the Same Time?

Trabeculectomy and tube shunt surgeries can be performed at the same time as cataract surgery, or as a standalone surgery. This is usually determined based on the patient’s situation and the surgeon’s preference.

Newer, minimally-invasive glaucoma surgeries (MIGS), are approved for use in conjunction with cataract surgery. One advantage of these MIGS is that they can be performed through the same small incision as the cataract surgery, and they generally entail less risk than trabeculectomy and tube shunt surgeries. The disadvantage is that, in general, the MIGS do not lower the eye pressure as much as trabeculectomy or glaucoma drainage device surgeries.


No matter what treatment choices are made, it is important to remember that glaucoma surgery should be prioritized if your glaucoma is not in good control with medications and laser. Cataract surgery is elective, and there is usually no harm in delaying the surgery.

One situation in which delaying a treatment is less advised is in patients with pseudoexfoliation syndrome and cataracts. In this syndrome, the cables (zonules) holding the lens in place are weak, thereby increasing the risks of cataract surgery. Thus it is sometimes advised to avoid delaying cataract surgery, as the lens becomes denser and more difficult to remove over time.

We have briefly discussed the various ways cataracts and glaucoma intersect. It is important to discuss your unique situation with your ophthalmologist so that you can understand how cataracts and glaucoma impact your eyes and vision.


This content was first posted on: June 12, 2017

The information provided here is a public service of the BrightFocus Foundation and should not in any way substitute for personalized advice of a qualified healthcare professional; it is not intended to constitute medical advice. Please consult your physician for personalized medical advice. BrightFocus Foundation does not endorse any medical product, therapy, or resources mentioned or listed in this article. All medications and supplements should only be taken under medical supervision. Also, although we make every effort to keep the medical information on our website updated, we cannot guarantee that the posted information reflects the most up-to-date research.

These articles do not imply an endorsement of BrightFocus by the author or their institution, nor do they imply an endorsement of the institution or author by BrightFocus.

Some of the content may be adapted from other sources, which will be clearly identified within the article.

More Like This

  • Two new medications hold great promise in lowering eye pressure by directly targeting the tissue that is diseased in glaucoma, the trabecular meshwork

    Two New Glaucoma Medications: Learn More

    Learn about two new medications that were approved by the FDA in late 2017, and why they are so exciting to patients and ophthalmologists alike.

    March 14, 2018
  • Secondary Glaucoma (Medications - Eye Disease - Trauma - Diabetes)

    Secondary Glaucoma

    Secondary glaucoma is a broad term that encompasses many types of glaucoma that are the result of certain medical conditions in the eye or the body.

    February 12, 2018
  • Searching on a computer for clinical trials
    Tips & How-Tos

    Is It a Match? Choosing a Clinical Trial That’s Right for You

    Are you thinking you may wish to participate in a clinical trial, but you aren’t sure how to get started? BrightFocus Foundation and Antidote – a third-party clinical trial matching service – have teamed up to make it easier to search for and find a clinical trial that is right for you.

    December 11, 2017

Don't miss out.
Receive research updates, inspiring stories, and expert advice
Keep me informed about: *
Please select at least one.
You must select at least one disease category.
Please enter your first name.
Please enter your last name.