Glaucoma

Certain types of glaucoma as well as surgery to treat glaucoma have been linked to the development of certain types of cataracts. In addition, we can develop secondary glaucoma as a complication of cataract surgery.

What is Glaucoma? Can Glaucoma Cause Cataracts?

Glaucoma is an eye disease that develops when the slow drainage of the aqueous humor through the eye's trabecular meshwork causes the build-up of pressure inside the eye. If left untreated, this build-up of intraocular pressure damages the optic nerve, causing blindness.

There are many types of glaucoma, though not all types are associated with the development of cataracts.

The most common type of glaucoma is chronic open-angle glaucoma. With this type of glaucoma, the angle between the iris and the cornea through which fluid drains from the eye's anterior chamber remains open, yet fluid still drains too slowly. This type of glaucoma is often painless in its early stages, but you are at increased risk if a relative has or had glaucoma.

Cataracts cannot be caused by chronic open-angle glaucoma.

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With acute closed-angle glaucoma, the angle through which fluid drains narrows rapidly, blocking drainage. When this happens, pressure inside the eye builds up quickly, hardening the eyeball and causing pain, blurred vision, and halos around lights.

Though halos around lights are also a symptom of cataracts, if you have glaucoma and see halos, you do not necessarily have a cataract. However, acute closed-angle glaucoma can lead to the development of a cataract. The longer the drainage of the aqueous humor is blocked, the more the flow of liquid in and out of the lens is disturbed, increasing the chance that the lens can develop a cataract.

While glaucoma is usually treated with medication, when medication does not work, your doctor may recommend surgery. Both conventional incision surgery, also known as filtering surgery, and cyclodestructive surgery have been known to cause cataracts to develop.(1) Any kind of trauma to the eye that causes inflammation, including surgery, can contribute to the formation of cataracts.

Can Cataracts Cause Glaucoma?

Sometimes, when a cataract is mature and begins to swell due to increased fluid content, the lens may contact the iris tightly and block the flow of aqueous humor through the angle of drainage. When the flow of aqueous humor is blocked, the pressure inside the eye rises and glaucoma develops.

In addition, intraocular pressure can sometimes be elevated during cataract surgery, causing secondary glaucoma. Secondary glaucoma is very uncommon after cataract surgery, but is usually temporary and easily treatable with glaucoma medications.

Things to Consider in Cataract Treatment

Glaucoma can make treating cataracts more complicated. Some of the older drugs used to treat glaucoma can affect the size of the pupil, which can make cataract surgery more challenging. If you have glaucoma and are about to undergo cataract surgery, be sure to ask your doctor about how one might affect the other.

For more information on glaucoma, visit the Glaucoma Research Foundation.