What is Glaucoma?

Glaucoma is a common eye disease that involves damage to the nerves within the eye leading to blindness. In 2020, the CDC had reported an estimation of about 3 million Americans with diagnosed glaucoma with the expectation for the numbers to increase. Glaucoma is recognized as the second leading cause of blindness in the world There are two types of glaucoma, open-angle and closed-angle glaucoma. The “open” and “closed” angle refers to the position of the iris altering the flow of fluid within the eye.

What are the differences between open-angle and closed-angle glaucoma?

In a normal healthy eye, a fluid called the “aqueous humor” circulates and flows throughout the front of the eye delivering important nutrients to the cells within the eye. The muscle that controls the iris produces this fluid allowing it to flow through the pupil and eventually drains through an opening within the outer part of the eye. When that drainage system fails, the continuous production of fluid may slowly build pressure within the eye. As the pressure within the eye increases, the surrounding tissues and nerves that also reside within the eye may become damaged.

Over 90% of all glaucoma cases in the US are open-angle glaucoma In open-angle glaucoma, the drainage system itself may be blocked, resulting in a slow increase in pressure. As pressure builds, the nerve residing in the back of the eye, called the optic nerve, may become pinched leading to damage or death of cells within the eye. This disease may be difficult to diagnose as open-angle glaucoma is usually a slow progressive disease. The only way to diagnose this disease is to assess the size and color of the optic nerve in the back of the eye indicating the nerve’s health. Treatment of this condition usually includes decreasing pressure within the eye by use of blood-pressure lowering eye drops, most commonly known as “beta-blockers”.

In closed-angle glaucoma, the iris is positioned in a way that blocks the flow of fluid to the front part of the eye. This condition usually presents itself quickly and can cause severe symptoms such as headache, nausea, vomiting, and vision loss within a couple hours. The only treatment for this dangerous condition is surgery.

Open-angle glaucoma

Closed-angle glaucoma









Am I at risk for glaucoma?

It is important to know what makes you at higher risk for developing glaucoma to get screened appropriately. According to the American Academy of Family Physicians (AAFP), the following may be risk factors:

  • Those over the age of 40 of African descent
  • Those over the age of 65 of European descent
  • Family history of glaucoma
  • History of diabetes
  • History of near sightedness
  • Elevated pressure within the eye
  • Changes in peripheral vision
  • Differences in optic nerve health between both eyes

The American Academy of Ophthalmology recommends a baseline screening with an eye doctor for those aged 40 and above There is no recommended set schedule for glaucoma screening for those over the age of 40, but the United States Preventative Services Taskforce recommends that a screening schedule be made with your eye doctor to assess risk factors and create a personalized screening plan. If you experience any changes vision, blind spots, severe forehead pain, redness of the eye, headache, nausea, or vomiting, contact your eye doctor as this may be an indicator of glaucoma development

The best way to reduce your risk for glaucoma is to maintain a healthy blood pressure. Activities to help maintain a healthy blood-pressure are daily exercises, maintaining a healthy weight, low-salt diets, and avoiding smoking It is important to stay up to date with your eye doctor and discuss ways to reduce your risk of developing glaucoma. Being able to modify the everyday choices you make can have beneficial results for the health of your eyes as well as prevention of many other medical conditions!

Prepared by Kelsey Tootill, PharmD Candidate 2024


  1. Centers for Disease Control and Prevention. (2020, November 24). Don’t let glaucoma steal your sight! Centers for Disease Control and Prevention. https://www.cdc.gov/visionhealth/resources/features/glaucoma-awareness.html#:~:text=Open%2Dangle%20glaucoma%20does%20not,avoid%20vision%20loss%20from%20glaucoma
  2. Distelhorst, J. S., & Hughes, G. M. (2003, May 1). Open-angle glaucoma. American Family Physician. https://www.aafp.org/pubs/afp/issues/2003/0501/p1937.html
  1. Eye Institute of Houston. (2020, March 23). When is a glaucoma screening necessary?. Eye Institute of Houston. https://www.eyeinstituteofhouston.com/when-is-a-glaucoma-screening-necessary/
  2. Sprabary, A. (2019, February 27). How often should you get your eyes checked?. All About Vision. https://www.allaboutvision.com/eye-exam/cost-and-how-often/
  3. Boyd, K. (2023, January 19). What is glaucoma? symptoms, causes, diagnosis, treatment. American Academy of Ophthalmology. https://www.aao.org/eye-health/diseases/what-is-glaucoma
  4. “Glaucoma Screening.” EyeWiki, 3 Feb. 2022, eyewiki.aao.org/Glaucoma_Screening#cite_note-uspstf3-3.