The Relationship Between Diabetes and Glaucoma

Diabetes and glaucoma are two common health conditions affecting millions of people worldwide. Both can significantly impact an individual’s quality of life.

Research studying the relationship between diabetes and glaucoma has yielded mixed results. We’ll look at why diabetes could be a glaucoma risk and then at scientific studies to see what kind of relationship exists.

What Is Glaucoma?

Glaucoma refers to a group of eye conditions that damage the optic nerve, often related to increased pressure within the eye. However, for unclear reasons, different optic nerves have varying susceptibility to damage from a given eye pressure. Glaucoma can lead to visual field loss and blindness in severe cases and when untreated. The main type of glaucoma in Western countries is Primary Open Angle Glaucoma.

Approximately 80 million people live with glaucoma worldwide, including more than three million Americans. The symptoms are usually not noticeable at first, making regular eye exams critical. There is currently no cure for glaucoma, but doctors can effectively use medications and laser and surgical procedures to prevent or slow further damage from occurring.

Why Might Diabetes Increase the Risk of Primary Open Angle Glaucoma?

Multiple studies have found that people with diabetes risk developing glaucoma more than the general population. Adults with diabetes are twice as likely to get glaucoma. The risk increases with the amount of time someone has had diabetes. The link appears to be the strongest for open-angle glaucoma, the most common form. People with diabetes are 48% more likely to develop open-angle glaucoma over 20 years than non-diabetics.

Research has consistently demonstrated a connection between diabetes and various risk factors for glaucoma:

  • Vascular Effects: Diabetes can damage blood vessels throughout the body. In the eye, altered blood flow can impact the nutrition and oxygen supply to the optic nerve, making it more susceptible to damage from high pressure or causing damage by itself.
  • Oxidative Stress: Diabetes and glaucoma have been associated with oxidative stress, which may play a role in the onset and progression of both conditions. Abnormal molecules, called advanced glycation end products, may contribute to oxidative stress in diabetic patients.

What are the Main Known Complications of Diabetes in the Eye?

The most common and well-known eye problems related to diabetes are in the retina.  Over many years, the blood vessels sustain damage, leading to abnormal new blood vessels forming. These abnormal vessels can leak, bleed, or cause scar tissue, leading to retinal detachment or a severe form of secondary glaucoma (neovascular).

Changes in blood sugar can also cause a shift in the focus of the eyes with fluctuating vision.  Chronic diabetes may affect the healing of the cornea and drive the early development of cataracts.

Regular monitoring and controlling blood sugar levels is crucial for diabetic patients, and controlling blood sugar and A1C levels is essential for diabetic patients to lower the risk of blood vessel damage over time.  Maintaining blood sugar levels within the recommended range can mitigate the risk of various complications. A balanced diet, regular physical activity, and medication (when necessary) can effectively manage diabetes.

Does Diabetes Increase the Risk of Primary Open Angle Glaucoma?

Not all studies have shown a positive relationship between diabetes and glaucoma, and it remains a controversial topic.  However, multiple extensive epidemiologic studies have indicated an increased risk of glaucoma in diabetes patients. These studies use large groups of patients to look for connections between different conditions and risk factors.

Meta-analysis combines multiple studies to increase the power and accuracy of answering a specific question.  One meta-analysis indicated an almost one-and-a-half times risk of glaucoma in diabetic subjects.

Risk Factors, Prevention, and Treatment

Understanding the potential connection between these conditions emphasizes the importance of early detection and treatment:

  • Regular Eye Check-ups: Diabetic patients should undergo comprehensive eye exams annually or as recommended by their ophthalmologist.
  • Manage Blood Sugar: Consistent blood sugar management can reduce the risk of complications, including eye conditions.
  • Glaucoma Medications: Several medications can help reduce intraocular pressure for those diagnosed with glaucoma.
  • Glaucoma Laser and Surgery: In advanced cases or when medication isn’t effective, your doctor might recommend surgical interventions like laser trabeculoplasty, micro-invasive glaucoma surgery (MIGS), or more traditional options.

The possible link between diabetes and glaucoma underscores the importance of holistically understanding and managing your health. While having diabetes does elevate the risk for various health risks, early detection, and appropriate treatment can significantly reduce the risk of complications. Maintaining regular check-ups and adhering to prescribed treatments is crucial to safeguard your vision and overall health.

Help Us Provide Hope

With early diagnosis, treatment, and careful monitoring, glaucoma can be successfully treated, preventing it from causing permanent and significant vision impairment.

The diligent work of researchers continues to lead to a better understanding of glaucoma every day. As a result, there’s great hope for new and improved treatments, including superior drug delivery methods, laser treatments, and less invasive surgical techniques. You can help make that happen! Your support can help dedicated researchers continue to discover the causes and cures for glaucoma. In addition, your donations give hope to those living with glaucoma and accelerate our search for a cure.


Article reviewed for medical accuracy by Mark Werner, MD. Posted on November 2, 2023.

Mark Werner, MD

Mark Werner, MD

Dr. Mark Werner is an ophthalmologist and glaucoma specialist caring for patients at Delray Eye Associates in Delray Beach, Florida.