Prediabetes, with elevated blood sugar not yet diagnostic of type 2 diabetes, can affect various body systems, including the eyes. Even at this stage, high blood sugar can initiate changes leading to vision problems. Early intervention can prevent or delay serious eye complications.
Understanding Prediabetes
Prediabetes signals that the body is struggling to manage blood glucose effectively. A diagnosis is typically made when fasting blood glucose levels are between 100 and 125 milligrams per deciliter (mg/dL), or an A1C test shows a range of 5.7% to 6.4%. The A1C test provides an average of blood sugar levels over the past two to three months. This condition affects a significant portion of the population; in 2021, an estimated 97.6 million U.S. adults (about 38%) had prediabetes.
Despite its widespread prevalence, more than 80% of individuals with prediabetes are unaware they have it. Risk factors include being overweight, physical inactivity, unhealthy eating habits, age (especially over 45), and a family history of type 2 diabetes. Prediabetes warns of a higher risk of progressing to type 2 diabetes and other health complications if not addressed.
How Prediabetes Affects Eye Health
Elevated blood sugar, even below diabetes thresholds, can damage delicate eye structures. The retina, the light-sensitive tissue at the back of the eye, contains tiny blood vessels. Consistently high or fluctuating blood sugar can weaken these capillaries, causing them to swell, leak, or even become completely blocked. This is microvascular damage.
Fluid accumulation from leaky vessels causes swelling, while blocked vessels deprive the retina of nutrients and oxygen. The body may compensate by growing new, fragile blood vessels on the retinal surface. These new vessels are prone to bleeding, which can further obscure vision. Prolonged high blood sugar can also damage eye nerves.
Specific Vision Problems Linked to Prediabetes
Prediabetes can contribute to several eye conditions, often associated with full-blown diabetes. Blurry vision is a common early symptom, often temporary, resulting from fluid shifts in the eye’s lens due to fluctuating blood sugar levels. When blood sugar stabilizes, vision typically returns to normal. However, persistent high blood sugar can cause more lasting changes.
Diabetic retinopathy, a serious condition damaging retinal blood vessels, can begin during prediabetes. Damage manifests as weakening, bulging (microaneurysms), or leaking of tiny retinal capillaries. Research indicates that nearly 8% of individuals can develop mild diabetic retinopathy while still in the prediabetic stage. If left unmanaged, this condition can progress, leading to scar tissue formation and potential vision loss.
Cataracts, a clouding of the eye’s natural lens, are also influenced by prediabetes. Prediabetes can lead to cataracts developing more frequently and at an earlier age. High blood sugar alters lens proteins, causing clouding and impairing vision. The increased glucose can lead to the accumulation of sorbitol within lens cells, which contributes to this clouding.
Glaucoma, which damages the optic nerve and can lead to permanent vision loss, also links to elevated blood sugar. High blood glucose levels increase glaucoma risk, with some studies suggesting a doubled risk for those with diabetes. This increased risk can be due to abnormal blood vessel growth blocking fluid drainage, increasing eye pressure.
Protecting Your Vision with Prediabetes
Proactive steps are important to mitigate vision problems for individuals with prediabetes. Maintaining healthy blood sugar is a primary focus, achieved through consistent dietary changes. Eating a balanced diet rich in fruits, vegetables, and whole grains, while reducing processed foods and sugary beverages, helps stabilize glucose levels.
Regular physical activity helps manage blood sugar and improve insulin sensitivity. Aiming for at least 150 minutes of moderate-intensity exercise per week, such as brisk walking, can be beneficial. Achieving and maintaining a healthy weight significantly reduces the risk of prediabetes progressing to type 2 diabetes and helps protect eye health. Losing even a small percentage of body weight can make a difference.
Quitting smoking is important, as it increases insulin resistance and blood vessel damage risk throughout the body, including the eyes. Beyond lifestyle, regular eye exams are important for early detection. An annual comprehensive dilated eye exam allows professionals to identify issues like early diabetic retinopathy before significant vision loss. Working closely with healthcare providers to monitor blood sugar and overall health is essential for preserving vision.