Keratoconjunctivitis sicca, the clinical term for dry eye disease, is a chronic condition where the eyes do not produce enough tears, or the tears produced are of poor quality. Tears are a complex mix of oil, water, and mucus, and an imbalance in any of these components leads to discomfort and a loss of lubrication on the eye’s surface. A clear and strong link exists between a diagnosis of diabetes and the development of chronic dry eye disease. This association is recognized as a specific complication, often referred to as Diabetic Dry Eye Disease.
Establishing the Link Between Diabetes and Dry Eyes
Diabetes is a leading systemic factor that increases the risk of developing dry eyes, making it a frequent complication for people with the condition. This issue is a manifestation of systemic changes driven by prolonged hyperglycemia, or high blood glucose levels. The risk increases with age and the duration of the diabetes diagnosis, pointing to a progressive impact on the delicate structures of the eye. Studies indicate that prevalence estimates range widely from 15% to over 54%. This high incidence is a direct result of how elevated blood sugar systematically degrades the health of the eye’s surface and tear-producing mechanisms.
The Biological Mechanism Driving Diabetic Dry Eyes
The primary reason diabetes causes dry eyes is through damage to the fine nerves in the front of the eye, a process known as diabetic neuropathy. The corneal nerves serve a sensory function, detecting dryness and triggering the reflex to produce more tears or blink more frequently. When these nerves are damaged by high blood sugar, the eye loses this ability to sense its own dryness, resulting in insufficient tear production and protection.
This neurological damage is compounded by the effect of diabetes on the structure of the tears themselves, leading to tear film instability. Tears are comprised of three layers—a water layer, an oil layer, and a mucus layer—which must remain balanced to prevent rapid evaporation. Chronic hyperglycemia impairs the function of the meibomian glands (oil layer) and also reduces the number of goblet cells (mucus layer). The result is a tear film that is chemically imbalanced and evaporates too quickly from the ocular surface. High glucose levels increase the osmolarity, or saltiness, of the tears, and diabetes promotes chronic inflammation, both of which damage the eye’s surface cells and glands.
Recognizing the Symptoms and Signs
People with diabetic dry eyes often report a persistent, uncomfortable sensation, as though there is sand or grit trapped beneath the eyelid. If these symptoms are frequent or persistent, it suggests the need for a comprehensive eye examination.
Common symptoms include:
- Burning, stinging, or a scratchy feeling in the eyes.
- Noticeable redness of the eyes, indicating irritation and inflammation.
- Sensitivity to light (photophobia).
- Episodes of temporarily blurred vision, especially after prolonged screen use.
- Paradoxical excessive watering, or reflex tearing, as the body attempts to compensate for underlying dryness.
Management and Treatment Strategies for Diabetic Dry Eyes
The most foundational and effective strategy for managing diabetic dry eyes is achieving and maintaining tight control over blood glucose levels. Improving glycemic control can help stabilize corneal nerve function and reduce the chronic inflammatory environment that contributes to the condition. Adequate systemic hydration is also important, as sufficient water intake supports the body’s ability to produce the aqueous component of tears.
For immediate relief and lubrication, preservative-free artificial tears are the first line of over-the-counter treatment. If over-the-counter options are insufficient, an eye care professional may prescribe anti-inflammatory medications, such as cyclosporine or lifitegrast drops. These prescription drops work to suppress the ocular surface inflammation that disrupts normal tear production.
In more persistent cases, small devices called punctal plugs may be inserted into the tear ducts to block drainage and keep tears on the eye’s surface for a longer duration. Specialized treatments, including procedures to help the eyelid oil glands function normally, may also be employed. Regular, comprehensive eye examinations are necessary to monitor the health of the cornea and ocular surface, allowing for early intervention before the condition progresses.