Diabetic eye disease encompasses a group of vision-threatening conditions that affect individuals living with diabetes. These conditions include diabetic retinopathy, diabetic macular edema (DME), cataracts, and glaucoma. If left unmanaged, diabetes-related damage to the eyes can lead to significant vision impairment and even blindness. However, proactive management of diabetes and regular eye examinations are crucial steps in preventing the onset or progression of diabetic eye disease, safeguarding your vision.
Effective diabetes management is paramount in maintaining eye health. This involves diligently controlling blood glucose levels, blood pressure, and cholesterol – often referred to as the diabetes ABCs. For individuals who smoke, seeking support to quit is another vital step. Furthermore, a comprehensive, dilated eye exam conducted annually is indispensable for early detection and intervention.
Alt text: Ophthalmologist performing a dilated eye exam on a male patient to diagnose diabetic eye disease.
Even if your vision seems unaffected, a thorough, dilated eye exam remains the most reliable method for detecting early signs of diabetic eye disease. Often, the initial stages of diabetic eye disease and associated vision loss are asymptomatic. A dilated eye exam enables your eye doctor to identify and address potential issues promptly, often before substantial vision loss occurs. Early diagnosis is key to effective management and preserving sight.
How Diabetes Impacts Your Eyes
Diabetes exerts its effects on the eyes primarily through elevated blood glucose levels, also known as blood sugar.
In the short term, high blood glucose is unlikely to cause permanent vision loss. However, temporary blurry vision is a common experience for individuals adjusting their diabetes management plan or medications. Elevated glucose levels can disrupt fluid balance and induce swelling in the eye tissues responsible for focusing, leading to transient blurred vision. This type of visual disturbance is temporary and typically resolves as blood glucose levels stabilize within a normal range.
However, sustained high blood glucose levels over time can inflict damage on the delicate blood vessels located at the back of the eyes. This damage can commence even during prediabetes, a state characterized by blood glucose levels higher than normal but not yet meeting the diagnostic criteria for diabetes. The compromised blood vessels may become leaky, causing swelling, and trigger the growth of new, fragile blood vessels. These newly formed vessels are prone to bleeding into the vitreous humor (the gel-like substance filling the eye), leading to scarring, or causing a dangerous elevation of pressure within the eye.
The majority of severe diabetic eye diseases originate from these blood vessel complications. The four major eye conditions that pose a threat to vision in individuals with diabetes are:
Diabetic Retinopathy
The retina, the light-sensitive lining at the back of each eye, plays a crucial role in vision. It converts light into electrical signals that are transmitted to the brain, enabling sight. Diabetic retinopathy arises when damaged blood vessels impair the retina’s function.
Early-stage diabetic retinopathy, known as nonproliferative diabetic retinopathy (NPDR), is characterized by weakened blood vessels that may bulge (microaneurysms) or leak blood and fluid into the retina.
As the disease progresses, it can advance to proliferative diabetic retinopathy (PDR). In PDR, some blood vessels in the retina become blocked, prompting the growth of new, abnormal blood vessels on the retinal surface. These fragile new vessels are prone to bleeding and can lead to severe vision loss.
Alt text: Normal vision illustration depicting two boys playing with rubber balls, used to compare with vision affected by diabetic retinopathy.
Alt text: Simulated vision of diabetic retinopathy showing dark spots obstructing the view of two boys playing, highlighting the impact on sight.
Diabetic Macular Edema
The macula, the central part of the retina, is essential for sharp, detailed vision required for activities like reading, driving, and facial recognition. Diabetic macular edema (DME) is characterized by swelling in the macula due to fluid leakage from damaged blood vessels. Over time, DME can destroy the macula’s delicate structure, leading to significant vision loss or blindness. Macular edema commonly develops in individuals already exhibiting signs of diabetic retinopathy.
Glaucoma
Glaucoma represents a group of eye diseases that damage the optic nerve, the crucial nerve bundle connecting the eye to the brain. Diabetes significantly elevates the risk of developing glaucoma, doubling the likelihood compared to individuals without diabetes. Untreated glaucoma can lead to progressive vision loss and blindness.
Symptoms of glaucoma vary depending on the specific type. Primary open-angle glaucoma, the most common form, often progresses gradually with minimal noticeable symptoms in the early stages. Angle-closure glaucoma, a less common but more acute form, can present with sudden eye pain, blurred vision, and halos around lights.
Alt text: Illustration of vision with glaucoma, showing peripheral vision loss with shadows encroaching from the sides, affecting the view of two boys.
Cataracts
Cataracts are characterized by the clouding of the eye’s natural lens, which is normally clear and responsible for focusing light onto the retina for sharp vision. While cataracts are a common age-related condition, individuals with diabetes are more prone to developing them and at an earlier age. Researchers believe that elevated glucose levels contribute to the buildup of deposits within the lens, leading to cloudiness.
Alt text: Vision simulation of cataracts causing blurry and faded vision of two boys playing, demonstrating the visual impairment.
Prevalence of Diabetic Eye Disease
Diabetic Retinopathy Statistics
Approximately one in three individuals with diabetes over the age of 40 already exhibit some signs of diabetic retinopathy. It stands as the leading cause of vision loss among people with diabetes. However, early diagnosis and timely treatment of diabetic retinopathy can drastically reduce the risk of blindness by as much as 95 percent. Regular eye care is therefore crucial in maintaining vision health for individuals with diabetes.
Glaucoma and Cataract Prevalence
Individuals with diabetes face approximately twice the risk of developing glaucoma and cataracts compared to those without diabetes. This elevated risk underscores the importance of proactive eye care and regular screenings for people with diabetes to facilitate early detection and management of these conditions.
Risk Factors for Diabetic Eye Disease
Anyone with diabetes is susceptible to developing diabetic eye disease. However, certain factors elevate the risk:
- Poorly managed high blood glucose: Inadequate control of blood sugar levels significantly increases the risk.
- Uncontrolled high blood pressure: Hypertension further exacerbates the risk.
Elevated blood cholesterol and smoking are also recognized as contributing risk factors for diabetic eye disease.
Certain ethnic and demographic groups are disproportionately affected. African Americans, American Indians and Alaska Natives, Hispanics/Latinos, Pacific Islanders, and older adults face a greater risk of vision loss or blindness from diabetes.
Pregnancy in women with diabetes can also pose a heightened risk. If a woman has pre-existing diabetic retinopathy, it can worsen during pregnancy due to hormonal and metabolic changes. Therefore, pregnant women with diabetes require close monitoring and regular eye exams throughout their pregnancy to detect and manage any developing eye problems promptly.
Gestational diabetes, diabetes that develops during pregnancy and typically resolves after childbirth, does not usually cause diabetic eye disease. The reasons for this difference are not fully understood.
The duration of diabetes is also a significant risk factor. The longer an individual has diabetes, the higher their likelihood of developing diabetic eye disease.
Symptoms of Diabetic Eye Disease
In the early stages, diabetic eye disease often presents without noticeable symptoms. Damage can be developing within the eyes without any pain or changes in vision, particularly in diabetic retinopathy.
When symptoms do manifest, they may include:
- Blurred or wavy vision
- Fluctuating vision, varying from day to day
- Dark spots or areas of vision loss
- Impaired color vision
- Spots or dark strings floating in vision (floaters)
- Flashes of light
If you experience any of these symptoms, it is essential to consult with your eye doctor promptly for a comprehensive evaluation.
When to Seek Immediate Medical Attention
Seek immediate medical attention from an eye doctor if you experience sudden vision changes, such as:
- Sudden flashes of light
- A significant increase in floaters
- A sensation of a curtain obstructing your vision
These symptoms may indicate a detached retina, a serious medical emergency requiring immediate treatment to prevent permanent vision loss.
Diabetic Eye Disease Diagnosis
A comprehensive, dilated eye exam is the cornerstone of Diabetic Eye Disease Diagnosis. During this examination, your eye doctor will administer eye drops to dilate your pupils, widening them to allow for a more extensive view of the retina and optic nerve. This dilation enables the doctor to use specialized magnifying lenses to thoroughly examine the back of each eye. It’s important to note that vision will be blurred for a few hours following a dilated exam due to the effect of the eye drops.
In addition to the dilated eye exam, the diagnostic process may include:
- Visual acuity test: To assess the sharpness of your vision at different distances.
- Tonometry: To measure the pressure inside your eyes, helping to detect glaucoma.
Depending on your individual health history and the findings of the initial examination, your doctor may recommend further diagnostic tests, such as:
- Optical coherence tomography (OCT): An imaging technique that provides detailed cross-sectional images of the retina to detect macular edema and other retinal abnormalities.
- Fluorescein angiography: A procedure involving injecting a dye into the bloodstream to visualize blood flow in the retina and identify leaky blood vessels.
Most individuals with diabetes should undergo a comprehensive eye exam, including dilation, at least once a year. Your eye care team may recommend a more frequent examination schedule based on the type of diabetes you have, the duration of your diabetes, and the presence of any existing eye conditions.
Treatment Options for Diabetic Eye Disease
Treatment strategies for diabetic eye disease often involve a combination of managing diabetes itself and addressing the specific eye conditions. This includes meticulous management of the diabetes ABCs – A1c (blood glucose control), blood pressure, and cholesterol – as well as smoking cessation for smokers. Your healthcare team will provide personalized guidance on achieving these management goals.
Alt text: Woman checking her blood glucose level with a meter, emphasizing the importance of blood glucose management in diabetic eye disease prevention.
For advanced diabetic eye problems, treatment modalities may include medication, laser therapy, surgery, or a combination thereof.
Medication
Anti-VEGF (vascular endothelial growth factor) medications, such as aflibercept, bevacizumab, and ranibizumab, are frequently used to treat diabetic eye diseases, particularly DME and proliferative diabetic retinopathy. These medications work by blocking VEGF, a protein that stimulates the growth of abnormal blood vessels in the eye and contributes to fluid leakage.
Anti-VEGF medications are administered via injection directly into the eye during office visits. Typically, a series of injections are given over the first few months, followed by less frequent maintenance treatments. Local anesthetic is used to numb the eye, minimizing discomfort during the injections.
Anti-VEGF therapy can effectively halt further vision loss and, in some cases, improve vision.
Laser Treatment
Laser photocoagulation employs a focused beam of light to create tiny burns within the eye. This technique is used to treat leaky blood vessels and macular edema. Laser treatment is usually performed in multiple office visits, with local anesthesia to numb the eye.
Laser therapy can effectively prevent the progression of diabetic eye disease, which is crucial for preventing vision loss and blindness. However, laser treatment is less likely to restore vision that has already been lost compared to anti-VEGF medications.
Two main types of laser treatment are used:
- Focal/grid laser treatment: Targets a small area of the retina to treat diabetic macular edema.
- Scatter laser treatment (panretinal photocoagulation – PRP): Treats a wider area of the retina and is used for proliferative diabetic retinopathy to reduce the growth of abnormal blood vessels.
Vitrectomy
Vitrectomy is a surgical procedure to remove the vitreous gel, the clear gel that fills the center of the eye. It is indicated for severe bleeding in the vitreous humor or scar tissue formation caused by proliferative diabetic retinopathy. Scar tissue can pull on the retina, potentially leading to retinal detachment, a sight-threatening condition.
During vitrectomy, a clear saline solution is gently infused into the eye to maintain eye pressure and replace the removed vitreous gel. Vitrectomy is performed in a surgery center or hospital under anesthesia.
Cataract Surgery
Cataract surgery involves removing the clouded lens (cataract) and replacing it with an artificial lens. This procedure is typically performed in a surgery center or hospital. Cataract surgery generally leads to improved vision. After the eye heals, a new glasses prescription may be needed. The extent of vision improvement after cataract surgery may also depend on the presence and treatment of any underlying diabetic retinopathy or macular edema.
Protecting Your Eyes from Diabetic Eye Disease
To prevent diabetic eye disease or slow its progression, prioritize managing your diabetes ABCs: A1c, blood pressure, and cholesterol. If you smoke, quitting smoking is crucial.
Regular dilated eye exams, at least annually or more frequently as recommended by your eye care professional, are essential for early detection and intervention. These proactive measures are powerful tools in safeguarding your eye health and preventing blindness.
Early and consistent management of diabetes and related health conditions yields the greatest benefits. Even if you have faced challenges in managing your health in the past, taking steps to improve your health now can protect your vision in the future. It is never too late to start prioritizing your eye health.
Managing Vision Loss from Diabetes
If you have already experienced vision loss due to diabetes, consult your eye care professional about low vision rehabilitation services. Low vision specialists can provide guidance and resources to help you manage vision loss that cannot be corrected with glasses, contact lenses, medication, or surgery. Assistive devices and specialized training can help you maximize your remaining vision, enabling you to maintain an active lifestyle, pursue hobbies, connect with loved ones, and live independently.
References
Last Reviewed May 2017
This content is provided as a service of the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), part of the National Institutes of Health. NIDDK translates and disseminates research findings to increase knowledge and understanding about health and disease among patients, health professionals, and the public. Content produced by NIDDK is carefully reviewed by NIDDK scientists and other experts.
The NIDDK would like to thank: Neil M. Bressler, MD, The Wilmer Eye Institute, Johns Hopkins University School of Medicine; Emily Chew, MD, National Eye Institute (NEI)
