Diabetic Retinopathy and Kidney Disease: Shared Risk Factors
Why Diabetic Retinopathy and Kidney Disease Are Connected
These two complications of diabetes share the same underlying cause: damage to tiny blood vessels throughout the body. Because they develop through the same process, it is very common for people to be affected by both at the same time.
The retina at the back of the eye and the filtering units of the kidneys, called glomeruli, both depend on networks of extremely small capillaries to function properly. When blood sugar stays elevated over many years, these capillaries become weakened and leaky. The same process of blood vessel damage unfolds in both organs simultaneously, which is why problems in the eyes and kidneys so often appear together in people with diabetes.
This shared vulnerability also explains why your eye specialist may ask about your kidney function and why your kidney doctor may ask about your most recent eye exam. The health of the blood vessels in one organ can serve as a signal for what is happening in the other.
Poorly controlled blood sugar is the primary driver of damage to small blood vessels throughout the body. High blood pressure places additional stress on already weakened capillaries in both the retina and the kidneys. Abnormal cholesterol and triglyceride levels contribute to inflammation and hardening of blood vessel walls, and the longer a person has had diabetes, the greater the cumulative exposure to these damaging forces.
Smoking accelerates blood vessel damage and increases the risk of progression for both conditions. Genetic factors also play a role, as some people appear more susceptible to this type of small vessel damage than others, even when their blood sugar control is similar. Recognizing these shared risk factors matters because controlling them can slow the progression of both conditions at the same time.
People with significant diabetic retinopathy are more likely to also have some degree of kidney impairment, and people with established diabetic kidney disease are more likely to have retinopathy than those with normal kidney function. This overlap is not coincidental. It reflects the same systemic disease process affecting both organs.
In clinical practice, the presence of diabetic retinopathy can serve as a supporting clue when evaluating kidney disease. If a person with diabetes has protein in their urine, which is a sign of kidney damage, and also has diabetic retinopathy, it increases the likelihood that the kidney disease is directly caused by diabetes rather than by another unrelated condition.
How Blood Sugar, Blood Pressure, and Cholesterol Affect Both Organs
The three major drivers of diabetic complications are elevated blood sugar, high blood pressure, and abnormal cholesterol. Each one causes harm to the delicate capillaries in both the retina and the kidneys, and managing all three is essential for protecting both organs.
When blood sugar remains high over time, excess glucose attaches to proteins in blood vessel walls through a process called glycation. This creates harmful compounds that stiffen vessel walls, trigger inflammation, and impair the normal function of the endothelium, which is the thin inner lining of blood vessels. In the retina, this leads to microaneurysms (tiny balloon-like bulges in vessel walls), bleeding, and eventually the growth of abnormal new blood vessels. In the kidneys, it damages the delicate filtering membrane of the glomeruli, allowing protein to leak into the urine.
Improving blood sugar control has been shown to reduce the risk of both conditions progressing to more advanced stages. Hemoglobin A1c, often called HbA1c, is a blood test that reflects average blood sugar levels over the past two to three months and is one of the most important numbers to monitor. Your primary care provider and diabetes care team can help you set an HbA1c target and build a plan using diet, exercise, and medication to reach it.
High blood pressure, or hypertension, acts as an accelerator for the damage caused by elevated blood sugar. When blood pressure is high, the force of blood pushing through tiny capillaries increases, which can cause already weakened vessels to leak, rupture, or scar. In the retina, this additional pressure worsens the bleeding and fluid leakage that characterize diabetic retinopathy. In the kidneys, it damages the glomerular capillaries and speeds up the loss of filtering capacity over time.
Controlling blood pressure is one of the most impactful steps you can take to protect both organs. A class of blood pressure medications that targets the renin-angiotensin system has been shown to provide extra protection for the kidneys in people with diabetes. Your provider may prescribe these medications even if your blood pressure is only mildly elevated, because the protective benefits extend beyond blood pressure reduction alone.
Abnormal levels of cholesterol and triglycerides, a condition called dyslipidemia, contribute to blood vessel damage throughout the body. Elevated LDL (low-density lipoprotein) cholesterol promotes the buildup of fatty deposits in blood vessel walls, while high triglyceride levels increase inflammation. In the retina, dyslipidemia has been linked to the formation of hard exudates (yellowish deposits of leaked fat and protein) and may contribute to macular edema, which is swelling at the center of the retina. In the kidneys, lipid abnormalities accelerate scarring of the glomeruli and contribute to the progressive loss of kidney function.
Chronic low-grade inflammation is another shared pathway that weakens capillaries in both organs. Managing cholesterol and triglycerides through diet, exercise, and medication when needed can reduce this inflammatory burden and offer protection to both the retina and the kidneys simultaneously.
What Retinopathy May Reveal About Your Kidney Health
Because a dilated eye exam allows your eye specialist to directly observe the blood vessels in your retina, what we see there can provide important clues about what may be happening elsewhere in your body, including your kidneys.
The retina is the only place in the body where blood vessels can be viewed directly without surgery. Changes seen in the retinal vessels, such as narrowing, leakage, or the growth of abnormal new vessels, reflect broader vascular damage that may be affecting the kidneys, heart, and brain at the same time. Diabetic retinopathy is sometimes detected before kidney disease becomes apparent on standard blood and urine tests, which means an eye exam finding can prompt earlier kidney evaluation.
When your eye specialist finds signs of retinopathy, sharing that information with your primary care provider can lead to closer monitoring of your kidney function, potentially catching kidney problems at an earlier and more treatable stage.
There is a general correlation between the severity of diabetic retinopathy and the likelihood of significant kidney involvement. People with no retinopathy or only mild changes tend to have better kidney function than those with moderate or severe retinopathy. Patients with proliferative diabetic retinopathy, the most advanced stage where abnormal new blood vessels grow on the retina, are more likely to have significant protein in their urine and reduced kidney filtering capacity.
However, this correlation is not absolute. Some people develop severe retinopathy with relatively well-preserved kidney function, and others develop significant kidney disease with only mild retinal changes. Individual variation in genetics and blood vessel anatomy means the two organs do not always progress in tandem, so your doctors will monitor each organ independently rather than relying on one to predict the other.
If you have been diagnosed with diabetic retinopathy, it is a good idea to confirm that your kidney function is being monitored regularly. Standard kidney screening for people with diabetes includes a blood test to measure your estimated glomerular filtration rate (eGFR), which assesses how well your kidneys filter waste, and a urine test to check for albumin, a protein that leaks into the urine when the kidney filters are damaged. These tests are simple and recommended at least once a year for most people with diabetes.
If your eye specialist tells you that your retinopathy has progressed, let your primary care provider know so they can evaluate whether your kidney monitoring schedule should be adjusted. Early detection of kidney disease opens the door to treatments that can slow progression and help delay or prevent the need for dialysis.
Coordinating Care Between Your Eye and Kidney Specialists
Managing both diabetic retinopathy and diabetic kidney disease works best when your healthcare providers share information and align their recommendations. A team-based approach reduces the risk of conflicting advice and ensures that the overall plan is optimized for your health.
Your eye specialist focuses on monitoring and treating the retina, your nephrologist (kidney specialist) focuses on preserving kidney function, and your primary care provider and endocrinologist manage the underlying diabetes, blood pressure, and cholesterol that drive both conditions. When these providers communicate with each other, important details are less likely to be overlooked.
For example, certain medications used to protect the kidneys may also benefit the retina, while some treatments for advanced retinopathy should be discussed with your kidney specialist if you have severe kidney impairment. Sharing your test results, treatment plans, and medication lists with all of your providers helps everyone on your care team make the most informed decisions.
People with diabetes who require dialysis, a treatment that filters the blood when the kidneys can no longer do so adequately, tend to have a higher prevalence of diabetic retinopathy. The fluid shifts and blood pressure changes that occur during dialysis sessions can temporarily affect vision and may place additional stress on the retinal blood vessels. Maintaining consistent blood pressure management during and between dialysis sessions is important for protecting the retina.
After a successful kidney transplant, improvements in blood sugar control and blood pressure may have positive effects on the retina over time. However, the immunosuppressive medications required after a transplant can affect blood sugar and blood pressure, so close monitoring by your entire healthcare team remains essential. Regular retinal exams should continue after a kidney transplant to track any changes and adjust treatment as needed.
Several treatments and lifestyle strategies help both the retina and the kidneys at the same time. Tight blood sugar control, blood pressure management, and cholesterol treatment with statins all reduce damage to small blood vessels in both organs. Newer classes of diabetes medications, including SGLT2 inhibitors and GLP-1 receptor agonists, have demonstrated protective effects on the kidneys and cardiovascular system, and ongoing research is exploring whether they may also benefit the retina.
Ask your diabetes care team whether any of these newer medications might be appropriate for you based on your individual health profile. The goal is to address the root causes of vascular damage in a way that protects every organ that depends on healthy small blood vessels.
Protecting Your Eyes and Kidneys for the Long Term
The daily choices you make, combined with consistent medical monitoring, are the most powerful tools you have for preserving both your vision and your kidney function over time.
A balanced diet that is lower in sodium, refined sugars, and unhealthy fats helps manage blood sugar, blood pressure, and cholesterol. Regular physical activity improves insulin sensitivity, lowers blood pressure, and supports overall cardiovascular health. Avoiding tobacco eliminates a major source of blood vessel damage and inflammation that accelerates both retinopathy and kidney disease.
Staying hydrated, managing stress, and getting enough sleep also contribute to better vascular health overall. No single lifestyle change prevents the progression of diabetic complications on its own, but the combined effect of multiple healthy habits creates a strong foundation that supports every organ that depends on small blood vessels.
Both diabetic retinopathy and kidney disease can progress without noticeable symptoms in the early stages, which makes regular screening essential. A dilated eye exam at least once a year allows your eye specialist to detect retinal changes before they affect your vision. Annual blood and urine tests for kidney function allow your primary care provider to catch signs of kidney damage early, when treatment options are most effective.
Keeping all of your screening appointments, even when you feel well, is one of the most important things you can do. By the time symptoms such as blurry vision or leg swelling appear, the underlying damage may already be advanced. Regular monitoring keeps problems manageable while they are still in an early stage.
Staying actively involved in your healthcare makes a meaningful difference when managing conditions that affect multiple organs. Keep track of your HbA1c, blood pressure readings, cholesterol levels, eGFR, and urine albumin results so you can see trends over time. Ask your providers to explain any changes in your numbers and what they mean for your treatment plan, and bring a list of questions to each appointment.
The connection between your eyes and kidneys is a reminder that diabetes is a whole-body disease. Every step you take to manage your blood sugar, blood pressure, and cholesterol protects not just one organ, but many, including your retina, your kidneys, your heart, and your overall quality of life for years to come.
Frequently Asked Questions
Here are answers to questions we often hear from patients managing both diabetic eye disease and kidney health concerns.
Not necessarily, but retinopathy is a meaningful signal that closer kidney monitoring is warranted. Because the same vascular damage process drives both conditions, your risk of kidney involvement is higher than someone with no retinopathy. Ask your primary care provider to check your eGFR and urine albumin if you have not had these tests recently. Catching kidney changes early, before any symptoms appear, gives you the best chance of slowing or preventing further damage.
More advanced retinopathy is generally associated with a greater likelihood of kidney involvement, but the relationship is not precise enough to rely on for diagnosis. Some people have severe retinopathy with relatively well-preserved kidney function, and others have significant kidney disease with only mild retinal changes. Your eye findings can guide your providers to look more closely, but kidney function must be assessed directly through blood and urine testing rather than inferred from eye exam results alone.
Yes, and you can help make that happen by sharing test results and treatment updates with each provider at your appointments. Bringing a current medication list and copies of recent lab work helps every member of your care team make well-informed decisions. If you notice that your providers seem unaware of each other's findings or recommendations, it is entirely appropriate to ask them to communicate directly. Coordinated care reduces the risk of gaps or conflicts in your treatment plan.
Dialysis does not directly treat or worsen retinopathy, but the fluid and blood pressure changes that occur during dialysis sessions can temporarily affect vision and place added stress on retinal blood vessels. Consistent blood pressure management during and between sessions helps minimize this risk. If you are on dialysis, regular dilated eye exams remain important so your eye specialist can monitor for any changes and intervene early if needed.
SGLT2 inhibitors and GLP-1 receptor agonists, two newer classes of diabetes medications, have demonstrated meaningful protective effects on the kidneys and cardiovascular system. Research into whether these medications also benefit the retina is ongoing, and early findings are encouraging. Whether these treatments are right for you depends on your overall health, other medications you take, and your diabetes care team's assessment of your individual situation. This is a good topic to raise at your next diabetes management appointment.
Most people with diabetes are recommended to have a dilated eye exam at least once a year and annual kidney screening with eGFR and urine albumin testing. If either condition is already present or progressing, your doctors may recommend more frequent monitoring. The key decision-maker is your care team, who will base the schedule on the current stage of each condition and how well your blood sugar, blood pressure, and cholesterol are controlled. Do not wait for symptoms to prompt a visit, as both conditions often progress silently until significant damage has occurred.
Schedule Your Diabetic Eye Exam at Rhode Island Eye Institute
At Rhode Island Eye Institute, our team of specialists has extensive experience caring for patients with diabetic retinopathy and related complications. We work closely with your broader care team to ensure your retinal health is monitored thoroughly and that any changes are addressed promptly. If you have diabetes and are overdue for a dilated eye exam, or if you have recently been told you have retinopathy and want a specialist evaluation, we encourage you to reach out and schedule an appointment at one of our convenient locations.