Diabetic Retinopathy- Causes, Symptoms, Treatment, and Prevention Guide

What Is Diabetic Retinopathy?

Diabetic retinopathy usually affects the eyes, damaging the blood vessels in the retina. The two stages of diabetic retinopathy are proliferative diabetic retinopathy, which occurs when new blood vessels grow, and neovascular diabetic retinopathy, which is a later stage of the condition. These new blood vessels leak into the gel-like substance present in the eye, known as vitreous. The bleeding blocks the vision. The second stage is non-proliferative diabetes-related retinopathy, which occurs in the early stage and affects diabetic people. The blood vessels leak into the retina. This manifests with either bleeding, fluid, or lipid. It can lead to poor blood flow.

Who Is at Risk of Developing Diabetic Retinopathy?

Anyone with diabetes or the underlying conditions can develop diabetic retinopathy:

• Individuals with type 1 diabetes.

• Individuals with type 2 diabetes.

• Gestational diabetes (raised levels of blood glucose during pregnancy).

• Increased blood pressure.

• Uncontrolled blood sugar.

• Hyperlipidemia (a condition characterized by high levels of fat in the body).

What Are the Risk Factors For Diabetic Retinopathy?

Diabetic retinopathy can develop due to several risk factors. These are divided into modifiable (things you can control) and non-modifiable (things you cannot change).

Modifiable risk factors are :

• High blood sugar (hyperglycemia): This is the main cause of eye damage in diabetes. Maintaining blood sugar control (HbA1c below 7%) reduces the risk.

• High blood pressure (hypertension): Controlling blood pressure in diabetes (type 2) can lower the risk of eye problems by 37%.

• High cholesterol (dyslipidemia): Poor cholesterol levels can harm the blood vessels in the eyes. Some medications for cholesterol may also affect insulin levels.

• Obesity: Being overweight, especially in type 1 diabetes, increases the risk of diabetic retinopathy.

Non-modifiable risk factors:

• Puberty: Hormonal changes after puberty make eye problems more likely.

• Pregnancy: Women with diabetes may see faster worsening of retinopathy during pregnancy and need regular eye checkups.

How Does Diabetic Retinopathy Develop?

The following are the two stages:

• Non-proliferative diabetic retinopathy (NPDR) is the early stage of the condition, characterized by blood vessel leakage into the retina. Its manifestation can be seen in the form of hemorrhage, fluid, or lipid. Over time, these blood vessels can close, leading to poor blood flow (ischemia).

• In proliferative diabetes-related retinopathy (PDR), as the disease progresses, abnormal blood vessels can develop to compensate for poor blood flow. This process is called neovascularization. Since the newly formed blood vessels are fragile, they can leak blood into the vitreous (the gel-like substance of the eye), which can accumulate. These new blood vessels can result in the formation of scar tissue, which can lead to a detached retina. This is a serious condition that can affect both central and peripheral (side) vision.

What Are the Symptoms of Diabetic Retinopathy?

The symptoms are as follows:

• Blurred vision - This can occur due to various vascular retinal changes caused by diabetes.

• A sudden severe blackout lasting minutes to seconds can be due to vitreous hemorrhage.

• A distorted image can be due to diabetic macular edema (leakage of blood vessels into the part of the retina called the macula). It can also be due to secondary retinal vein occlusions.

• A retinal detachment can occur in advanced proliferative diabetic retinopathy.

• Developing new color blindness or the appearance of faded colors.

• Poor vision at night (night blindness).

• Streaks or small dark spots (eye floaters) in the vision.

• Difficulty in reading or seeing distant objects.

• A sudden or complete loss of vision.

• An empty or dark spot in the center of vision.

• Other vision-threatening problems are ischemic optic neuropathy and severe dry eyes.

How Is Diabetic Retinopathy Diagnosed?

A dilated eye examination is done by an ophthalmologist (eye doctor) using eye drops. These drops widen the pupils, allowing the physician a clear view of the inside of the eye. The physician will examine the patient for signs of swelling, abnormal blood vessels, scarring, and optic nerve damage.

Other diagnostic tests include:

• In fluorescein angiography tests, a dye is injected into the arm, allowing the physician to visualize how blood flows into the eye. When the pupils are dilated, pictures of the dye that circulates inside the eye are taken to identify which vessels are leaking, blocked, or broken.

• Optical coherence tomography (OCT) uses light waves to capture images of the retina. The thickness of the retina can be estimated using these images. This test enables the doctors to determine the level of fluid that has accumulated in the retina.

• The visual acuity test is done to determine how clearly a person can see things.

• Intraocular pressure is checked to rule out glaucoma.

• The function of the eye muscles is checked to see how well one can move their eye.

• Examination of peripheral or side vision.

• The pupils' response to light is checked.

How Is Diabetic Retinopathy Treated?

Diabetic retinopathy is treated with medications and surgery, depending on how advanced it is.

1. Medications:

• Control blood sugar: The primary step is to keep diabetes under control with pills or insulin.

• Eye injections (Anti-VEGF): Medicines like Aflibercept, Bevacizumab, or Ranibizumab are injected into the eye. They prevent the growth of harmful blood vessels, reduce swelling, and can improve vision. The eye is numbed first. Injections may start monthly and then be reduced gradually.

• Eye drops for glaucoma: In cases where new blood vessels increase eye pressure (neovascular glaucoma), medications such as Timolol or Brimonidine can help lower the pressure. However, these drops usually give only temporary relief.

2. Surgery:

• Vitrectomy: This is an eye surgery that removes some or all of the fluid from the eye. For excessive damage, surgeons excise the blood and any scar tissue to stop further damage and protect vision.

• Laser treatment: Laser surgery seals leaking blood vessels and slows the growth of abnormal vessels. This helps protect vision, especially in advanced stages.

Even with treatment, vision may not fully recover, so controlling blood sugar levels and regular eye check-ups are crucial to prevent serious problems.

When Should You See an Ophthalmologist?

People with diabetes should see an eye doctor. Signs that need prompt consultation include:

• Sudden blurring or worsening of vision.

• Seeing multiple floating spots or “floaters” in the eye.

• A shadow or curtain-like effect blocks a part of the vision.

• Eye pain along with blurred or foggy vision.

Early consultation can help prevent serious complications and protect your eyesight.

Can Diabetic Retinopathy Be Prevented?

Diabetic retinopathy can be prevented in the following ways:

• Maintaining the blood sugar level under control.

• Refraining from smoking.

• Exercising regularly.

• Undertaking eye examinations annually.

• Maintaining normal blood pressure.

• Taking the medications appropriately as prescribed by the physician.

Conclusion:

Diabetic retinopathy is a preventable and treatable disease, provided patients have good compliance with follow-ups and present early during the disease progression. Proper treatment with control of sugars in the diet can mitigate vision loss and support a healthy eye and good vision.

Key Takeaway From iCliniq:

• Diabetic retinopathy is a complication of diabetes. An increased blood sugar level damages the retina's blood vessels, the light-sensitive tissue present at the back of the eyes.

• Initially, it may be asymptomatic, but with time, it could lead to blindness.

If you have diabetic retinopathy or you know someone suffering from it, consult an iCliniq ophthalmologist to get your eye treated by the best team of doctors.