Diabetic Retinopathy

Overview

Diabetic retinopathy is an eye condition that can affect people with diabetes. It occurs when high blood sugar levels damage the small blood vessels in the retina, the light-sensitive layer at the back of the eye. The retina is essential for clear vision, as it sends visual signals to the brain.

In the early stages, diabetic retinopathy may not cause noticeable symptoms. Over time, damaged blood vessels may leak fluid or blood, close off, or cause abnormal new blood vessels to grow. These changes can affect vision and, if not monitored and managed, may lead to serious vision problems.

Regular eye examinations are important for people with diabetes because early detection allows timely care before vision is significantly affected. Good control of diabetes and related health conditions can also help reduce the risk of progression.

Symptoms

Diabetic retinopathy may develop gradually and may not cause symptoms at first. This is why routine eye screening is recommended even when vision seems normal.

Possible symptoms may include:

• Blurred or fluctuating vision
• Difficulty reading or seeing fine details
• Dark spots, strings, or “floaters” in the field of vision
• Reduced night vision
• Colors appearing faded or less clear
• Dark or empty areas in vision
• Sudden vision loss in more advanced cases

Symptoms can occur in one or both eyes. Vision changes in diabetes can also be caused by other eye conditions, so a professional eye examination is needed to understand the cause.

Causes and Risk Factors

The main cause of diabetic retinopathy is long-term damage to retinal blood vessels due to diabetes. High blood sugar can weaken blood vessel walls and affect blood flow in the retina. As the condition progresses, the retina may receive less oxygen, which can trigger the growth of fragile new blood vessels.

Factors that may increase the risk or speed of progression include:

• Having diabetes for a longer period of time
• Poorly controlled blood sugar levels
• High blood pressure
• High cholesterol or other blood fat abnormalities
• Kidney disease related to diabetes
• Pregnancy in a person with diabetes
• Smoking

Both type 1 and type 2 diabetes can lead to diabetic retinopathy. People with diabetes may also develop diabetic macular edema, a related condition in which fluid collects in the central part of the retina called the macula. The macula is responsible for sharp central vision, so swelling in this area can affect reading, driving, and recognizing faces.

Diagnosis

Diabetic retinopathy is diagnosed through a comprehensive eye examination by an ophthalmologist or qualified eye care professional. The examination may include a review of medical history, vision testing, and assessment of the front and back parts of the eye.

Eye drops may be used during the examination to widen the pupils, allowing the doctor to view the retina more clearly. The doctor may look for signs such as leaking blood vessels, retinal swelling, bleeding, abnormal new blood vessels, or scar tissue.

Additional imaging tests may be used when needed. Retinal photography can document changes over time. Optical coherence tomography can show detailed images of the retinal layers and help detect swelling. In some cases, a dye-based imaging test may be used to evaluate blood flow and leakage in the retinal vessels.

The results help determine the stage of diabetic retinopathy and whether treatment or close monitoring is appropriate. Regular follow-up is important because the condition can change over time.

Treatment Options

Treatment depends on the stage of diabetic retinopathy, whether the macula is involved, and the person’s overall health. In early stages, immediate eye treatment may not be necessary, but careful monitoring and good management of diabetes are essential.

General management may include working with healthcare professionals to keep blood sugar, blood pressure, and cholesterol within recommended targets. Lifestyle measures such as healthy eating, regular physical activity, and avoiding smoking may support overall diabetes care. These steps do not replace eye examinations or specialist treatment.

When diabetic retinopathy is more advanced or when macular swelling affects vision, ophthalmic treatments may be recommended. Options may include injections into the eye to reduce abnormal blood vessel activity or swelling, laser treatment to seal leaking vessels or treat areas of poor blood supply, and surgery in selected cases where there is significant bleeding or scar tissue inside the eye.

The aim of treatment is to preserve vision, reduce complications, and slow progression. The most suitable approach varies from person to person and should be discussed with an ophthalmologist after a detailed examination.

When to See a Doctor

People with diabetes should have regular eye examinations as advised by their healthcare team, even if they have no vision symptoms. Screening is important because diabetic retinopathy can be silent in its early stages.

Medical attention should be sought promptly if any of the following occur:

• Sudden blurred vision or vision loss
• A sudden increase in floaters or dark spots
• Flashes of light
• A dark curtain or shadow over part of the vision
• Eye pain or redness with vision changes
• Difficulty performing daily tasks because of vision changes

Pregnant people with diabetes, or those planning pregnancy, should ask their healthcare team about eye monitoring, as pregnancy can affect diabetic eye disease. Early evaluation and regular follow-up can help protect eye health and support timely care.