Diabetic Retinopathy: Symptoms, Causes & Treatment

Diabetic retinopathy is a serious complication of diabetes affecting the small blood vessels in the retina—the light-sensitive tissue at the back of the eye responsible for vision. Prolonged high blood sugar damages these vessels gradually, potentially causing vision loss or blindness if not detected and treated early.

The disease has two main types: nonproliferative (mild), where weakened vessels leak fluid and blood, and proliferative (severe), where unstable new blood vessels grow in the retina. In Jordan and the broader Middle East, approximately 30-40% of diabetic patients experience some degree of diabetic retinopathy, especially those with poor blood sugar control.

The primary cause is chronic elevated blood sugar that damages the walls of tiny blood vessels, causing leaks, scarring, and bleeding. Factors that accelerate the disease include diabetes duration, poor glucose control, high blood pressure, and elevated cholesterol levels.

In early stages, patients may have no symptoms, making regular screening essential. As the disease progresses, vision deteriorates gradually. Pregnant women with diabetes may notice rapid symptom progression.

• Floaters: Black spots or gray threads floating across the field of vision.
• Flashes of light: Sudden bright flashes, especially in peripheral vision.
• Blurry vision: Gradual blurring of sharp vision that may fluctuate.
• Difficulty with night vision: Trouble driving at night or seeing in dark areas.
• Eye pain: May occur in advanced stages or with elevated eye pressure.
• Eye redness: Noticeable redness indicating bleeding or inflammation.
• Difficulty distinguishing colors: Impaired perception of bright colors.
• Sensitivity to bright light: Discomfort in intense illumination.
• Gradual loss of vision areas: Portions of the visual field may disappear painlessly.
• Difficulty reading small text: Despite correct eyeglasses.

• Uncontrolled chronic diabetes: Persistently high blood sugar weakens the walls of tiny retinal blood vessels.
• Duration of diabetes: The longer the diabetes, the higher the risk of retinopathy developing.
• High blood pressure: Elevated pressure strains already-weakened vessel walls.
• High cholesterol and lipids: Accelerate vessel damage and increase leakage.
• Pregnancy in diabetic women: Can cause rapid progression during gestation.
• Smoking: Weakens blood vessels and reduces oxygen supply to the retina.
• Poor diet and obesity: Make blood sugar and blood pressure control more difficult.

• Long diabetes duration (>10 years): Risk increases with each year of disease.
• Poor glycemic control (HbA1c >8%): Reflects long-term failure to control blood sugar.
• Chronic high blood pressure: Pressure >140/90 mmHg doubles the risk.
• Diabetic kidney disease: Increases severity of blood vessel damage.
• Pregnancy and hormonal changes: Accelerate disease progression in women.
• Physical inactivity: Makes blood sugar and weight control harder.
• Family history: Having relatives with diabetes and retinopathy.
• Race and ethnicity: People of African and Asian descent have higher risk.
• Smoking and substance use: Damage blood vessels further.
• Poor medication adherence: Not taking diabetes and blood pressure medications regularly.

Diagnosis relies on comprehensive eye examination by a retina specialist or ophthalmologist. All diabetic patients should undergo annual eye exams, or more frequently if they have risk factors or symptoms.

• Visual Acuity Test: Measures sharpness of vision using the Snellen Chart.
• Ophthalmoscopy: Direct examination of the retina using a special magnifying lens to look for bleeding, swelling, or scars.
• OCT (Optical Coherence Tomography): High-resolution 3D imaging of the retina layers, detecting edema (fluid accumulation) with precision.
• Fundus Photography: Color photos of the fundus documenting hemorrhages or scars.
• Fluorescein Angiography: Dye is injected intravenously, then images reveal blood flow and vessel leakage.
• Tonometry: Measures eye pressure; elevated readings (>21 mmHg) may occur in advanced cases.
• Blood glucose and HbA1c testing: Blood tests revealing glycemic control level (goal <7%).

Medications

• Anti-VEGF injections (Avastin, Lucentis, Eylea): Injected directly into the eye to stop abnormal blood vessel growth and leakage. Given every 4-6 weeks as needed.
• Steroid injections (dexamethasone, triamcinolone): Reduce inflammation and macular edema (fluid accumulation).
• ACE inhibitors and beta-blockers: Oral medications that control blood pressure and protect blood vessels.
• Diabetes medications: Metformin, sulfonylureas, and newer agents (GLP-1 agonists) improve glycemic control.

Procedures and Surgery

• Laser photocoagulation: Focused laser beam burns damaged tissue to stop leakage and bleeding. Performed in clinic under local anesthesia, highly effective in early stages.
• Vitrectomy: Surgery removing blood-filled or scarred vitreous gel from inside the eye. Necessary in advanced cases with severe bleeding.
• Membrane peeling: Removes scars and membranes pulling on the retina.
• Silicone oil injection: Fills the space where vitreous was removed, supporting the retina during healing.

Lifestyle Changes

• Strict blood sugar control: Keep HbA1c <7% (ideally <6.5%), check blood sugar daily, take medications consistently.
• Blood pressure management: Target <130/80 mmHg through medication, exercise, and reduced salt.
• Regular physical activity: 150 minutes of moderate exercise weekly improves insulin sensitivity.
• Healthy nutrition: Avoid refined sugars and starches; prioritize vegetables, fiber, and protein.
• Quit smoking and alcohol: Smoking accelerates disease progression.
• Regular screenings: Annual eye exams minimum; regular blood glucose, pressure, and cholesterol checks.
• Maintain healthy weight: Losing 5-10% of body weight significantly improves glucose control.
• Manage psychological stress: Chronic stress elevates blood sugar and pressure.

• Macular edema: Fluid accumulation in the macula (sharp vision area), causing severe blurriness and potential blindness if untreated.
• Vitreous hemorrhage: Bleeding from diseased vessels into the vitreous gel, causing sudden darkening or total vision loss.
• Retinal detachment: The retina peels away from the eye wall due to strong scars or tissue shrinkage, causing permanent vision loss.
• Secondary glaucoma: Elevated eye pressure from blocked drainage channels by abnormal new vessels.
• Cataract: Clouding of the natural lens, develops earlier in diabetic patients.
• Permanent blindness: Can occur if complications go untreated; one of the leading causes of blindness in adults.
• Severe night vision impairment: Reduces quality of life and ability to drive and work.

• Tight blood sugar control: Take diabetes medications consistently, maintain HbA1c <7%, check blood glucose daily, especially before and after meals.
• Blood pressure management: Take antihypertensive medications regularly, target <130/80 mmHg.
• Regular eye screening: Visit an ophthalmologist or retina specialist at least annually, or every 3-6 months if symptomatic or high-risk.
• Regular physical activity: 150 minutes of moderate exercise weekly (brisk walking, swimming, cycling).
• Healthy balanced diet: Avoid sugar, sweets, and refined starches; eat vegetables, fruits, and lean proteins.
• Quit smoking: Smoking significantly increases risk.
• Maintain healthy weight: Obesity makes glucose control harder.
• Manage stress: Chronic stress elevates blood sugar and blood pressure.
• Adhere to screening schedules: Regular checks of blood glucose, pressure, and cholesterol.
• Health education: Learn diabetes symptoms and complications; prioritize early detection.