Diabetic Macular Edema, or DME, is the swelling of the macula — the central part of the retina responsible for sharp vision — due to fluid leaking out of damaged blood vessels in diabetes. It is the most common cause of vision loss in people with diabetes, and can occur at any stage of diabetic retinopathy, even mild.

What Happens Inside the Eye

In diabetes, tiny blood vessels in the retina become leaky. When the leak occurs at the macula, fluid accumulates between the layers of the retina — just like a sponge swelling with water. The macula thickens, the photoreceptors stop working normally, and the centre of your vision goes blurry or distorted. The longer this swelling lasts, the more permanent the damage.

DME vs. Diabetic Retinopathy — What’s the Difference?

Diabetic retinopathy is the umbrella term for all diabetes-related damage to the retinal blood vessels. DME is a specific complication — fluid leaking into the macula. DME can occur at any stage of diabetic retinopathy, even mild. Some patients with severe diabetic retinopathy never develop DME; others develop DME early. They are followed and treated as two related but separate conditions.

Symptoms

• Blurring of central vision — especially for reading or screens
• Distorted or wavy straight lines (metamorphopsia)
• Reduced contrast — colours look faded or “washed out”
• Difficulty reading small print, even with the right glasses
• A central blur or smudge that does not go away with blinking
• Peripheral (side) vision is usually preserved

Who Is at Risk?

• Long duration of diabetes
• HbA1c above 7.5%
• High blood pressure
• High cholesterol and triglycerides
• Kidney disease related to diabetes
• Pregnancy
• Recent cataract surgery (in diabetic eyes)

How We Diagnose DME

• Dilated retinal examination — the first step
• OCT (Optical Coherence Tomography) — the cornerstone test. A non-contact scan that measures the exact thickness of the macula and shows the fluid pockets
• OCT-Angiography — shows damage to the macular capillaries without dye
• Fluorescein angiography — when leakage patterns need to be mapped
• Fundus photography — to document hard exudates and bleeds over time

Types of DME We Treat

• Centre-involved DME (CI-DME) — fluid involves the foveal centre. Threatens vision more, treated more aggressively.
• Non-centre-involved DME — fluid present but the foveal centre is spared. May be observed or treated with focal laser.

Treatment Options

• Strict diabetic control — HbA1c, blood pressure, lipids and kidney function. Foundation of every treatment.
• Intravitreal anti-VEGF injections (Bevacizumab, Ranibizumab, Aflibercept, Brolucizumab, Faricimab) — first-line for centre-involving DME.
• Intravitreal steroids (Ozurdex implant, intravitreal triamcinolone) — for resistant cases, pseudophakic eyes, or when frequent visits are difficult.
• Focal or micropulse laser — for non-centre-involved DME, persistent leaks, or as add-on therapy.
• Vitrectomy surgery — rarely, for tractional DME or thick pre-macular membranes.

What to Expect from Treatment

• Most patients need multiple injections — typically 5–7 in the first year.
• Vision gains are gradual, often over 3–6 months.
• Strict diabetic control speeds recovery and reduces recurrence.
• Follow-up is lifelong — even when the eye is dry, the disease can return.
• The earlier we start treatment, the better the final vision.

Prevention & Self-Care

• HbA1c below 7% wherever safely possible
• Blood pressure below 140/90 mmHg
• LDL cholesterol controlled
• Quit smoking
• Regular dilated eye exams — annually for type 2 diabetes; within 5 years for type 1; each trimester in pregnancy
• Amsler grid at home for self-monitoring

When to Come to Us Immediately

Sudden drop in vision, new floaters, central distortion that has worsened, or a dark spot in the centre of your vision — come the same day.