Diabetes and Your Eyes: Why Annual Screening Matters

Diabetic retinopathy is the leading cause of preventable blindness in working-age adults, and its cruelty lies in being painless and symptom-free until significant damage is done.

What happens to the retina

Persistently high blood sugar damages the tiny blood vessels supplying the retina. They leak, then close off, and the starved retina responds by growing fragile new vessels that bleed into the eye. By the time vision blurs, the disease is usually well established.

The screening schedule

• Type 2 diabetes: a dilated retinal examination at diagnosis, then annually.
• Type 1 diabetes: starting five years after diagnosis, then annually.
• In pregnancy: screening each trimester, as retinopathy can progress quickly.

What screening involves

Drops dilate the pupil, and the retina is examined and photographed. Where needed we add optical coherence tomography (OCT) to measure macular swelling and fundus fluorescein angiography (FFA) to map leaking vessels. The visit takes about an hour, most of it waiting for the drops to work.

Treatment

Early disease needs no treatment beyond good glycaemic and blood-pressure control. More advanced disease is treated with retinal laser, intravitreal anti-VEGF injections, or vitrectomy surgery where there is bleeding or tractional detachment.

The single most useful thing you can do

Book the annual examination even when your vision feels perfect. That is precisely the point at which treatment works best.