Diabetic retinopathy is the leading cause of preventable blindness among working-age adults. It develops silently, often without symptoms in the early stages — which is why regular eye exams matter so much for anyone with type 1 or type 2 diabetes.
How Diabetes Affects the Retina
High blood sugar damages the tiny blood vessels of the retina over time. The vessels weaken, leak fluid, or close off entirely. The body responds by growing new, fragile vessels that can bleed into the eye — a stage called proliferative retinopathy. By this point, vision loss may already be permanent.
The Four Stages
- Mild non-proliferative — small balloon-like swellings in retinal vessels. Often no symptoms.
- Moderate non-proliferative — vessels begin to close. Some blurring possible.
- Severe non-proliferative — more vessels close, depriving the retina of blood supply.
- Proliferative — new fragile vessels grow. High risk of bleeding and detachment.
Early Warning Signs
Floaters that suddenly appear, blurred or fluctuating vision, dark spots or empty areas in vision, difficulty seeing in low light, and trouble perceiving colors. Any of these warrant an urgent ophthalmologist visit.
Prevention and Slowing Progression
The single most important factor is blood sugar control. Studies show tight glucose management can reduce the risk of diabetic retinopathy by up to 76%. Equally important: controlling blood pressure and cholesterol. Annual dilated eye exams catch problems early, often before any noticeable vision change.
Treatment Options
Once retinopathy progresses, treatment options include laser photocoagulation (sealing leaking vessels), anti-VEGF injections (slowing new vessel growth), and in severe cases, vitrectomy surgery. Treatment can prevent further loss but rarely restores lost vision — which is why early detection is everything.
The American Academy of Ophthalmology offers an excellent overview of diabetic retinopathy with images and patient stories.