Overview
Persistently high blood sugar weakens the tiny blood vessels feeding the retina. They leak, close off, and eventually trigger the growth of fragile new vessels that bleed. This is diabetic retinopathy, and it is a leading cause of sight loss in working-age adults.
The critical fact is that early retinopathy causes no symptoms whatsoever. Vision is normal right up until it is not. Annual dilated screening exists precisely because you cannot feel this coming.
What are the common symptoms?
- Nothing at all in the early stages
- Later: blurred or fluctuating vision
- Floaters or dark streaks from bleeding into the eye
- Dark or empty areas in vision
- Difficulty with colour
- Sudden vision loss if a large bleed or a detachment occurs
What causes it, and who is at risk?
- Duration of diabetes — the longer you have had it, the higher the risk
- Poor blood sugar control, and a high HbA1c
- High blood pressure and high cholesterol
- Pregnancy, which can accelerate progression
- Smoking, and kidney disease
How is it treated?
Systemic control is the foundation; eye treatments handle what control alone cannot.
- Annual dilated screening, without exception
- Tight control of blood sugar, blood pressure and cholesterol — this slows progression more than anything done to the eye
- Anti-VEGF injections for macular oedema, now the mainstay
- Laser photocoagulation for proliferative disease
- Vitrectomy surgery for persistent bleeding or traction detachment
When to get seen quickly
A sudden shower of floaters, a curtain across your vision, or sudden loss of sight in a diabetic eye needs same-day assessment.
This page is general information, not a diagnosis. Only an eye care professional who has examined you can tell you what is actually going on.