Diabetic and hypertensive retinopathy
- Lesion
Diabetes and high blood pressure damage the retina's small vessels, causing leakage, bleeding and new fragile vessels that can blind.
What it is
The retina is the one place where doctors see small vessels directly, and it shows the damage of diabetes and hypertension. In diabetes, thickened basement membranes and loss of pericytes weaken capillaries, which form microaneurysms, leak and close. Ischemic retina releases VEGF, driving new vessels that bleed and scar (proliferative retinopathy). Hypertension causes arteriolosclerosis with narrowed arterioles and nicking, and in severe or malignant hypertension, fibrinoid necrosis, hemorrhages, cotton-wool spots and disc swelling.
Step by step
- Chronic hyperglycemia forms advanced glycation end products and activates the polyol pathway.
- Capillary basement membranes thicken and pericytes die.
- Weakened walls bulge into microaneurysms and leak, causing edema and exudates.
- Capillaries close; retina becomes ischemic and releases VEGF.
- New fragile vessels grow on the retina and disc and into the vitreous.
- They bleed and contract, causing vitreous hemorrhage and tractional detachment.
Diabetic vs hypertensive retinopathy
| Feature | Diabetic retinopathy | Hypertensive retinopathy |
|---|---|---|
| Main vessel lesion | Capillary basement membrane thickening, pericyte loss | Arteriolosclerosis (hyaline or hyperplastic) |
| Typical early sign | Microaneurysms | Arteriolar narrowing and nicking |
| Hemorrhages | Dot and blot (deep) | Flame-shaped (nerve fibre layer) |
| Severe stage | Neovascularisation, vitreous bleeding, traction | Fibrinoid necrosis, exudates, disc edema |
| Driver | Hyperglycemia, VEGF from ischemia | Pressure injury to arterioles |
Clinical notes
- Regular fundus screening finds retinopathy before symptoms; a Latin American meta-analysis shows that retinopathy is common among people with diabetes in the region.
- Anti-VEGF injections and laser treat macular edema and proliferative disease; control of glucose and pressure slows progression.
Test yourself
Think of the answer, then tap the question to see it.
What is the earliest histologic change in diabetic retinopathy?
Thickening of the capillary basement membrane with loss of pericytes.
What is a cotton-wool spot?
A microinfarct of the nerve fibre layer where blocked axoplasmic flow swells axons (cytoid bodies).
Which growth factor drives proliferative diabetic retinopathy?
VEGF, released by ischemic retina.
Elsewhere in DurgiPedia
- Diabetes and the eye: screening and grading
- Hypertension and the eye
- Intravitreal anti-VEGF injections
- Blood supply of the retina and choroid
Connections
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Diabetic Retinopathy (StatPearls (NCBI Bookshelf), 2026); High blood pressure and eye disease: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Prevalence and incidence of diabetic retinopathy in patients with diabetes of Latin America and the Caribbean: A systematic review and meta-analysis (Europe PMC, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.