Diabetic Retinopathy
What is diabetic retinopathy?
Diabetic retinopathy (DR) is a diabetes-related eye disease caused by damage to the small blood vessels of the retina due to prolonged high blood sugar levels. It can affect people with both Type 1 and Type 2 diabetes and may lead to vision loss if left untreated.
The early stages often have no symptoms, making regular eye examinations essential.
Why does it occur?
Long-term high blood sugar damages the retinal blood vessels, leading to leakage of fluid and blood into the retina, reduced oxygen supply to retinal tissue, retinal swelling (macular oedema), and the growth of abnormal new blood vessels (neovascularisation).
The risk increases with:
- Longer duration of diabetes
- Poor blood sugar control
- High blood pressure
- High cholesterol levels
- Kidney disease
- Obesity
- Smoking
- Pregnancy
- Family history of diabetes-related eye disease
Types of diabetic retinopathy
Non-proliferative diabetic retinopathy (NPDR)
This is the early stage of diabetic retinopathy. Changes may include:
- Microaneurysms
- Retinal haemorrhages
- Hard exudates
- Cotton wool spots
- Venous abnormalities
Severe NPDR carries a higher risk of progression to advanced disease.
Proliferative diabetic retinopathy (PDR)
This advanced stage occurs when abnormal new blood vessels grow on the retina or optic nerve.
Possible complications include:
- Vitreous haemorrhage
- Fibrovascular proliferation
- Tractional retinal detachment
- Neovascular glaucoma
- Severe vision loss
Diabetic macular oedema (DME)
Diabetic macular oedema is the most common cause of vision loss in people with diabetes and can occur at any stage of diabetic retinopathy.
It develops when damaged retinal blood vessels leak fluid into the macula, the part of the retina responsible for detailed central vision.
Symptoms include:
- Blurred central vision
- Distorted images
- Difficulty reading
- Reduced contrast sensitivity
Symptoms of diabetic retinopathy
Early diabetic retinopathy often causes no symptoms.
As the disease progresses, patients may experience:
- Blurred vision
- Fluctuating vision
- Floaters
- Distorted vision
- Reduced colour perception
- Poor night vision
Advanced disease may cause sudden, painless vision loss due to vitreous haemorrhage or retinal detachment.
How is diabetic retinopathy diagnosed?
A comprehensive eye examination may include:
- Dilated fundus examination
- Fundus photography
- Optical coherence tomography (OCT)
- Fluorescein angiography (FFA)
- OCT angiography (OCTA)
Treatment
Control of diabetes and other risk factors
Good control of blood sugar, blood pressure, and cholesterol can significantly reduce the risk of disease progression.
Smoking cessation and treatment of associated medical conditions are equally important.
Laser treatment
Focal or grid laser is used in selected cases of diabetic macular oedema.
Panretinal photocoagulation (PRP) is the standard treatment for proliferative diabetic retinopathy. It reduces abnormal blood vessel growth and lowers the risk of severe vision loss.
Vitrectomy surgery
Vitrectomy surgery may be required for:
- Non-clearing vitreous haemorrhage
- Tractional retinal detachment
- Combined retinal detachment
- Severe fibrovascular proliferation
Anti-VEGF injections
Anti-VEGF injections are the first-line treatment for centre-involving diabetic macular oedema.
Commonly used medications include:
- Ranibizumab
- Aflibercept
- Bevacizumab
- Faricimab
These medications reduce retinal swelling and help improve vision.
Intravitreal steroid injections
Steroids, such as triamcinolone or dexamethasone implants, may be used in selected patients, particularly when diabetic macular oedema does not respond adequately to other treatments.
Prognosis
The outlook for diabetic retinopathy has improved significantly with modern treatments such as anti-VEGF injections, laser therapy, and vitreoretinal surgery.
However, advanced disease may still result in permanent vision loss due to:
- Macular ischaemia
- Chronic macular oedema
- Retinal detachment
Early detection and timely treatment offer the best chance of preserving vision.
Screening recommendations
People with diabetes should undergo retinal examinations every six months, even if their vision appears normal, as diabetic retinopathy often develops without symptoms.
Regular screening helps detect the disease early and prevents avoidable vision loss.
Diabetic retinopathy is a leading cause of preventable blindness. However, early detection, good diabetes control, regular eye screening, and timely treatment can help protect your vision.
Don’t wait for symptoms. Schedule regular retinal check-ups and protect your sight for life.