Diabetic Retinopathy: Why the First Warning Sign Is Often Blindness

India has the second-highest number of diabetics in the world — over 77 million and rising. Among them, approximately one-third will develop diabetic retinopathy (DR) during their lifetime, and a small but significant proportion will progress to visually disabling disease. The most sobering fact is this: diabetic retinopathy causes absolutely no symptoms in its early stages. Many patients assume that because they can see normally, their eyes must be fine. That assumption can cost them their vision.

How Diabetes Damages the Eye

The retina — the light-sensitive film at the back of the eye — is supplied by a dense network of very small blood vessels (capillaries). Persistently elevated blood glucose glycates the proteins in blood vessel walls, weakening them progressively over time. This leads to:

• Microaneurysms — tiny balloon-like swellings in capillary walls; the earliest visible sign
• Haemorrhages — bleeding from weakened vessels into the retinal layers
• Hard exudates — protein and lipid deposits that leak from damaged vessels
• Macular oedema — fluid accumulation in the macula (central retina) causing central vision blurring
• Neovascularisation — the ischaemic retina releases VEGF, stimulating growth of new fragile blood vessels that are prone to breaking and causing vitreous haemorrhage
• Tractional retinal detachment — scar tissue from new vessel proliferation pulls the retina away from the eye wall

Who Is At Greatest Risk?

All diabetics are at risk, but these factors accelerate progression significantly:

• Duration of diabetes — the single most important risk factor; after 20 years of Type 1 diabetes, almost all patients have some degree of retinopathy
• Poor glycaemic control — every 1% rise in HbA1c multiplies the risk of progression
• Hypertension — raises intraocular capillary pressure and accelerates vessel breakdown
• Renal disease — diabetic nephropathy and retinopathy share the same microvascular pathology
• Dyslipidaemia — hard exudates and macular oedema are more severe with elevated LDL and triglycerides
• Pregnancy in diabetic women — third trimester can cause rapid progression; requires monitoring every trimester
• Anaemia — worsens retinal ischaemia

How We Screen and Stage Disease

At Zala Clinic, diabetic eye screening follows international protocols:

• Dilated fundus examination — essential; cannot be replaced by undilated assessment
• Fundus photography — baseline image documents the retina's state for serial comparison
• Optical Coherence Tomography (OCT) — detects subclinical macular oedema invisible to clinical examination
• Frequency: annually for no retinopathy; every 6 months for mild NPDR; every 3 months for moderate-severe NPDR; monthly for active PDR or DMO on treatment

Treatment by Stage

Treatment is matched to disease severity:

• No / mild NPDR — optimise systemic control; annual review
• Moderate NPDR — tighter HbA1c and BP targets; 6-monthly review; consider statin for dyslipidaemia
• Severe NPDR / early PDR — pan-retinal photocoagulation (PRP laser) to reduce neovascular stimulus
• Diabetic Macular Oedema (DMO) — intravitreal anti-VEGF injections (Ranibizumab or Bevacizumab) are first-line; laser used in selected cases
• Advanced PDR / vitreous haemorrhage — vitreoretinal surgery (vitrectomy) referral

The Prevention Message

The landmark DCCT and UKPDS trials showed that tight glycaemic control (HbA1c < 7%) reduces the risk of developing retinopathy by 76% and its progression by 54% in Type 1 and Type 2 diabetes respectively. This is one of the most powerful preventive results in all of medicine. Regular eye reviews, combined with good systemic diabetes management and blood pressure control, mean that most patients with diabetes will never lose their vision — but only if they attend for screening.

If you have diabetes and have not had a dilated eye examination in the past year — or if you have any blurring, floaters, or dark spots — book an appointment with Dr. Mala R. Zala today. Early detection changes everything.