Diabetes accelerates cataract — both the typical age-related opacity and the disabling posterior subcapsular cataract often seen in younger diabetics. The cataract surgery itself is technically the same as in non-diabetics, but the surrounding care is different. Diabetic eyes need extra protection before, during and after surgery to safeguard the retina, manage healing and deliver the best possible vision outcome. With over 100 million Indians now living with diabetes, this is a routine but specialised part of our cataract practice.

Why Diabetic Cataract Surgery Is Different

• The retina may be quietly affected. Diabetes can cause non-proliferative retinopathy, proliferative retinopathy and diabetic macular oedema (DME) — sometimes without symptoms. A cataract can hide all of these.
• Cataract surgery can unmask or worsen retinopathy. The post-operative inflammation can trigger or aggravate macular oedema in eyes already at risk.
• Healing is slower. Corneal recovery, wound sealing and pupil dilation can all be sluggish in long-standing diabetes.
• Pseudoexfoliation, neovascular glaucoma and zonular weakness are more common, all of which need surgical adjustments.

Pre-operative Assessment

1. Detailed Retinal Examination

Every diabetic patient receives a dilated fundus examination at the cataract assessment, looking for:

• Microaneurysms, dot & blot haemorrhages, hard exudates
• Cotton-wool spots and venous changes (suggesting active retinopathy)
• Neovascularisation at the disc or elsewhere (proliferative disease)
• Macular oedema (often subtle and best confirmed on OCT)

2. Macular OCT

Macular OCT is mandatory before cataract surgery in diabetic patients. It detects:

• Diabetic macular oedema
• Epiretinal membrane
• Subtle structural macular damage
• Co-existing ARMD (in older patients)

Any active macular oedema is treated with anti-VEGF injections or laser before cataract surgery so the macula is dry on the day of surgery.

3. Wide-field Fundus Photography or FFA

If proliferative retinopathy is suspected, fundus fluorescein angiography (FFA) or wide-field imaging guides whether laser pan-retinal photocoagulation is needed before cataract surgery.

4. Glycaemic Optimisation

We aim for:

• Fasting blood sugar < 140 mg/dL on day of surgery
• HbA1c ideally < 7.5–8%
• BP well controlled — uncontrolled hypertension worsens diabetic retinopathy
• Renal function checked when on metformin or anti-diabetic drugs that affect kidneys

Surgery is rarely deferred for sugar levels alone, but obviously uncontrolled hyperglycaemia is best stabilised first to reduce wound healing and infection risk.

Surgical Considerations

The surgeon adapts the technique in diabetic eyes:

• Smaller capsulorhexis minimises post-operative capsular shrinkage common in diabetic eyes
• Gentler phaco settings reduce inflammation and protect a sometimes-weaker zonular apparatus
• Pupil expansion devices may be needed if the pupil dilates poorly
• Iris protection in eyes with neovascularisation
• In-the-bag IOL placement is the rule, with capsular tension ring used if zonular weakness is suspected
• Intracameral cefuroxime at the end of surgery — endophthalmitis prevention is especially important in diabetics

IOL Choice in Diabetic Patients

Healthy macula, no retinopathy

Premium IOLs (trifocal, EDOF) are reasonable. Toric versions are added if there is significant astigmatism. The patient should understand that future macular disease may reduce the IOL’s effective performance.

Mild non-proliferative retinopathy, no maculopathy

EDOF or high-quality monofocal IOL preferred. Trifocals are usually avoided because their split-light optics may aggravate any future macular disease.

Proliferative retinopathy or maculopathy

High-quality monofocal IOL (toric if needed). The priority is the best possible image quality so the retina specialist can see and treat the retina effectively long-term. Premium IOLs are not recommended.

Post-operative Care

Post-op care in diabetics is more intensive than in non-diabetics:

• Anti-inflammatory drops — typically a steroid drop plus an NSAID drop, continued longer (6 weeks) to prevent diabetic macular oedema
• OCT at 4–6 weeks post-op to detect early post-op macular oedema
• Regular retinal review for 3–6 months — even if everything looks fine immediately
• Tight glycaemic and blood-pressure control after surgery is part of the long-term protection of vision

Long-term Vision Outcomes

Most diabetic patients achieve excellent vision after cataract surgery — often dramatically better than they expected. The factors that most strongly predict the final result are:

• The state of the macula (best predictor by far)
• The level of pre-existing retinopathy
• Long-term glycaemic and blood-pressure control
• Adherence to follow-up — diabetic eyes need lifelong screening

Frequently Asked Questions