Diabetic retinopathy

Red Flags

Sudden vision loss or new floaters with diabetes — emergency ophthalmology; vitreous haemorrhage or tractional retinal detachment^[1]
Severe non-proliferative diabetic retinopathy (NPDR), proliferative DR, or diabetic macular oedema — same-week retinal specialist for laser, intravitreal therapy, or vitrectomy^[1]
Pregnancy with pre-existing diabetes — screen for DR at booking and each trimester; risk of rapid worsening^[1]
Severe hypoglycaemia or rapid HbA1c reduction in T1DM with established DR — treatment-induced retinopathy worsening^[1]

First-line treatment

Interventions

Glycaemic, BP, lipid control^[1]
HbA1c <7% reduces progression by ~76% per UKPDS; BP <130/80; statin therapy; coordinate with diabetes physician
Annual screening pathway^[1]
Population-level screening with digital fundus photography or telemedicine; trained reader or AI grading; refer to ophthalmology for any DR more advanced than mild NPDR or any maculopathy
Pan-retinal photocoagulation (PRP)^[1]
Proliferative diabetic retinopathy; severe NPDR in selected high-risk patients; multiple sessions; transient peripheral vision loss
Intravitreal anti-VEGF therapy^[1]
Diabetic macular oedema (centre-involving); high-risk PDR alternative or adjunct to PRP; ranibizumab, bevacizumab (off-label, cost-effective in low-resource settings), aflibercept, faricimab
Vitrectomy^[1]
Non-clearing vitreous haemorrhage, tractional retinal detachment, fibrovascular proliferation; often combined with PRP and intraoperative anti-VEGF

First-line drug therapy

Drug	Class	Adult	Paediatric	Notes
Bevacizumab (intravitreal — off-label, cost-effective)^[1]	Anti-VEGF monoclonal antibody	1.25 mg intravitreal monthly × 5 doses then variable	—	Cost-effective alternative widely used in resource-limited settings; off-label for ophthalmic use; comparable efficacy in Protocol T for moderate vision loss
Ranibizumab (intravitreal)^[1]	Anti-VEGF Fab fragment	0.5 mg intravitreal injection monthly × 4–5 doses then variable (PRN, treat-and-extend)	—	First-line ophthalmic-licensed anti-VEGF for centre-involving DME; specialist administration; monitor IOP, endophthalmitis risk
Aflibercept (intravitreal)^[1]	Anti-VEGF fusion protein	2 mg intravitreal monthly × 5 doses then every 8 weeks	—	Comparable efficacy to ranibizumab; longer durability allowing extended intervals
Intravitreal triamcinolone or dexamethasone implant (refractory DME)^[1]	Intravitreal corticosteroid	Triamcinolone 4 mg intravitreal; dexamethasone 0.7 mg sustained-release implant every 4–6 months	—	Refractory DME or anti-VEGF non-response; cataract progression and IOP rise; consider after multiple anti-VEGF failures or pseudophakic eye

Bevacizumab (intravitreal — off-label, cost-effective)^[1]

Anti-VEGF monoclonal antibody

Adult: 1.25 mg intravitreal monthly × 5 doses then variable
Paediatric: —

Cost-effective alternative widely used in resource-limited settings; off-label for ophthalmic use; comparable efficacy in Protocol T for moderate vision loss

Ranibizumab (intravitreal)^[1]

Anti-VEGF Fab fragment

Adult: 0.5 mg intravitreal injection monthly × 4–5 doses then variable (PRN, treat-and-extend)
Paediatric: —

First-line ophthalmic-licensed anti-VEGF for centre-involving DME; specialist administration; monitor IOP, endophthalmitis risk

Aflibercept (intravitreal)^[1]

Anti-VEGF fusion protein

Adult: 2 mg intravitreal monthly × 5 doses then every 8 weeks
Paediatric: —

Comparable efficacy to ranibizumab; longer durability allowing extended intervals

Intravitreal triamcinolone or dexamethasone implant (refractory DME)^[1]

Intravitreal corticosteroid

Adult: Triamcinolone 4 mg intravitreal; dexamethasone 0.7 mg sustained-release implant every 4–6 months
Paediatric: —

Refractory DME or anti-VEGF non-response; cataract progression and IOP rise; consider after multiple anti-VEGF failures or pseudophakic eye

Safety-net

Annual eye check is essential even when vision feels normal — diabetic retinopathy is silent until advanced^[1]
Sudden vision loss, new floaters, flashes, or sudden blurry vision — same-day ophthalmology assessment^[1]
Tight blood sugar and BP control slows progression; coordinate rapid HbA1c reductions with eye team^[1]

Referral criteria

Any DR more advanced than mild NPDR; any diabetic macular oedemaOphthalmology / retina specialist^[1]
Sudden vision loss, vitreous haemorrhage, tractional retinal detachment, neovascular glaucomaEmergency ophthalmology^[1]
Pregnancy with pre-existing diabetesScreen at booking and trimester progression^[1]
Failure of anti-VEGF or refractory DMETertiary retinal service for combined therapy or alternative agent^[1]

Clinical summary

Screening, staging, anti-VEGF, laser, and surgical pathway for diabetic retinopathy and diabetic macular oedema in adults with diabetes.

References

1.All India Ophthalmological Society Guidelines for Diabetic Retinopathy Screening (2023); AAO Diabetic Retinopathy Preferred Practice Pattern; ICO Guidelines for Diabetic Eye Care (2023)