Eyes & Vision

Diabetic retinopathy

Diabetes damages retinal microvasculature, progressing from non-proliferative disease to ischaemia-driven neovascularisation, while diabetic macular oedema is a separate sight-threatening pathway; screening and stage-specific ophthalmic treatment prevent avoidable visual loss.

In a nutshell

Diabetic retinopathy is usually silent early: screening detects non-proliferative disease before it threatens sight. Ischaemia drives VEGF and proliferative retinopathy, while diabetic macular oedema independently threatens central vision. Stage the disease, escalate urgent visual loss, and use NICE-directed laser, intravitreal or surgical treatment in hospital eye services.

Classic presentation

A person with diabetes is asymptomatic at screening with microaneurysms or haemorrhages, or develops gradual central blur from macular oedema or sudden floaters/visual loss from vitreous haemorrhage. Preserved visual acuity does not exclude proliferative disease.

Key points

Routine diabetic eye screening is distinct from a standard sight test; early retinopathy is often asymptomatic.
Non-proliferative disease reflects leakage and ischaemia; proliferative disease reflects ischaemia-driven neovascularisation and can bleed or detach the retina.
Diabetic macular oedema is assessed separately and may occur with or without proliferative retinopathy.
Sudden visual loss, rubeosis iridis, pre-retinal/vitreous haemorrhage or retinal detachment needs emergency ophthalmology review.
When a diabetes treatment is likely to cause a rapid, substantial HbA1c fall, notify ophthalmology and arrange eye assessment before and after the change.
Treat each eye according to its active pathology; do not assume both eyes have the same stage or treatment need.
Panretinal photocoagulation is usually offered when proliferative disease is first diagnosed; anti-VEGF and vitrectomy are specialist pathway decisions.
NICE recommends macular laser for non-centre-involving clinically significant oedema and uses vision plus central retinal thickness to guide centre-involving oedema treatment.

First-line investigation

Diabetic eye screening with visual acuity, dilating drops and retinal photography; if disease is referable or symptoms are present, proceed to ophthalmic examination and OCT where macular oedema is suspected.

Management

Recognise the eye emergency

Arrange emergency ophthalmology review for sudden visual loss, rubeosis iridis, pre-retinal/vitreous haemorrhage or retinal detachment; a painful red eye with high pressure is also urgent.^7,2,3

Confirm stage and macular involvement

Use the screening grade or hospital retinal examination, visual function, pressure assessment and OCT for suspected macular oedema; treat each eye separately.^1,6,3

Treat proliferative disease promptly

Offer panretinal photocoagulation at first diagnosis of proliferative disease, with anti-VEGF or vitreoretinal surgery in defined specialist situations.^1,2,4

Improve the modifiable risk environment

Coordinate long-term diabetes and blood-pressure care, share HbA1c/pressure/renal results with ophthalmology, and flag a planned rapid substantial HbA1c reduction.^1,7

Treat diabetic macular oedema by anatomy and vision

Offer treatment for clinically significant oedema; use macular laser for non-centre-involving disease and discuss observation, laser, anti-VEGF or steroid options for centre-involving disease according to vision and OCT findings.^1,2

Reassess after treatment and preserve the pathway

Assess proliferative regression 2 to 3 months after treatment, monitor treated disease under hospital eye services for 12 months, then discharge to screening only when eligibility criteria are met.^1,6,3

Exam traps

Normal visual acuity does not rule out proliferative diabetic retinopathy.
A standard optician sight test is not a substitute for the NHS diabetic eye screening programme.
Macular oedema and proliferative retinopathy are separate processes and can coexist.
Do not apply a routine screening interval to someone with active hospital-treated disease; follow the eye-service plan.
Rapid improvement in HbA1c can be associated with early worsening of retinopathy, so coordinate intensive diabetes treatment with ophthalmology.
Sudden visual loss in diabetes is an eye emergency until vitreous haemorrhage, retinal detachment and other acute causes have been assessed.

Illustrations

Progression from microvascular leakage to neovascularisationDiagram showing capillary damage leading to microaneurysms and leakage, then ischaemia, then VEGF-driven new vessel growth.PassFinals · original

Background diabetic retinopathy on fundoscopyColour fundus photograph showing clusters of hard exudates with scattered microaneurysms and small dot haemorrhages in background diabetic retinopathy.Shaofeng Hao, Changyan Liu, Na Li, Yanrong Wu, Dongdong Li, Qingyue Ga, Wikimedia Commons · CC-BY-4.0

Proliferative diabetic retinopathy with neovascularisationRetinal photograph showing abnormal new vessels at the optic disc with associated haemorrhage.Patho, Wikimedia Commons · Public domain

Key sources

This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.