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Role and principlesAssessment and patient selectionBaseline assessmentInterventionsMedicines and treatment safetyTargets, monitoring and follow-upSpecial situationsCommon pitfallsQuestionsSources
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Educational draft · awaiting clinical reviewThe full textbook explains uncertainty but does not replace live national or local guidance, specialist advice, or current prescribing information.

Diabetic retinopathy screening and treatment

Endocrinology and metabolism · UK scope · Sources checked 27 Aug 2026 · Clinical review pending

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Time-critical presentation

Sudden painless visual loss, a new shower of floaters, flashes with a curtain or field defect, painful red eye after an intravitreal procedure, or rapid visual change in pregnancy needs urgent same-day ophthalmic assessment. Do not wait for the next diabetic eye-screening appointment.

Role and principles

Detect sight-threatening diabetic retinal disease before vision is lost, distinguish screening from diagnostic eye care, and coordinate timely ophthalmic treatment while improving systemic risk safely.

Chronic hyperglycaemia damages retinal capillaries through leakage, occlusion and ischaemia. Early non-proliferative change may remain asymptomatic; increasing ischaemia stimulates vascular endothelial growth factor, causing fragile new vessels, vitreous bleeding and fibrovascular traction. Separately, breakdown of the blood-retinal barrier causes macular oedema and loss of detailed central vision. Disease severity in each eye, macular involvement and visual function guide urgency and treatment.

The care pathway has two linked but distinct functions. Population screening uses retinal images and quality-assured grading to identify people who need surveillance or referral. Hospital eye services confirm disease with dilated examination and optical coherence tomography, sometimes fluorescein angiography, and decide on laser, intravitreal therapy or surgery. A person with symptoms must enter diagnostic eye care immediately even if their last screening result was reassuring.

The central decision is whether retinal disease is absent or safely surveilled, referable for specialist review, or already sight threatening and requiring prompt intervention. Interpretation must include pregnancy, kidney disease, blood pressure, speed of glucose improvement, ability to attend, and whether media opacity made screening images ungradable.

Assessment and patient selection

No visual symptoms

Early diabetic retinopathy commonly preserves acuity, so feeling that eyesight is normal is not a reason to decline screening or delay a referable appointment.

Non-proliferative change

Microaneurysms, dot or blot haemorrhages, hard exudates, venous change and intraretinal microvascular abnormalities indicate increasing retinal vascular injury before new vessels appear.

Proliferative diseaseRed flag

New vessels at the disc or elsewhere, preretinal haemorrhage, vitreous haemorrhage or fibrous proliferation signals high risk of severe sight loss and needs timely ophthalmic treatment.

Macular oedemaRed flag

Blurred or distorted central vision and difficulty reading may accompany centre-involving retinal thickening, although optical coherence tomography can find clinically important oedema before prominent symptoms.

Vitreous haemorrhageRed flag

Sudden painless haze, cobwebs, spots or marked loss of vision in an eye with proliferative disease can represent bleeding from fragile neovascular tissue and warrants urgent assessment.

Tractional detachmentRed flag

A curtain, missing field, distortion or progressive visual loss may reflect fibrovascular traction threatening or involving the macula; vitreoretinal review must not await screening recall.

Post-procedure endophthalmitisRed flag

Baseline assessment

  1. 01
    Quality-assured retinal photographyFirst step
    Why
    Screen eligible asymptomatic people for diabetic retinal and macular abnormalities.
    Interpretation and limitations
    Check image quality and the programme grade for each eye. An ungradable result is not a negative screen and should trigger the local alternative assessment pathway rather than routine recall.
  2. 02
    Best-corrected visual acuity
    Why
    Quantify functional effect and provide a baseline for treatment response.
    Interpretation and limitations
    Reduced acuity may result from macular oedema, cataract or another eye disorder, while normal acuity does not exclude proliferative peripheral disease; interpret alongside retinal findings.
  3. 03
    Dilated slit-lamp fundus examination
    Why
    Confirm screening abnormalities and inspect the retina, macula, disc and vitreous directly.
    Interpretation and limitations
    The ophthalmologist looks for new vessels, haemorrhage, traction, exudation and alternative pathology and assigns a clinical stage that can differ from the screening label.
  4. 04
    Optical coherence tomography
    Why
    Map retinal thickness and fluid at the macula non-invasively.
    Interpretation and limitations
    Centre involvement, structural change and serial response help select observation, laser or intravitreal therapy. An OCT image complements rather than replaces clinical examination.

Interventions

01ScreenRoutine diabetic eye surveillanceFirst stepEligible person with diabetes who has no acute visual symptom requiring diagnostic assessment.+
  1. 1Confirm enrolment in the correct national programme, current contact details, accessibility needs and whether pregnancy or previous eye treatment changes the standard recall route.
  2. 2AlternativeExplain dilation, temporary blur and driving implications; obtain quality-assured retinal photographs and ensure ungradable images enter the alternative assessment pathway.
  3. 3Communicate the grade and next step in understandable language, distinguishing routine recall, closer surveillance and referral to hospital eye services.
  4. 4Use non-attendance as a safety problem: explore transport, language, disability, fear and deprivation barriers and apply local failsafe procedures rather than silently closing the episode.
02Refer

Medicines and treatment safety

Reduces vascular leakage and retinal thickening in eligible diabetic macular oedema and can suppress retinal neovascular activity.

Intravitreal anti-VEGF therapy

Administer by an ophthalmologist using the licensed loading and review schedule for the selected agent.

Requires repeated sterile intravitreal procedures and OCT-led response review. Counsel about endophthalmitis, inflammation and sudden vision change; pregnancy, recent vascular events and bilateral scheduling need individual specialist assessment.

Treats selected diabetic macular oedema when anti-VEGF response, suitability or treatment burden supports a steroid strategy.

Intravitreal corticosteroid implant

Use only the licensed ophthalmic implant and retreatment interval selected by the retinal service.

Can raise intraocular pressure and accelerate cataract; monitor pressure and lens, exclude infection and apply NICE eligibility rather than using it as routine first treatment.

Sustained improvement in glycaemia reduces long-term onset and progression of diabetic microvascular disease.

Systemic glucose-lowering treatment

Optimise the existing regimen gradually against the individual's diabetes target and retinal surveillance plan.

Do not delay necessary control, but warn ophthalmology when advanced retinopathy accompanies a rapid planned fall in glucose. Hypoglycaemia, pregnancy, CKD and treatment-specific harms determine the pace.

Targets, monitoring and follow-up

  • Track screening invitation, attendance, image grade, referral outcome and the next due date; programme failsafes should identify people lost between photography and hospital treatment.
  • After anti-VEGF or steroid treatment, monitor visual acuity and OCT anatomy at the retinal service interval, recording response, recurrence and injection burden rather than relying on HbA1c.
  • After retinal laser, assess regression of neovascularisation and complications, and give urgent instructions for new floaters, field loss or sudden deterioration.
  • Review HbA1c trajectory, blood pressure, smoking, renal function and albuminuria through diabetes care, with staged improvement that avoids hypoglycaemia and treatment abandonment.
  • During pregnancy, complete retinal reviews at NICE-defined points and escalate any progression jointly; do not assume a normal preconception image removes gestational risk.
  • Ask about functional vision, driving, work, falls, medication administration and mental health, referring to low-vision and social support when retinal damage changes daily life.

Special situations

Screening is not diagnosis

A photograph-based grade determines the next pathway. Treatment decisions require ophthalmic confirmation, visual assessment and often OCT, while symptoms may demand care before any grade exists.

Normal sight can conceal danger

Peripheral proliferative vessels can develop without central acuity loss. The purpose of screening is precisely to treat disease before the person notices it.

Ungradable is actionable

Cataract, small pupils or poor image capture can prevent a safe result. Repeatedly filing an ungradable image as reassuring delays both retinal and other ocular diagnosis.

Rapid improvement needs surveillance

Early worsening after a sharp glucose reduction is usually managed with closer retinal observation and treatment, not by abandoning beneficial long-term glucose control.

Kidney and eye risks cluster

Albuminuria and falling eGFR are markers of systemic microvascular burden. Finding one complication should prompt deliberate review for the other and for cardiovascular risk.

Laser and injection solve different problems

Panretinal laser reduces the ischaemic drive in proliferative disease, while intravitreal treatment commonly targets macular leakage; some eyes need both or later surgery.

National programmes vary

Eligibility, recall and grading terminology are commissioned separately across England, Scotland, Wales and Northern Ireland. Teach the principle and check the person's local programme rather than inventing a universal interval.

Common pitfalls

  1. 01

    Reassuring a symptomatic person because their last diabetic eye screen was normal.

  2. 02

    Treating an ungradable photograph as absence of retinopathy.

  3. 03

    Confusing diabetic eye screening with a refraction and routine sight test.

  4. 04

    Delaying ophthalmology referral while attempting to improve HbA1c first.

  5. 05

    Stopping needed glucose treatment because retinopathy can transiently worsen with rapid improvement.

  6. 06

    Assuming gestational diabetes alone requires the same screening pathway as pre-existing diabetes.

  7. 07

    Omitting urgent post-injection advice about pain, redness and reduced vision.

  8. 08

    Failing to close the loop after a referable result or repeated non-attendance.

Practice

Two practice questions

Your practice draft is saved in this browser.

Question 1 of 2
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Endocrinology and metabolismOriginal SBA

Sudden floaters after screening

A person with diabetes had background retinopathy at screening four months ago and now reports a sudden dense shower of floaters and painless reduction in one eye. What is the safest action?

Choose one answer, then submit
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Sources and review status5 sources · checked 27 Aug 2026 · clinical review pending+
Sources

Sources and review status

National guidance is shown before implementation-dependent detail. Typical adult dose examples remain subject to patient factors, contraindications and the live BNF or specialist protocol. Source check completed 27 Aug 2026; clinical approval remains outstanding.

  • NICE NG242 diabetic retinopathy recommendationsHospital assessment, surveillance and treatment of retinal disease and macular oedema.
  • NHS diabetic eye screening pathway standardsQuality and timeliness standards for the English screening pathway.
  • NHS diabetic eye screening pathway requirementsEligibility, screening, referral and failsafe requirements.
  • NICE NG3 diabetes in pregnancy recommendationsRetinal assessment before and during pregnancy with pre-existing diabetes.
  • Royal College of Ophthalmologists diabetic retinopathy guidance updateSpecialty context for the NICE diabetic retinopathy guideline.

Editorial contact: Doctor’s Passport editorial team. Source-check date is separate from clinical approval. Report a content problem ·

Key points

  • Diabetic eye screening detects retinal change in people who may still see normally; it does not replace a routine sight test or assessment of new visual symptoms.
  • The English programme invites eligible people with diabetes from age 12, excluding gestational diabetes alone; pathways and intervals differ across UK nations, so verify the local programme.
  • Background non-proliferative disease reflects microaneurysms, haemorrhages and exudates, whereas proliferative disease is defined by retinal or disc neovascularisation and threatens vitreous haemorrhage and tractional detachment.
  • Diabetic macular oedema threatens central vision through retinal thickening or fluid near the fovea and may require optical coherence tomography even when a photograph suggests only subtle change.
  • Referable screening findings trigger diagnostic ophthalmology assessment; a screening grade is a risk signal, not the final treatment diagnosis.
  • Panretinal photocoagulation remains core treatment for proliferative diabetic retinopathy, while anti-VEGF, focal or grid laser and selected steroid therapy are used for
Increasing pain, redness, photophobia and reduced vision after an intravitreal injection is an ophthalmic emergency because infectious endophthalmitis can destroy vision rapidly.
Pregnancy-associated progression

Pre-existing type 1 or type 2 diabetes, especially with established retinal disease or rapid glucose improvement, requires the pregnancy retinal pathway; gestational diabetes alone does not enter routine diabetic eye screening.

  • 05
    Wide-field imaging or fluorescein angiography
    Why
    Define peripheral ischaemia, leakage and neovascular activity when treatment planning needs greater detail.
    Interpretation and limitations
    Use only when the specialist result will change laser or diagnostic decisions; angiography has procedure-specific risks and is not a routine primary-care test.
  • 06
    HbA1c and glucose trajectory
    Why
    Assess chronic exposure and whether recent improvement may alter short-term retinal risk.
    Interpretation and limitations
    Sustained safer glucose reduces long-term progression, but a rapid fall in someone with advanced disease may precede transient worsening. Coordinate surveillance rather than deliberately maintaining harmful hyperglycaemia.
  • 07
    Blood pressure, eGFR and urine albumin-to-creatinine ratio
    Why
    Identify systemic microvascular and haemodynamic drivers that travel with retinopathy.
    Interpretation and limitations
    Hypertension, albuminuria and kidney decline strengthen the need for integrated cardiovascular and renal management and may affect procedure planning, but do not grade the retina themselves.
  • 08
    Pregnancy and treatment history
    Why
    Place the person on the correct surveillance and procedural pathway.
    Interpretation and limitations
    Record pre-existing versus gestational diabetes, gestation, previous laser or injections, anticoagulants and ability to attend. Do not stop antithrombotic treatment reflexively before an eye procedure; ophthalmology advises.
    • Referable retinopathy or maculopathy
    Screening shows proliferative features, significant non-proliferative change, maculopathy or repeated ungradable images.
    +
    1. 1Check for current visual loss, floaters, field defect or pain; symptoms can upgrade a routine referral to same-day ophthalmic assessment.
    2. 2Send the retinal grade, image quality, visual acuity, diabetes type, pregnancy status and previous treatment through the commissioned referral pathway.
    3. 3Hospital eye services confirm stage with dilated examination and OCT, adding angiography when it will guide intervention, and agree treatment urgency with the patient.
    4. 4Keep primary diabetes, kidney and blood-pressure care active while referral proceeds and verify that the appointment was received and attended.
    03TreatSight-threatening retinal diseaseConfirmed proliferative retinopathy, clinically significant macular oedema or another lesion meeting specialist treatment criteria.+
    1. 1AlternativeFor proliferative disease, offer panretinal photocoagulation within the NICE timeframe unless the ophthalmologist identifies a reason for an alternative or adjunctive approach.
    2. 2For diabetic macular oedema, use OCT, centre involvement, vision and retinal thickness to choose observation, focal or grid laser, anti-VEGF treatment or selected intravitreal steroid under current NICE guidance.
    3. 3DefinitiveDiscuss procedure burden, transient visual effects, injection infection warnings, pregnancy considerations and the importance of completing the course rather than treating one visit as definitive.
    4. 4Refer vitreous haemorrhage, macula-threatening traction or non-clearing disease for vitreoretinal assessment and vitrectomy when indicated, with rehabilitation support if sight is impaired.
    04PregnancyPre-existing diabetes retinal surveillancePregnancy in a person with type 1 or type 2 diabetes before conception or diagnosed as overt diabetes early in gestation.+
    1. 1Establish retinal status before conception where possible or promptly in early pregnancy and identify previous proliferative disease, laser, macular oedema or visual symptoms.
    2. 2Repeat assessment at the NICE-defined gestational points according to baseline findings and ensure rapid metabolic improvement is accompanied by eye surveillance.
    3. 3Coordinate ophthalmology, maternity and diabetes teams if disease progresses; pregnancy is not a reason to leave sight-threatening retinopathy untreated, although the procedure and medicine plan is specialist led.
    4. 4Return the person to the appropriate postnatal and long-term screening pathway, documenting completed treatment and any shortened recall interval.
    Content changes
    Authoring stateComplete draftClinical stateAwaiting reviewJurisdictionUnited Kingdom
    macular oedema
    according to NICE and ophthalmic assessment.
  • Pregnancy and rapid improvement of long-standing hyperglycaemia can temporarily accelerate retinopathy, so arrange surveillance rather than withholding necessary glucose treatment.
  • Control of blood pressure, glucose, kidney disease, lipids and smoking risk reduces progression, but systemic optimisation never substitutes for indicated laser, injection or vitreoretinal surgery.
  • New eye symptoms bypass routine screening: screening intervals are designed for asymptomatic surveillance and are unsafe as an emergency waiting list.