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Diabetic retinopathy and diabetic macular oedema
Diabetic retinopathy is a small-vessel disease of the retina that progresses from a non-proliferative stage (NPDR) to a proliferative stage (PDR) with new vessels; vision is lost mainly from macular oedema (DME) — treated with anti-VEGF — and from vitreous haemorrhage and tractional detachment — treated with PRP and surgery.
Why it matters in the exam
The exam asks about classification and the treatment decision. Severe NPDR is defined by the 4-2-1 rule: haemorrhages in all 4 quadrants, venous beading in 2 quadrants or IRMA in 1 quadrant. PDR is defined by new vessels on the disc (NVD) or elsewhere (NVE), vitreous haemorrhage or tractional detachment. The DRS trial showed that PRP lowers the risk of severe visual loss in high-risk PDR by more than 50%.
In macular oedema the key distinction is centre involvement on OCT (centre-involving DME). When the centre is involved and vision has dropped, intravitreal anti-VEGF is first line (aflibercept, ranibizumab, bevacizumab, faricimab); Protocol T showed an advantage for aflibercept when acuity is 20/50 or worse. A dexamethasone implant suits a pseudophakic eye or resistant oedema, with a risk of raised pressure and cataract. Oedema that spares the centre — focal laser or observation. Protocol S showed anti-VEGF to be a reasonable alternative to PRP in PDR when follow-up can be assured.
Screening: in type 1 diabetes — 5 years after diagnosis and then yearly; in type 2 diabetes — at diagnosis, because disease is present for years before it is diagnosed; in pregnancy — before conception or in the first trimester, because retinopathy may worsen (not in gestational diabetes). With no retinopathy and good control every 1–2 years is acceptable. Accelerating factors: poor control, hypertension, kidney disease, pregnancy, and also a very rapid fall in HbA1c (early worsening). Fenofibrate slowed progression in the FIELD and ACCORD-Eye studies.
Key points
- NPDR → PDR with new vessels; DME is the commonest cause of reduced vision.
- Severe NPDR: the 4-2-1 rule.
- Centre-involving DME with reduced vision → anti-VEGF.
- High-risk PDR → PRP or anti-VEGF.
- Screening: type 1 after 5 years, type 2 at diagnosis.
Summary table
| Stage | Findings | Treatment |
|---|---|---|
| Mild to moderate NPDR | Microaneurysms, haemorrhages, hard exudates | Control of glucose, blood pressure and lipids; follow-up |
| Severe NPDR | The 4-2-1 rule | Close follow-up; consider PRP in selected cases |
| PDR | NVD or NVE, vitreous haemorrhage | PRP or anti-VEGF |
| Centre-involving DME | Central thickening on OCT, reduced vision | Anti-VEGF; dexamethasone if resistant |
| Advanced PDR | Non-clearing haemorrhage, tractional detachment of the macula | Vitrectomy |
Free exam questions
מבין המטופלים הבאים הסובלים מסוכרת לא מאוזנת שנים רבות למי הסיכון הגבוה ביותר לפתח רטינופתיה סוכרתית? (the question as examined, in Hebrew)
- א. מטופל עם מחלת לב איסכמית
- ב. תת פעילות של בלוטית התריס לא מאוזנת
- ג. עישון מעל 10 .סיגריות ליום
- ד. מטופל עם ממאירות של המעי הגס
מחקר השווה בין 8,276 חולי סוכרת עם דמנציה לעומת 8,276 חולי סוכרת ללא דמנציה התואמים להם מבחינת גיל ומין. במחקר זה נבדקו התרופות אותן נטלו המטופלים לסוכרת, ונבדק הקשר בין נטילת תרופות שונות לסוכרת לבין התפתחות דמנציה. מהו המדד המתאים לתיאור גודל האפקט בסוג המחקר המתואר? (the question as examined, in Hebrew)
- א. Odds Ratio
- ב. Relative Risk
- ג. Confidence interval
- ד. Kaplan-Meier analysis
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Sources
- AAO Preferred Practice Pattern: Diabetic Retinopathy, 2019 — Classification, screening and treatment
- American Diabetes Association: Standards of Care in Diabetes, 2025 — Retinopathy, neuropathy and foot care
- AAO Basic and Clinical Science Course, Section 12: Retina and Vitreous, 2024-2025 — Diabetic retinopathy
Sources are given for further reading; the text is written afresh and not copied from them.
Reviewed by the Examqo AI Professor · 2026-11-06. The text may contain errors; when in doubt, check the source.