Diabetic Retinopathy Management

Diabetic Retinopathy (DR)

History

• Initial diagnosis of diabetes mellitus and treatment
  • Poorly controlled diabetes: target HbA1c approx. 7%
• Arterial hypertension: rigorous blood pressure control recommended
• Renal insufficiency: ask about renal function values
• Dyslipidemia
• Pregnancy

Differential diagnosis

Central retinal vein occlusion, branch retinal vein occlusion, ocular ischemic syndrome, hypertensive retinopathy, radiation retinopathy

Classification (ETDRS), management

• No diabetic retinopathy in a patient with known diabetes mellitus
  • ONO: Annual follow-up with OCT M P and photographs
  • ONO: Gestational diabetes: Follow-up in each trimester with OCT M P and photographs

Non-proliferative diabetic retinopathy

• Mild non-proliferative diabetic retinopathy (NPDR):
  • Microaneurysms
• Moderate NPDR, additionally:
  • Retinal hemorrhages (20 per quadrant in 1–3 quadrants)
  • Mild intraretinal microvascular abnormalities (IRMA)
  • Venous beading in > 1 quadrant
  • Cotton-wool spots
  • >  Follow-up in 6 months (26% > PDR, 8% PDR within 12 months)
• Severe NPDR: presence of one of the following features (= 4-2-1 rule), additionally:
  • Extensive hemorrhages and microaneurysms in 4 quadrants
  • Definite venous beading in at least 2 quadrants
  • Moderate IRMA in at least 1 quadrant
  • > Follow-up in 4 months (50% > PDR, 15% > PDR within 12 months)
  • > Fluorescein angiography (FA), if needed scattered panretinal laser photocoagulation
• Very severe NPDR
  • 2 criteria of severe NPDR
  • > Follow-up in 2–3 months (45% > PDR within 6 months)

Proliferative diabetic retinopathy (PDR):

• Mild to moderate PDR
  • Neovascularization (of the disc / NVD = Optic Disc
  • > Follow-up in 2 months
  • > Scattered panretinal laser photocoagulation
• High-risk group
  • NVD (>1/3 disc area)
  • NVD (any) + preretinal or vitreous hemorrhage
  • NVE (> 1 disc diameter (DD)) + preretinal or vitreous hemorrhage
• With clinically significant macular edema (ETDRS):
  • Edema or hard exudates within 500 μm of the fovea
  • Retinal thickening > 1 DD within 1 DD of the fovea
  • Decreased visual acuity due to edema
  • > IVT with anti-VEGF following a treat-and-extend regimen

Intravitreal therapy

Low responder: insufficient response to anti-VEGF after 6–12 months

• Switch to Ozurdex
• Absolute contraindication (CI):
  • Known steroid response
• Relative CI: 
  • Iridotomy (possible migration of the Ozurdex implant into the anterior chamber > endothelial cell loss > counsel the patient accordingly and sensitize them to symptoms
  • Phakic patient (> cataract)

In case of vitreous hemorrhage: evaluate pars plana vitrectomy (PPV)

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Sources: Will's Eye Manual, Eyewiki.org, Blaubuch Inselspital