Diabetic retinopathy

Epidemiology & Risk Factors

• Epidemiology: Leading cause of blindness in working-age adults (20–74 yrs).
• Risk Factors: DM duration (strongest predictor), poor glycemic control (↑ HbA1c), HTN, nephropathy, pregnancy.

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Clinical Features

• Non-Proliferative Diabetic Retinopathy (NPDR):
  • Microaneurysms (earliest sign), dot-and-blot hemorrhages, hard exudates, cotton-wool spots.
  • Macular edema: Leading cause of visual impairment in NPDR.
• Proliferative Diabetic Retinopathy (PDR):
  • Driven by retinal ischemia (↑ VEGF).
  • Neovascularization (disc/retina/iris), vitreous hemorrhage (sudden floaters/vision loss), tractional retinal detachment.

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Diagnosis

• Screening (Dilated Fundoscopy):
  • T1DM: 3–5 yrs after dx, then annually.
  • T2DM: At time of dx, then annually.
• Confirmatory / Advanced Imaging:
  • Optical Coherence Tomography (OCT): Gold standard for macular edema.
  • Fluorescein Angiography (FA): Detects non-perfusion and neovascular leakage.

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Differential Diagnostics

• Hypertensive Retinopathy: Diff by AV nicking, copper/silver wiring, flame hemorrhages.
• Central Retinal Vein Occlusion (CRVO): Diff by acute painless vision loss with “blood and thunder” fundus.
• Central Retinal Artery Occlusion (CRAO): Diff by acute profound vision loss with cherry-red spot and retinal pallor.
• Wet AMD: Diff by elderly pt, drusen, localized subretinal neovascularization/hemorrhage.

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Management

• Systemic: Strict glucose control (HbA1c ≤ 7.0%) + BP control (< 130/80 mmHg).
• Diabetic Macular Edema: Intravitreal anti-VEGF (e.g., Aflibercept, Bevacizumab).
• Proliferative DR (PDR): Panretinal photocoagulation (PRP) laser and/or anti-VEGF.
• Vitrectomy (Surgery): Non-clearing vitreous hemorrhage, macula-threatening tractional retinal detachment.

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Complications

• Vitreous hemorrhage.
• Tractional retinal detachment.
• Neovascular glaucoma.
• Irreversible blindness.