Epidemiology

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Etiology

Retinal artery occlusion

• Embolism
  • Release of thrombotic emboli as a result of carotid artery atherosclerosis (most common)

Retinal vein occlusion

• Systemic diseases
  • Atherosclerosis
  • Hypertension
  • Diabetes mellitus

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Pathophysiology

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Clinical features

Retinal artery occlusion

• Central retinal artery occlusion (CRAO)
  • Sudden, painless loss of vision in one eye (often described as a “descending curtain”)
  • Ophthalmoscopic findings
    • Grayish-white (cloudy) discoloration of the entire retina
      • A result of edema within the nerve fiber layer (NFL)
    • Cherry-red spot at the fovea centralis
      • No nerve fibers are present in the foveal avascular zone (FAZ). Therefore, the FAZ is not affected by edema of the nerve fiber layer. The underlying choroid is clearly visible as a cherry-red spot against a dull white background.
• BRAO
  • Sudden onset of visual field defects (scotomas) in the affected eye
  • Ophthalmoscopic findings
    • Grayish-white discoloration of the retinal quadrant supplied by the affected vessel

Retinal vein occlusion

• Ischemic CRVO
  • Sudden, severe loss of vision in the affected eye
  • Ophthalmoscopic findings
    • Many dot-and-blot and/or flame-shaped hemorrhages in all four retinal quadrants and venous thickening (blood and thunder appearance)
    • Cotton wool spots
      • Characterized by yellow-white deposits on the retina
      • Caused by swelling of retinal nerve fibers due to ischemia
    • Severe macular edema
    • Severe papilledema

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Diagnostics

Retinal artery occlusion

• Evaluation for cardiovascular risk factors:
  • Carotid doppler (to look for atherosclerotic plaques)
  • Echocardiography (to identify potential sources of emboli, e.g. cardiac vegetations, patent foramen ovale)
• Tests to rule out temporal arteritis:
  • Inflammatory markers (e.g., ↑ ESR)
  • Temporal artery biopsy

Tip

Retinal artery occlusion is also called ‘retinal stroke”; patients with retinal artery occlusion are at a significantly higher risk of having a stroke.

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Treatment

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