Age-Related Macular Degeneration (ARMD)

Snapshot

• A 65-year-old male presents with progressive left-eye central vision loss over the last few months. His peripheral vision is intact. The patient denies smoking and drinks a 2-3 alcoholic beverages during social gatherings. When looking at a specific region in a line grid, he reports a dark “spot” in the center, with bent lines. Dilated ophthalmic examination is shown.

Introduction

• Degenerative disease involving the macula → loss of central vision
  • peripheral and navigational vision is uninvolved
• Classification
  • wet (neovascular, exudative)
    • pathogenesis involves choroidal neovascularization
      • secondary to vascular endothelial growth factor (VEGF)
    • disease progression usually occurs over months
  • dry (atrophic)
    • pathogenesis unclear
    • drusen deposition (early in disease), retinal atrophy, central retinal degeneration
    • disease progression usually occurs over decades
• Epidemiology
  • mostly affects those > 50 years old
• a leading cause of blindness

Presentation

• Symptoms 
  • wet-ARMD
    • acute visual distortion
    • central vision loss
      • secondary to fluid accumulation
    • usually affects one eye
    • metamorphopsia
      • can appear early in disease
  • dry-ARMD
    • gradual vision loss
• metamorphopsia

Evaluation

• Clinical diagnosis 
  • retinal examination
    • wet-ARMD
      • hemorrhage or fluid in subretina
      • neovascularization
        • macular grayish-green discoloration
    • dry-AMD
      • drusen deposition
      • areas of retinal atrophy (depigmentation)
      • retinal pigment epithelium motteling (pigmentation)
• Fluorescein retinal angiography
• Optical coherence tomography (OCT)
• Amsler grid
• line distortion seen on grid

Differential

• Vascular tumors of the retina
• e.g., von Hippel-Lindau disease

Treatment

• wet-ARMD
  • VEGF inhibitors (e.g., bevacizuzmab)
  • photodynamic therapy
  • zinc and antioxidant vitamins
• dry-ARMD
• zinc and antioxidant vitamins

Prognosis, Prevention, and Complications

• Prevention
  • certain vitamin supplements and dietary factors may reduce the risk of ARMD
• Complications
  • blindness