Age-related Macular Degeneration (AMD)

Introduction

Age-related macular degeneration (AMD) is a neurodegenerative disease that produces irreversible loss of central vision due to the damage to the macula, the center region of the retina.

  • Two distinct types of AMD have been identified: geography atrophy (GA) "dry" and choroidal neovascularization (CNV), exudative "wet".



Risk Factors

The two most important risk factors for AMD are age and smoking.

  • Drusen development and AMD diagnosis can occur at any age, although usually after the age of 50.

Additional risk factors include

  • Ethnicity - Higher prevalence in European compared to Asian, Hispanic and African
  • Genetics
  • Hypertension
  • Obesity
  • Cardiovascular disease



Symptoms

Suspect AMD if older patient presents with typical clinical symptoms including

  • Sudden onset of central visual distortion
  • Metamorphopsia (perceived distortion of objects)

NOTE: The Amsler grid is a simple screening test for macular degeneration.



Treatment

The goal of treatment is to slow progression of AMD and prevent severe visual impairment or blindness.

Smoking Cessation is very important to include as first-line nonpharmacotherapeutic treatment.

For patients with intermediate or advanced AMD, studies support use of antioxidant vitamins and minerals to slow progression to advanced AMD.

  • Daily doses should consists of vitamin C 500 mg, vitamin E 400 IU, lutein 10 mg, zeaxanthin 2 mg, zinc oxide 80 mg and copper 2 mg. Beta-carotene 15 mg may be used in lieu of lutein and zeaxanthin in non-smokers.

In patients with wet AMD, the use of anti-VEGF agents, photodynamic therapy (PDT), and even surgery has been studied in an attempt to slow progression to vision loss.

  • Use intravitreal injection therapy with pan-VEGF inhibiting agents, such as aflibercept, bevacizumab, and ranibizumab.

Studies are conflicting regarding the implementation of a diet high in omega-3 fatty acids such as EPA and DHA found in fish, and plant-based omega 3 fatty acid supplements, such as ALA for prevention of AMD.



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