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Age-Related Macular Degeneration
Aka: Age-Related Macular Degeneration, Macular Degeneration, ARMD
- Epidemiology
- Leading cause of central Vision Loss over age 65 years
- Age-related changes
- Onset after age 50 years (mean onset: 75 years old)
- Prevalence
- Sixth decade: 1%
- Ninth decade: 15%
- Risk Factors
- Advancing age (see epidemiology above)
- Female sex
- White race
- Tobacco Abuse (increases risk 3 fold)
- Diet low in caretenoids
- Increased sunlight exposure
- Cardiovascular disease
- Aspirin (weak evidence only by observation study)
- Neovascular Macular Degeneration (wet AMD) was observed more with Aspirin use for >10 years
- Klein (2012) JAMA 308(23):2469-78 [PubMed]
- Pathophysiology
- Idiopathic
- Retinal photoreceptor dysfunction
- Results from atrophy or Choroidal neovascularization
- Mediators
- Subretinal Hemorrhage
- Subretinal Fibrosis (disciform scarring)
- Subretinal Fluid and lipid accumulation
- Outcome: Decreased Visual Acuity to blindness
- Types
- Non-neovascular, dry, non-exudative ARMD
- Accounts for 80% of all diagnosed cases
- Geographic atrophy and drusen (yellow lipid deposits) predominate
- Neovascular, wet, exudative ARMD
- Accounts for 80% of significant visual Disability
- Choroidal neovascularization (CNV)
- Complicated by Macular Hemorrhage
- Symptoms
- Slow, insidious central Vision Loss
- Decreased dark adaptation
- Exam
- Amsler Grid
- Identifies central visual defects
- While staring at a central black dot, patients report missing or distorted grid lines
- Signs: Bilateral eye involvement
- Drusen
- Yellow lipid deposits, debris within Retinal pigment basement membrane
- Appear with ophthalmoscope as yellow spots on Retina
- Small drusen <63 microns are seen on aging Macula
- Numerous, large drusen are consistent with ARMD
- Geographic atrophy
- Serous Retinal pigment epithelial detachment
- Choroidal neovascularization
- Management: General
- See Prevention and Nutritional Supplements and Antioxidants as below
- Vascular Endothelial Growth Factor Inhibitors
- Indicated for neovascular ARMD
- Intravitreal injection monthly for 4 months (or until stable), then every 3 months
- Monoclonal antibodies available for intravitreal injection
- Bevacizumab (Avastin)
- Not FDA approved, but $150/dose compared to >$1500 for other agents
- Ranibizumab (Lucentis)
- Pagaptanib (Macugen)
- Aflibercept (Eylea)
- Management: Slow progression of CNV-related Vision Loss
- Laser photocoagulation of subretinal blood vessels
- Photodynamic therapy
- Give IV photosensitive drug (wavelength specific)
- Expose eye to targeted wavelength to activate drug
- Experimental
- External beam Radiotherapy
- Vitreoretinal microsurgery
- Management: Visual aids
- Magnifiers
- Increased light sources in home environment
- Prevention: General measures
- Tobacco Cessation is key
- Control Hypertension
- Decrease UV Light exposure (Sunglasses)
- Nutrition
- See Nutritional Supplements below
- Decrease Dietary Fat intake
- Increase grean leafy vegetable intake
- Prevention: Nutritional Supplements and Antioxidants
- Vitamin C, Vitamin E, Beta Carotene, and Zinc
- Indications
- Intermediate or advanced ARMD
- Efficacy
- May reduce progression from intermediate to advanced ARMD (NNT 22 over 5 years)
- May protect the other eye when ARMD is present in one eye
- Does not prevent development of ARMD
- Components (based on AREDS Study)
- Vitamin C 500 mg
- Vitamin E 400 IU
- Zinc 80 mg (25 mg in AREDS2)
- Copper 2 mg
- Beta Carotene 15 mg (removed in new formulations and replaced by Lutein and Zeaxanthin)
- No benefit per AREDS 2 study (and increased Lung Cancer risk in smokers)
- Components (based on AREDS2 Study)
- Includes components of the original AREDS Study without Beta Carotene
- Lutein 10 mg daily
- Improves Vision in men with Macular Degeneration
- Richer (2004) Optometry 75:216-30 [PubMed]
- Zeaxanthin 2 mg
- Zinc 25 mg (reduced from 80 mg in AREDS formulation)
- References
- (2013) Presc Lett 20(8):45
- (2001) Arch Ophthalmol 119:1417-36 [PubMed]
- Components not found useful in ARMD prevention
- Beta Carotene (and Lung Cancer risk in smokers)
- Omega-3 Fatty Acids
- Screening
- Initiate at age 45 years with dilated exam
- References
- Martidis in Yanoff (2004) Ophthalmology p. 925-33
- (2013) Presc Lett 20(3): 16
- Pelletier (2016) Am Fam Physician 94(3):219-26 [PubMed]
- Lim (2012) Lancet 379(9827): 1728-38 [PubMed]
- Weir (2004) CMAJ 170:463-4 [PubMed]