Skip to main content
PMC home page
Canadian Family Physician logoLink to Canadian Family Physician
. 2013 May;59(5):503.

Vitamins for age-related macular degeneration demonstrate minimal differences

Michael R Kolber 1, Mathew Tennant 2, Tony Nickonchuk 3
PMCID: PMC3653653  PMID: 23673586

Clinical question

Does taking ocular vitamins (including antioxidants and zinc) decrease the progression of age-related macular degeneration (AMD)?

Bottom line

Ocular vitamins only slow visual loss in AMD patients with intermediate and severe retinal findings (number needed to treat [NNT] = 13). Progression to advanced AMD is rare in patients with minimal AMD, and ocular vitamins do not prevent AMD in those without AMD. Components of ocular vitamins are potentially harmful and should be used only in selected patients.

Evidence

The largest multicentre, double-blind, placebo-controlled RCT of 4757 patients with AMD1 examined the effects of antioxidants (500 mg of vitamin C, 400 IU of vitamin E, and 15 mg of beta-carotene); zinc (80 mg of zinc oxide); and antioxidants in combination with zinc on AMD progression.

  • Mean age 69 years; 56% females; 6.3 years follow-up.

  • Baseline retinal photography classified patients in categories 1 (minimal) to 4 (advanced).

Outcomes:

  • For 15-letter visual acuity loss:
    • -Pooled together, category 2, 3, and 4 patients had no significant improvement with any intervention.
    • -Category 3 and 4 patients had statistically significantly reduced visual loss for antioxidants with zinc (23%) versus placebo (29%); NNT = 17 (P = .008).
  • For progression to advanced AMD (predominantly neovascularization):
    • -Category 3 and 4 patients had statistically significantly reduced progression with zinc (NNT = 17, P = .008) and antioxidants with zinc (NNT = 13, P = .001).

Limitations:

  • Category 1 patients (23% of sample) were excluded, reporting was selective, adjustments were made for baseline characteristics, and the trial was industry supported.

  • Inconsistent results seen in shorter, smaller studies.2

Context

  • In developed countries AMD is a common cause of visual loss.3 Neovascular AMD accounts for more than 80% of AMD visual loss, but less than 15% develop neovascular AMD (< 1% of category 1 or 2 patients).1,4

  • Risk factors for AMD include being white, advanced age, smoking, obesity, and family history.4–6

  • For patients without AMD, vitamin E or beta-carotene alone do not prevent AMD,7 and Canadian retina specialists recommend taking ocular vitamins.8

  • Antioxidants increase adverse events including overall mortality (relative risk of 1.04, 95% CI 1.01 to 1.07).9

Implementation

Visual impairment affects 23% of US patients older than 80 years,3 most commonly from cataracts, AMD, and glaucoma.3 Ocular vitamins for AMD cost about $20 per month and do not prevent or slow the progression of cataracts.10 Intravitreal injections of vascular endothelial growth factor inhibitors ranibizumab or bevacizumab decrease the risk of further visual loss and might improve visual acuity in AMD patients who progress to neovascularization.11 Bevacizumab (off-label use) has been shown to be clinically noninferior to ranibizumab and is substantially cheaper.

Tools for Practice articles in Canadian Family Physician (CFP) are adapted from articles published on the Alberta College of Family Physicians (ACFP) website, summarizing medical evidence with a focus on topical issues and practice-modifying information. The ACFP summaries and the series in CFP are coordinated by Dr G. Michael Allan, and the summaries are co-authored by at least 1 practising family physician and are peer reviewed. Feedback is welcome and can be sent to toolsforpractice@cfpc.ca. Archived articles are available on the ACFP website: www.acfp.ca.

Footnotes

The opinions expressed in Tools for Practice articles are those of the authors and do not necessarily mirror the perspective and policy of the Alberta College of Family Physicians.

References

  • 1.Age-Related Eye Disease Study Research Group A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss. Arch Ophthalmol. 2001;119(10):1417–36. doi: 10.1001/archopht.119.10.1417. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 2.Evans JR. Antioxidant vitamin and mineral supplements for slowing the progression of age-related macular degeneration. Cochrane Database Syst Rev. 2006;(2):CD000254. doi: 10.1002/14651858.CD000254.pub2. [DOI] [PubMed] [Google Scholar]
  • 3.The Eye Diseases Prevalence Research Group Causes and prevalence of visual impairment among adults in the United States. Arch Ophthalmol. 2004;122(4):477–85. doi: 10.1001/archopht.122.4.477. [DOI] [PubMed] [Google Scholar]
  • 4.Jager RD, Mieler WF, Miller JW. Age-related macular degeneration. N Engl J Med. 2008;358(24):2606–17. doi: 10.1056/NEJMra0801537. [DOI] [PubMed] [Google Scholar]
  • 5.Clemons TE, Milton RC, Klein R, Seddon JM, Ferris FL, 3rd, Age-Related Eye Disease Study Research Group Risk factors for the incidence of advanced age-related macular degeneration in the Age-Related Eye Disease Study. Ophthalmology. 2005;112(4):533–9. doi: 10.1016/j.ophtha.2004.10.047. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 6.Ting AY, Lee TK, MacDonald IM. Genetics of age-related macular degeneration. Curr Opin Ophthalmol. 2009;20(5):369–76. doi: 10.1097/ICU.0b013e32832f8016. [DOI] [PubMed] [Google Scholar]
  • 7.Evans JR, Lawrenson JG. Antioxidant vitamin and mineral supplements for preventing age-related macular degeneration. Cochrane Database Syst Rev. 2012;(6):CD000253. doi: 10.1002/14651858.CD000253.pub3. [DOI] [PubMed] [Google Scholar]
  • 8.Cruess AF, Berger A, Colleaux K, Greve M, Harvey P, Kertes PJ, et al. Canadian expert consensus: optimal treatment of neovascular age-related macular degeneration. Can J Ophthalmol. 2012;47(3):227–35. doi: 10.1016/j.jcjo.2012.03.007. [DOI] [PubMed] [Google Scholar]
  • 9.Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database Syst Rev. 2012;(3):CD007176. doi: 10.1002/14651858.CD007176.pub2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 10.Mathew MC, Ervin AM, Tao J, Davis RM. Antioxidant vitamin supplementation for preventing and slowing the progression of age-related cataract. Cochrane Database Syst Rev. 2012;(6):CD004567. doi: 10.1002/14651858.CD004567.pub2. [DOI] [PMC free article] [PubMed] [Google Scholar]
  • 11.Comparison of Age-related Macular Degeneration Treatments Trials (CATT) Research Group Ranibizumab and bevacizumab for treatment of neovascular age-related macular degeneration: two-year results. Ophthalmology. 2012;119(7):1388–98. doi: 10.1016/j.ophtha.2012.03.053. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from Canadian Family Physician are provided here courtesy of College of Family Physicians of Canada

RESOURCES