To print: Select File and then Print from your browser's menu

Title: Ocular Disorders Associated with Increased Risk of Mortality, But Zinc Therapy Appears to Reduce Mortality

URL:

Arch Ophthalmol 2004;122:716-726
05/12/2004 02:56:00 PM
By Joene Hendry

Individuals with advanced age-related macular degeneration (AMD) and with nuclear lens opacities or a history of cataract surgery show increased rates of all-cause mortality, but mortality appears to be reduced with zinc therapy, according to a report from the Age-Related Eye Disease Study (AREDS) Research Group. Study investigators assessed mortality as associated with ocular disorders and treatment characteristics in 4753 patients with AMD, who were a median age of 69 years at baseline. AMD severity was classified as category 1 with few if any small drusen; category 2 with extensive small drusen or nonextensive intermediate-sized drusen; category 3 with extensive intermediate-sized drusen, at least 1 large druse, or noncentral geographic atrophy; or category 4 with unilateral advanced AMD or unilateral vision loss to worse than 20/32 attributable to AMD. Overall, 10.4% of the patients were randomised to daily oral supplements of 80 mg zinc oxide with 2 mg cupric oxide alone, while 10.9% received zinc plus antioxidants including 500 mg vitamin C, 400 IU vitamin E, and 15 mg beta carotene, 14.8% received antioxidants alone, and 13.0% received placebo. During a median of 6.5 years, 11% of the study participants died. All-cause mortality rates were 6.2%, 7.3%, 9.3%, and 14.7% for AMD categories 1, 2, 3, and 4, respectively. Patients with category 4 AMD had an age and sex adjusted relative risk of all-cause mortality of 1.80 compared with those with category 1 AMD. The relative risk of mortality was 1.41 for category 4 AMD compared with category 1 AMD after additional adjustment for race, education, smoking status, body mass index, diabetes mellitus, angina, cancer, and hypertension. A similarly adjusted analysis showed that visual acuity worse than 20/40 in 1 eye had a relative risk of mortality of 1.36 compared with individuals with good acuity in both eyes. Also, nuclear opacity equal to or greater than 4 in at least 1 eye, compared with less than grade 4, had a relative risk of mortality of 1.40, while cataract surgery, compared with none, had a relative risk of 1.55. Additionally, patients randomly assigned to either zinc or zinc plus antioxidants had a relative risk of 0.73 compared with patients who did not receive zinc. "The positive association of zinc with decreased all-cause mortality did not seem to be due to reduction in deaths involving cardiovascular/circulatory disease or cancer," the authors note. While the ocular findings from this study are consistent with findings of other studies that show a potential link between ocular disorders and survival, reports the Writing Team for the AREDS Research Group, "This is the first large randomized trial to report a potential benefit of the use of high doses of zinc on survival."

Copyright © 2009 P\S\L Consulting Group Inc. All rights reserved. Republication or redistribution of P\S\L content is expressly prohibited without the prior written consent of P\S\L. P\S\L shall not be liable for any errors, omissions or delays in this content or any other content on its sites, newsletters or other publications, nor for any decisions or actions taken in reliance on such content.