Multicenter ophthalmic and nutritional age-related macular degeneration study--part 2: antioxidant intervention and conclusions
Richer, S.
Journal of the American Optometric Association 67(1): 30-49
1996
ISSN/ISBN: 0003-0244 PMID: 8825016 Document Number: 461817
A prospective 18 month, double-blind case-controlled study was designed to determine whether a specific over-the-counter multivitamin/mineral/antioxidant nutrient capsule taken twice daily prevents the progression of, or improves the outcome of non-exudative ARMD. Two randomly assigned experimental ARMD groups are compared to each other, to age matched ARMD-free case controls and to 1994 NHANES III nutritional data. Thirty-two dry ARMD patients assigned to group one (placebo) and 39 dry ARMD patients were assigned to group two (Ocuguard, a broad spectrum antioxidant capsule). A third age and sex matched ARMD-free case control group of 13 patients who met the same entrance criteria were also selected. All participants underwent thorough visual and nutritional evaluation prior to initiation of the study. Both ophthalmic tests and dietetic assessments were also performed at 6, 12 and 18 months following a 2-week initiation period. In comparison to NHANES-III age stratified population data and the Recommended Daily Allowance (but not case controls), the ARMD population manifested decreased intake of nutrients vital to cardiovascular health: vitamin E, magnesium, zinc, vitamin B6 and folic acid. The two randomly assigned experimental groups were well matched, with little difference in baseline demographic, ocular, hematologic and pre-intervention symptoms. There were differences in nutritional intake between the two groups, due primarily to significantly higher percent ideal body weight in group two. The experimental design, subjects, procedures and baseline data for the prospective double blind dry ARMD-antioxidant intervention study have been described in Part 1. At eight DVA medical centers, 32 patients (group one) were assigned a placebo and 39 patients (group two) a "broad spectrum" antioxidant capsule. Data was collected in five areas: demographic; ophthalmic; dietary analysis of daily food intake; serum analysis; and adverse gastrointestinal symptoms. Data was serially acquired at baseline, 6 months, 12 months and 18 months, and was analyzed by univariate repeated factors ANOVA, p = 0.05. Group two (antioxidant po BID) maintained their distance LogMAR visual acuity (p = 0.03), while there was a trend toward both stabilized near M print (p = 0.07) and 6 cycle/degree contrast sensitivity (p approximately 0.10), in left eyes. However, group two (antioxidant) also had increased cortical opacification of the right lens (p = 0.04), compared to group one (placebo). Self perceived stabilization of vision was reported by subjects in group two and supported the objective data (Pearson chi square; p = 0.05). A specific 14 component antioxidant capsule taken twice daily stabilized but did not improve dry ARMD over the study period of 1.5 years. The ARMD stabilized eyes had less advanced disease functionally but not by fundus appearance. Decreased intake of cardioprotective nutrients (vitamin E, zinc, magnesium, B6 and folate) in ARMD patients remained constant over the course of the trial.