Introduction:
Observational as well as in vitro and intervention studies suggest that lutein may play a preventive role in age-related macular degeneration (AMD) (1-5). In the Lutein Antioxidant Supplement Trial or LAST, the effects of lutein on macular pigment optical density (MPOD) and objective visual outcomes were evaluated in patients with established atrophic AMD. First reported at an annual meeting of ARVO, the findings were published in the April, 2004 issue of Optometry
.Methods:
This study enrolled 90 veterans with atrophic AMD in a prospective, placebo-controlled, double-blind trial that involved repeated visual measures over a 12 month period. Volunteers were randomly assigned to receive 10 mg of lutein alone, 10 mg of lutein along with antioxidants* or a placebo. The investigators used a clinical evaluation protocol that was previously validated in a pilot case series. Several tests were used to detect and follow the disease in a serial manner. One, the contrast sensitivity function (CSF) assessment measures the least amount of contrast needed to detect a visual stimulus. CSF assessment enables the detection of changes in visual processing earlier than visual acuity. The investigators also employed the SKILL Card clinical test to assess visual acuity at low levels of light and contrast, and monocular visual acuity was measured by Snellen letter equivalent. Additional tests included the Amsler grid, the Activities of Daily Vision Scale and Glare Recovery, a test of macular function where the dark adaptation of the eye is measured after a flash of light centered on the macula. MPOD was measured by heterochromic flicker photometer.
Results:
Subjects in the lutein, and lutein/antioxidant groups showed a significant increase in average MOPD (repeated measures ANOVA; p<.05) over 12 months, compared to a slight decline in the placebo group. The increased MPOD was seen across all stages of AMD (II-IV). While the placebo group had no significant changes in any of the measured outcomes, both the lutein and the lutein/antioxidant treatments improved some measures of visual function, including glare recovery, quality of vision reflected by CSF and near visual acuity. For the lutein group, near visual acuity increased by about 1 line, while it decreased for the placebo-takers.
Conclusion:
According to the authors, this modest prospective clinical trial agrees with studies suggesting AMD to be, in part, a nutrition responsive disorder. LAST demonstrated improvements in symptoms of clinical concern to patients, and indicates the need for larger and longer-term trials to confirm these salutary findings.