Introduction:
Epidemiological observations (1,2), as well as in vitro and interventional studies (3-5) suggest that lutein may play a role in AMD. A recent study, the Lutein Antioxidant Supplement Trial or LAST, evaluated the effects of lutein and lutein combined with antioxidants on atrophic AMD. Results from the trial were reported at the meeting of the Association for Research in Vision and Ophthalmology (ARVO) in May, 2002 .
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 received 10 mg of lutein alone, 10 mg of lutein along with antioxidants*, or a placebo.
The LAST study 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.
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. Macular pigment optical density using a heterochromic flicker photometer and lens opacification rating was also assessed.
Results:
Subjects who were given lutein, and lutein plus antioxidants showed a 50% increase in average macular pigment optical density (repeated factors ANOVA; p<0.05) over 12 months, compared to the placebo group. Both the lutein and the lutein/antioxidant treatments significantly improved some measures of visual function, including glare recovery, contrast sensitivity, and visual acuity.
Conclusion:
According to the authors, this modest prospective clinical trial agrees with studies suggesting AMD to be, in part, a nutrition responsive disorder. Larger and longer-term trials must be conducted to confirm these findings.