Lutein, the antioxidant found in dark green leafy vegetables and many fruits, has been believed to protect eyes from UV and oxidative damages. The study published in the journal Ophthalmology in October 2002 corroborates this assertion.

The scientists at University of Utah (Department of Ophthalmology and Visual Sciences, Moran Eye Center, University of Utah School of Medicine, Salt Lake City, Utah, and Department of Physics and the Dixon Laser Institute, University of Utah, Salt Lake City, Utah) published an article under the title "Resonance Raman measurement of macular carotenoids in normal subjects and in age-related macular degeneration patients." in the journal as a report of their study on the correlation between the amount of lutein and zeaxanthin in macula and age-related macular degeneration (AMD).

Background
Dietary carotenoids lutein and zeaxanthin are thought to play a protective role against visual loss from age-related macular degeneration (AMD) through antioxidant and light screening mechanisms. This can be tested using a novel noninvasive objective method to quantify lutein and zeaxanthin in the human macula using resonance Raman spectroscopy and by comparing macular pigment levels in AMD and normal subjects.

Methods
For this observational study of an ophthalmology clinic-based population, 93 AMD eyes from 63 patients and 220 normal eyes from 138 subjects have been employed. Macular carotenoid levels were quantified by illuminating the macula with a low-power argon laser spot and measuring Raman back-scattered light using a spectrograph. This technique is sensitive, specific, and reproducible even in subjects with significant macular pathologic features.
Raman signal intensity at 1525 cm(-1) generated by the carbon-carbon double-bond vibrations of lutein and zeaxanthin.

Results
Carotenoid Raman signal intensity declined with age in normal eyes (P < 0.001). Average levels of lutein and zeaxanthin were 32% lower in AMD eyes versus normal elderly control eyes as long as the subjects were not consuming high-dose lutein supplements (P = 0.001). Patients who had begun to consume supplements containing high doses of lutein (>/=4 mg/day) regularly after their initial diagnosis of AMD had average macular pigment levels that were in the normal range (P = 0.829) and that were significantly higher than in AMD patients not consuming these supplements (P = 0.038).

Conclusion
These findings are consistent with the hypothesis that low levels of lutein and zeaxanthin in the human macula may represent a pathogenic risk factor for the development of AMD. Resonance Raman measurement of macular carotenoid pigments could play an important role in facilitating large-scale prospective clinical studies of lutein and zeaxanthin protection against AMD, and this technology may someday prove useful in the early detection of individuals at risk for visual loss from AMD.