Abstract
Abstract: :
Purpose:It has been hypothesized that the macular carotenoid pigments lutein and zeaxanthin may protect against macular and retinal degenerations and dystrophies. To test this hypothesis, we have measured lutein and zeaxanthin levels noninvasively in patients with retinitis pigmentosa (RP), choroideremia (CHM) and Stargardt’s dystrophy (STGD) and compared them with an age-matched control population. Methods:Using Raman spectroscopy, a novel noninvasive laser-optical technique, we measured macular carotenoid levels in 22 patients (38 eyes) with RP, CHM and STGD and compared them with 80 age-matched normal subjects (134 eyes) without macular pathology. Results:Macular carotenoid levels decreased with age in normals, 20 to 60 years old (P < 0.001). As a group, RP and CHM patients had the same macular carotenoid levels as age-matched normal subjects (P = 0.58 by two-way ANOVA). Only a few (2) STGD patients had acuity good enough to perform the test reliably, and they had much lower levels of macular pigments. Conclusion:Ocular resonance Raman spectroscopic measurement of macular carotenoid levels is sensitive and specific and repeatable at light levels well within established eye safety standards even in patients with substantial visual loss from retinal and choroidal dystrophies. As a group, the patients with RP and CHM had normal levels of macular carotenoids, suggesting that nutritional supplementation with macular carotenoids such as lutein is unlikely to affect the clinical course of RP and CHM.
Keywords: 337 carotenoids/carotenoid binding proteins • 554 retina • 460 macula/fovea