Abstract
Purpose: :
Studies have demonstrated that lutein and zeaxanthin may play an important protective role in the macula by absorbing blue light and quenching free radicals. Recent advances in Resonance Raman Spectroscopy (RRS) allow for the noninvasive measurement of these carotenoids in the human macula. Since these carotenoids are obtained only from the diet, we propose that patients with nutrient malabsorption may demonstrate lower carotenoid levels in the macula and/or blood. Furthermore, these lower levels may correlate with early–onset drusen. Diseases such as celiac sprue (gluten enteropathy) and Crohn’s disease have known effects on nutrient absorption, and knowledge of AMD risk in this patient population would be valuable in recommending care.
Methods: :
A medical history including family history of gastrointestinal disorders was obtained from subjects with and without malabsorption under age 55. Five RRS readings were collected from each eye. Carotenoids were extracted from 100 µl of serum and analyzed by high performance liquid chromatography (HPLC). Data were analyzed for significance by unpaired, two–tailed Student’s t–tests. Fundus examinations were performed by retinal specialists at the Moran Eye Center.
Results: :
Patients with malabsorption (n=22) showed significantly lower levels of macular carotenoids compared to subjects without (n=25, p<.001). In both groups, levels of macular carotenoids declined with age. Patients with celiac disease had 1.6 times the serum zeaxanthin relative to normal controls (p<.01). The lowest serum levels of both lutein and zeaxanthin measured in any patient occurred in a patient with Crohn’s disease. In this patient, the levels were 8 and 5 times lower than the normal average for lutein and zeaxanthin, respectively. A soft, intermediate–sized druse was observed and photographed in one 48 year old patient with celiac disease.
Conclusions: :
Subjects with malabsorption registered lower levels of macular carotenoids than those without as measured by RRS, and levels appeared to decline with age. Subjects with celiac disease registered significantly higher levels of zeaxanthin, perhaps because consumption of corn is encouraged in a gluten–free diet. Fundus examination demonstrated the presence of early–onset drusen in one subject with celiac disease. Intestinal malabsorption results in lower macular carotenoid levels and may increase risk for early–onset drusen. High–dose carotenoid supplementation may prove valuable in this particular patient population.
Keywords: age-related macular degeneration • carotenoids/carotenoid binding proteins • drusen