In a previous EduFacts (Volume 3, number 7) we summarized results from the prospective Pathologies Oculaires Liées á l'Age (POLA) Study, which demonstrated a high level of antioxidant enzymes in patients with AMD and cataract. The authors suggested that elevated levels of antioxidant levels may be a marker of oxidative stress in AMD patients. These same investigators recently published an evaluation of the relationship between prevalence of AMD and plasma levels of vitamin E, retinol and vitamin C to determine if a lower plasma level of these antioxidants was associated with higher risk of AMD.

Methods:

During 1995 through 1997, participants were recruited in the French city of Séte on the Mediterranean. At the baseline evaluation, presence of AMD was determined by fundus-photograph grading using the Wisconsin system in 2584 patients. Classification was collapsed for analysis into: none, early or late (neovascular) AMD.

Statistical Evaluation:
Subjects were divided into groups based on quintile level of the lipid-standardized plasma vitamin E levels. Adjusted Odd's Ratios were computed ( adjusting for age ,sex education, BMI, diabetes, smoking, and various cardiovascular parameters), using the lowest quintile as the reference group. After multivariate adjustment, lipid-standardized vitamin E was inversely associated with risk of late AMD (exudative/ atrophy). The relative risk of late AMD in the highest quintile level was 0.18 (p=0.004). This suggests a decreased risk of late AMD of over 80%. Lipid standardized plasma vitamin E level was also inversely associated with early signs of AMD ( any kind of soft drusen, hyperpigmentation). The Odd's Ratio was 0.72 (28% decreased risk) in the highest vs lowest quintile level.

The authors stated that these results suggest that vitamin E may provide protection against AMD but that randomized interventional studies were necessary to establish such an effect..

References

1. Delcourt, C, Cristol JP, Tessier F et al. Age Related Macular Degeneration and Antioxidant Status in the POLA Study. Arch Ophthalmol 1999;117:1384-1390.