Factors associated with age-related macular degeneration. An analysis of data from the first National Health and Nutrition Examination Survey.

Data from the first National Health and Nutrition Examination Survey collected between 1971 and 1972 were used to determine what factors are associated with the prevalence of age-related macular degeneration. The study was limited to those who were at least 45 years old at the time of the ophthalmology examination. Stratified analysis, adjusting for age, showed that education, systolic blood pressure, past history of hypertension, cerebrovascular disease, and refractive error were all associated with macular degeneration. With the exception of education, these factors remained statistically significant when simultaneously entered into a logistic regression model. The frequency of consumption of fruits and vegetables rich in vitamins A and C suggested a negative association with the prevalence of macular degeneration after stratified adjustment for age. In a logistic regression analysis, adjusting for demographic and medical factors, the inverse association of vitamin C with age-related macular degeneration was no longer present. The frequency of consumption of fruits and vegetables rich in vitamin A remained negatively correlated with age-related macular degeneration even after adjustment for demographic and medical factors.