Iron levels in human retina: sex difference and increase with age.

Oxidative stress is believed to be important in physiological aging and age-related diseases. Iron is a potent pro-oxidant implicated in several age-related diseases. While serum ferritin, as an estimate of body stores of iron, has been shown to increase with age, few studies have directly addressed the effect of age on human neural tissue iron levels. We used atomic absorption spectrophotometry to assess quantitatively iron levels within the eye structures, retina and retinal pigment epithelium/choroid of normal human eyes of various ages and of both sexes. We found that retinal iron increases with age, similar to serum ferritin levels. Women had more retinal iron than men at all ages, suggesting that there may be gender-specific influences on iron regulation.