ABSTRACT
The cornea is generally considered to be intensely exposed to reactive oxygen
species (ROS), and also to have special problems dealing with these reactive
species.1 There are many reasons to believe this is true:
First, to enable vision, the cornea is by necessity intensely exposed to light,
with a high risk for photochemical reactions. In addition, with the exception of the
epithelium, the corneal tissues have slow turnover rates, which means that com-
pounds damaged by oxidative processes are likely to be present in the corneal
tissue for long periods of time. Furthermore, the cornea has optical demands
requiring a macroscopically and microscopically perfect tissue organization, with
demands by far exceeding those put upon most tissues and organs of the body.
Last, like the lens and the vitreous body, the cornea is avascular, which also
reduces its possibility to ‘‘export’’ compounds damaged by oxidation.
