The ability of light to enact damage on the neurosensory retina and underlying structures has been well understood for hundreds of years. While the eye has adapted several mechanisms to protect itself from such damage, certain exposures to light can still result in temporal or permanent damage. Both clinical observations and laboratory studies have enabled us to understand the various ways by which the eye can protect itself from such damage. Light or electromagnetic radiation can result in damage through photothermal, photomechanical, and photochemical mechanisms.
Our understanding of the mechanism of light damage has grown extensively in recent years, but much remains to be learned in the effort to reduce the effects of potentially toxic exposures. This knowledge is pertinent to reducing the morbidity of disease processes potentially related to light exposure, such as age-related macular degeneration. Additionally, as vitreoretinal surgeons continue to introduce the use of potentially photoactive vital dyes such as indocyanine green to enhance surgical techniques, it becomes increasingly important to be able to identify and minimize the potential harmful effects of these agents.
Already, advances in nutritional supplementation, intraocular lens composition and design, and the potential for reduced irradiance from surgical lighting equipment have helped us to reduce the potential for light-induced damage. The availability of new imaging technology, better surgical instrumentation, and new tools for genomic research should help us better understand the mechanism of light-induced injury, as well as identify methods of intervention for minimizing damage to the retina. This review seeks to describe these various processes of injury and many of the variables, which can mitigate these modes of injury.
Youssef PN, Sheibani N, and Albert DM. Retinal light toxicity. Eye, 2011, 25, 1–14.