References on Light Therapy and Eye Damage

Retinopathy and Bright Light Therapy American Journal of Psychiatry 1991; 148(9):1267-1268
W. Vanselow, L. Dennerstein, S. Armstrong, and P. Lockie

"We report bilateral photic maculopathy developing in a patient who had been treated for 5 days with light therapy."
"We strongly recommend that ophthalmological investigation be mandatory in all forms of light therapy, even when there is no history of eye complaint, for the following reasons. 1) Artificial light of the brightness used in light therapy (of the order of 2000 lux) could exacerbate any existing retinopathy, and 2) eye damage discovered subsequent to light therapy could be wrongly attributed to the treatment"

Bright Light Therapy in Focus: Lamp Emission Spectra and Ocular Safety. Technology and Health Care 1996;4(4):403-13.
C.E. Reme, P. Rol, K. Grothmann, H. Kaase, M. Terman.

"In recent years, bright light treatment of seasonal affective disorder (SAD), recurrent depressions in fall and winter, has been discovered. Newer applications include circadian sleep phase disorder, shift work and jet lag ... safety measures for bright light therapy are proposed. They include recommendations for lamps devoid of damaging spectral emissions and standardized therapy fixtures, ophthalmological monitoring of patients with eye diseases and control by optometrists for patients with healthy eyes who are likely to undergo light treatment for extended periods." Abstract

Yearly Review: Ocular Damage. Photochemistry and Photobiology 1993;57(6): 1060-1068
S. Zigman

"As exposure to intense light for phototherapy and severe depression treatment is presently common, a potential danger for phototoxicity is great." Full study

Does Light Therapy Present an Ocular Hazard. American Journal of Psychiatry 1992; 149(12): 1762-3
C.E. Reme and M. Terman

"There should be no lingering doubt that a basic ocular screening is an essential safety precaution"
"Ophthalmological screening- which is quite routine - seems to us to be mandatory. This should be followed by ophthalmological surveillance of light-treated patients with retinal pathology."
"Is there a relation between bright light exposure and retinal pathology? Long term light exposure may be a factor contributing to normal aging, age related degenerative diseases and certain inflammatory responses."

Lack of p75 Receptor does not Protect Photoreceptors from Light-Induced Cell Death. Exp Eye Res 2003 Jan;76(1):125-9
Rohrer B, Matthes MT, LaVail MM, Reichardt LF.

"Light as an environmental factor has been shown to be toxic to rod photoreceptors if the retina is exposed to either high light intensities or to continuous light over a long period of time. The underlying reason for photoreceptor apoptosis is thought to be the oxidative stress induced by excessive light."
"Taken together, these results support the idea that light-induced cell death is mediated by a number of different pathways, some of which are mediated directly by the photoreceptors and start with the absorption of photons" Full Article

Refraction, Spectacles, Contact Lenses, and Visual Rehabilitation American Academy of Ophthalmologists LEO Clinical Topic Update; April 2003
S.M. Stenson, C.E. West.

"The etiology of age-related macular degeneration (ARMD) is multifactorial, but visible light may play a role in the pathogenesis of this potentially devastating disease. In the Maryland watermen study, advanced ARMD was more common in men exposed to increased levels of blue light (400-500 nm), but not in those with increased levels of ultraviolet exposure. Similarly, the Beaver Dam Eye Study found that exposure to visible light was associated with ARMD in men. No association between sunlight and ARMD was found in women in that study, but the authors proposed that the women studied may have had less sunlight exposure...Visible light has also been responsible for acute photic retinopathy caused by the operating room microscope."

Lutein and Zeaxanthin Dietary Supplements Raise Macular Pigment Density and Serum Concentrations of these Carotenoids in Humans. Journal of Nutrition 2003. Apr;133(4):992-8
Bone RA, Landrum JT, Guerra LH, Ruiz CA

"Age-related macular degeneration (AMD) is thought to be the result of a lifetime of oxidative insult that results in photoreceptor death within the macula. Increased risk of AMD may result from low levels of lutein and zeaxanthin (macular pigment) in the diet, serum or retina, and excessive exposure to blue light." Full paper

Screening for Ocular Phototoxicity. Int J Toxicol 2002 Nov-Dec;21(6):491-500
Roberts JE.

".. with very intense light exposure, or with ambient light exposure to the aged eye and/or young or adult eye in the presence of light-activated (photosensitizing) drugs or dietary supplements, cosmetics, or diagnostic dyes, light can be hazardous, leading to blinding disorders. Light damage to the human eye is avoided because the eye is protected by a very efficient antioxidant system and the chromophores present absorb light and dissipate its energy. After middle age, there is a decrease in the production of antioxidants and antioxidant enzymes and an accumulation of endogenous chromophores that are phototoxic." Full Paper

Note: more recent references on the risk of eye damage from light therapy can be found in the section marked - For Therapists