A case of retinal injury by a violet light-emitting diode.
OBJECTIVE
To describe the first case of retinal injury by a misuse of a toy using light-emitting diode.


METHODS
A 15-year-old male Japanese student received irradiation on his right eye by a 5 mW light-emitting diode of 410 nm wavelength for 20 seconds in 2 days. He noticed decreased vision and central scotoma approximately 2 weeks later from these events. The mechanism of injury was evaluated from the estimated irradiance on the retina by comparison with experimental threshold data published.


RESULTS
Chorioretinal atrophy with visual loss and central scotoma has remained on the fovea. The patient received an estimated dose of 1.58 J/cm 2 times, which was close to the experimentally determined radiant exposure for photochemical injury of rat retina.


CONCLUSIONS
The violet light from light-emitting diodes is a potential hazard for the retina, and thus, direct viewing into the beam should be avoided. Children, especially, should not be allowed to play with such toys without being carefully instructed about their proper use and fully supervised.
From the *Department of Ophthalmology, Seirei Hamamatsu General Hospital, Hamamatsu, Japan; †Photochemical Medicine Department, Photon Medical Research Center, Hamamatsu University School of Medicine, Hamamatsu, Japan; and ‡Institute of Biomedical Optics, University of Lübeck, Lübeck, Germany.
Akira
A
Obana
Ralf
R
Brinkmann
Yuko
Y
Gohto
Kasumi
K
Nishimura