[Retinal hazard from blue light emitting diode].
OBJECTIVE
To compare the effect of exposure time from a blue(460 nm) light emitting diode(LED) on the morphology of the outer retina and determine conditions where damage occurs.


METHODS
Young adult rhesus monkeys were anesthetized, and received blue LED exposure from a modified slit-lamp. A 3 mm beam of 0.85 mW was imaged onto the retina through a lens positioned before the cornea and exposure damage was determined at time intervals for 12 to 90 min. Fundus photography, fluorescein angiography(FAG), retinal tomography(HRT), and s-cone electororetinogram(S-ERG) were recorded at baseline, 2, and 30 days.


RESULTS
Two days after 40 min exposure, there was a grey, discolored region, which was over-fluorescent in FAG, and an incresse in HRT and S-ERG corresponding to the site which was exposed to LED light. In histological examination at 30 days, the LED had caused produced a marked disruption of the disks of photoreceptor cells, damaged retinal pigment epithelium(RPE) apical villi, and a loss of RPE melanin after 90 min exposure.


CONCLUSIONS
A threshold level was found around 40 min. This morphological damage may impair function and continuous exposure to blue light is potentially dangerous to vision.
Koide
R
R
Department of Ophthalmology, School of Medicine, Showa University, 2-14-19 Nishinakanobu, Shinagawa-ku, Tokyo 142-0054, Japan.
Ueda
T N
TN
Dawson
W W
WW
Hope
G M
GM
Ellis
A
A
Somuelson
D
D
Ueda
T
T
Iwabuchi
S
S
Fukuda
S
S
Matsuishi
M
M
Yasuhara
H
H
Ozawa
T
T
Armstrong
D
D
D000818:Animals; D008027:Light / Q000009:adverse effects*; D008253:Macaca mulatta; D008297:Male; D010857:Pigment Epithelium of Eye / Q000528:radiation effects* / Q000648:ultrastructure; D011833:Radiation Injuries, Experimental / Q000473:pathology; D012160:Retina / Q000473:pathology / Q000528:radiation effects*