Phototoxic effects of commercial photographic flash lamp on rat eyes.
BACKGROUND
To determine whether exposure of the cornea and retina of rats to flashes from a commercial photographic flash lamp is phototoxic.


METHODS
Sprague-Dawley rats were exposed to 10, 100, or 1,000 flashes of the OPTICAM 16M photographic flash lamp (Fujikoeki, Japan) placed 0.1, 1, or 3 m from the eyes. Corneal damage was assessed by a fluorescein staining score, and the retinal damage by eletroretinography (ERG) and histology before and 24 h after exposure.


RESULTS
Exposure of the eyes to 1,000 flashes at 0.1 m increased the fluorescein staining score significantly (P = 0.009, the Mann-Whitney test). Scanning electron microscopy (SEM) of the cornea showed a detachment of the epithelial cells from the surface after this exposure. The amplitude of the a-wave was decreased significantly by 23.0% (P = 0.026) of the amplitude before the exposure, and the b-wave by 19.7% (P = 0.0478) following 1,000 flashes at 0.1 m but not by the other exposures. TUNEL-positive cells were present in the outer nuclear layer only after the extreme exposure, but no significant decrease in retinal thickness was seen under any condition. The fluorescein staining score and ERGs recovered to control levels within 1 week.


CONCLUSIONS
Light exposure to a photographic flash lamp does not induce damage to the cornea and retina except when they are exposed to 1,000 flashes at 0.1 m.
Inoue
Makoto
M
Department of Ophthalmology, Keio University School of Medicine, 35 Shinanomachi, Shinjuku, Tokyo, 160-8582, Japan. inoshin@sc.itc.keio.ac.jp
Shinoda
Kei
K
Ohde
Hisao
H
Tezuka
Keiji
K
Hida
Tetsuo
T
D000818:Animals; D003132:Commerce; D004307:Dose-Response Relationship, Radiation; D004596:Electroretinography; D004847:Epithelial Cells / Q000528:radiation effects / Q000648:ultrastructure; D019573:Epithelium, Corneal / Q000503:physiopathology / Q000528:radiation effects / Q000648:ultrastructure; D005123:Eye / Q000528:radiation effects*; D019793:Fluorescein; D005456:Fluorescent Dyes; D020287:In Situ Nick-End Labeling; D008027:Light / Q000009:adverse effects*; D008297:Male; D008855:Microscopy, Electron, Scanning; D010781:Photography; D051381:Rats; D017207:Rats, Sprague-Dawley; D012160:Retina / Q000473:pathology / Q000503:physiopathology / Q000528:radiation effects; D013194:Staining and Labeling
D005456:Fluorescent Dyes; D019793:Fluorescein