Retinal cell death by light damage.
OBJECTIVE
To determine the relationship between apoptotic photoreceptor cell death and the duration of light exposure.


METHODS
Ten-week-old male albino rats (Wistar strain) were dark-adapted for 2 days and then exposed to intense light for 12 hours, and 1, 2, 3, 7, 14, 21, and 28 days. The presence of apoptosis was confirmed by electron microscopy and the terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) method. Differences in the apoptotic processes of the photoreceptor cells in the superior, posterior pole, and inferior portions of the retina were determined.


RESULTS
Photoreceptor cells showed TUNEL-positive staining, whereas the cells in the inner nuclear layer, ganglion cell layer and retinal pigment epithelia exhibited weak positive or negative TUNEL staining. By electron microscopy, photoreceptor cells showed typical apoptotic nuclear changes and formation of apoptotic bodies.


CONCLUSIONS
The sensitivity to light damage and style of death differed among retinal cells by location and cell type.
Aonuma
H
H
Department of Ophthalmology, Hamamatsu University School of Medicine, Shizuoka, Japan.
Yamazaki
R
R
Watanabe
I
I
D000818:Animals; D017209:Apoptosis / Q000528:radiation effects*; D002452:Cell Count; D003623:Dark Adaptation; D020287:In Situ Nick-End Labeling; D008027:Light / Q000009:adverse effects*; D008297:Male; D011833:Radiation Injuries, Experimental / Q000209:etiology* / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D012160:Retina / Q000528:radiation effects* / Q000648:ultrastructure; D013997:Time Factors