Photochemical retinal damage and it's prevention

我们研究了1.2*10^4 mW/m^2的荧光灯照射后大鼠的光化学损伤。经过12小时的暴露和14天的黑暗恢复后，我们发现ERG a和b波振幅明显下降，视网膜上部外层不清晰层厚度减少。大鼠杆状细胞死亡高峰出现在光照后2-3天，锥状细胞死亡高峰出现在光照后2-3周。光化学视网膜损伤早期，视网膜内层可见大量细胞凋亡，而内核层和神经节细胞层细胞死亡为坏死。全身给予超过0.5 mg/g体重的抗坏血酸和1ug/ul的米克定（肝素结合细胞生长因子）和碱性成纤维细胞生长因子（bFGF），对光化学视网膜损伤有显著的预防作用。-生育酚在电生理实验中没有显示出任何预防作用。a-生育酚缺乏组和a-生育酚补充组大鼠的ERG波幅和外核层厚度下降幅度相同，视网膜a-生育酚含量相差80倍。电镜观察发现，短时间光照下，缺光大鼠视觉细胞外节盘的紊乱程度明显高于补光大鼠，而长时间光照下两组间无明显差异。光照24h后，补足组视细胞核固缩率为60%，缺足组视细胞核固缩率为90%。这种对细胞核的轻视被认为是细胞凋亡。在4.0*10^4 mW/m^2蓝光照射30分钟以上后，大鼠脑电图a波、b波和振荡电位的幅度明显下降。在光照后14天，它们表现出黑暗恢复。家兔在7000勒克斯光照7天后，光适应30分钟的眼电信号振幅下降22%。少

We investigated the photochemical damage in the rat after the exposure to the light of fluorescenht tube (1.2*10^4 mW/m^2). Over 12 hours exposure and after 14 days dark recovery we found a significant decrease in ERG a- and b-waves amplitudes and a decrease of outer unclear layr thickness at upper part of the retina.In the rat, peak of the rod cell death appeared 2-3 days after the light exposure and in the cone it appeared 2-3 weeks later. At the early stage of the photochemical retinal damage, numerous apoptosis were observed in the inner layr of the retina, but cell deaths in inner nuclear layr and ganglion cell layr was necrosis.Systemic administration of over 0.5 mg/g body weight of ascorbic acid and intravitreous injection of 1ug/ul of Mikdine (heparin binding cell growth factor) and basic fibroblast growth factor (bFGF) showed significant preventative effects against the photochemical retinal damage.alpha-tocopherol did not show any preventative effect in electrophysiological s … More tudies. Both a-tocopherol deficient and supplemented rats showed the same decrease in the amplitudes of ERG and in the outer nuclear layr thickness, even the content of a-tocopherol in the retina differed 80 times between two groups. Electron microscopic study revealed more derangement of the visual cell outer segment disks in the deficiency rats than in supplemented rats under the short term light exposure, but prolonged light exposure did not show any difference between these two groups. After 24 hours light exposure, pyknois of the visual cell nucleus in the supplemented group was 60% and 90% in the deficient group. This conderisation of the nucleus is considered as apoptosis.In the rats, after over 30 minutes exposure to the blue light of 4.0*10^4 mW/m^2, ERGs a- and b-waves and oscillatory potentials showed significant decrease in the amplitudes. They showed dark recovery up to 14 days after the light exposure.The rabbits, after 7 days light exposure at 7000 lux, showed 22% decrease in the EOG amplitudeat 30 minute of light adaptation. Less