Objective To further investigate pathologic mechanism of retinal phototrauma. Methods Twenty Wistar rats were divided into control and experimental groups.Their eyes were extracted in 12，24 and 36 hours after light exposure.HE stained retina samples were examined and TDT-mediated dUTP nick end labelling(TUNEL)method was employed to distinguish apoptotic cells. Results After 12-hour light exposure,slight vesiculation was observed in the rod outer segment of the retinas.After 24-hour light exposure,the outer nuclear layer showed predominant fractured and condensed nuclei and fragmented DNA.After 36-hour light exposure,the rod outer and inner segments were lysed and most of the nuclei in the outer nuclear layer were disappeared. Conclusions Apoptosis of photoreceptor cell is one of the important mechanisms which cause experimental retinal photoinjury of rats. (Chin J Ocul Fundus Dis, 1999, 15: 167-169)
In order to explore retinal toxicity and to estimatequot;safe dosagequot;of intravitreal gentamicin 21 Dutch-belted rabbits divided into 5 dosage groups and 1 control group were investigated.The results showed that, in 3 000mu;g group, optic disc swelling and vein dilating were observed ophthalmoscopieally. Histopathologie study displayed the retinal necrolysis. In 50~500mu;g groups,the retinal pigment change was revealed within 3~14 days after the injection.Histopathologic study displayed that the retinal damages were confined in outer layers of retina in early stage. Inner layers of retina were also influenced in late stage. The results demontrated that with increasing intravitreal gentamiein,retinal damages are gradully aggravated,and even if intravitreal gentamicin was in minimum dose,retinal damages was still observed. （Chin J Ocul Fundus Dis,1994,10:167-169）
In order to explore the histochemical changes in retina after intravitreal injection of gentamycin,a histochemical quantitative analysis of cytochrome oxidase(CYO)and acetylcholinesterase(ACHE)was performed with a computerized image analysis system and was compared with that of morphological study.The results showed that CYO decreased significantly in 100mu;g dosage group.With increasing intravitreal gentamycin dosage or observed days,CYO decreased gradually in all rabbits.In 100~500mu;g dosage groups,ACHE changed mildly at 3 days of injection.It decreased significantly at 7 days.However,it was destroyed completely in 1000~3000mu;g dosage groups at 3 days. （Chin J Ocul Fundus Dis,1994,10:232-235）