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）