Abstract
Abstract: :
Purpose: To evaluate the safety of dispase and plasmin when using by intravitreal injection in the rabbit eyes Methods: Forty–eight young pigmented rabbits were randomized into 6 groups. The rabbits received 0.025U/0.05ml (group1, 5), 0.1U/0.05ml (group2) of dispase, 1U/0.05ml (group 3, 6), 4U/0.05ml(group 4) of plasmin in experimental eyes. PBS 0.05ml was injected into the fellow eyes as control. The rabbits in group 5 and 6 were enthanized 15 minutes postoperatively for ocular histological examination. The others were followed with indirect ophthalmoscope and biomicroscopy 15, 30 minutes, 1,2,8 hours and 1,3,7 days postoperative. Ultrasonography and electroretinogram were performed 1 hour and 1, 7 days postoperative. Then their eyes were examined by scanning and transmission electron microscopy. Results: Partial or complete posterior vitreous detachment can be observed in the eyes received dispase and plasmin, proved by the results of scanning electron microscope. Light microscopy showed inflammation in both dispase and plasmin treated eyes of group 5 and 6. In dispase treated eyes, cell damage, preretinal hemorrhage and cateract were observed. Also in these eyes, the amplitudes of ERG a–wave and b–wave showed a significant reduction from baseline and the ultrastructure damage of retina were found by transmission electron microscopy. In plasmin treated eyes, the ERG and cell ultrastructure showed no significant changes. There is no change in control eyes. Conclusions: Intravitreal injection of dispase 0.025U or more can induce posterior vitreous detachment, but it is not safe. Plasmin is safer, except for the potential risk of inducing intraocular inflammation.
Keywords: drug toxicity/drug effects • vitreous • retina