Sub-Tenon Atracurium Injection in Rabbit Eyes; a Histopathologic Study

PURPOSE: To evaluate early and late histopathologic changes following posterior sub-Tenon injection of atracurium in the rabbit eye. METHODS: This study was performed on 39 healthy white New Zealand rabbits which received sub-Tenon injection of 0.05-0.08 mg/kg atracurium diluted in 0.5 ml normal saline (N/S) in the left and 0.5 ml N/S in the right eyes. Bilateral enuclation was performed one hour after the injection to evaluate early changes in 19 rabbits and one week later to determine late changes in the remaining 20 animals. After enucleation, the rabbits were euthanized. Enucleated eyes were sent in 10% formalin solution for histopathologic examination. After processing, the specimens were evaluated by light microscopy following staining with hematoxylin and eosin, and trichrome. RESULTS: Congestion was more common in the control group 1 hour after injection. Liquifaction necrosis was seen in both groups but was significantly increased one week after the injection in the atracurium group. CONCLUSION: Congestion is a transient complication related to injection which disappears after one week, but necrosis seems to be an important late complication of atracurium injection.