Changes of blood aqueous barrier after phacoemulsification in rabbits.

PURPOSE:To evaluate the function and the morphological changes of the blood aqueous barrier (BAB) after phacoemulsification and to provide the physiological mechanism of BAB dysfunction. METHODS:Phacoemulsification was performed on 12 rabbit eyes. Aqueous humor was abstracted and the concentrations of aqueous humor protein were examined preoperatively and on postoperative days 1, 7, 14, 21, 30 with Lowry. After the iris and the ciliary body were removed from the rabbit eyes, we selected lanthanum nitrate as a tracer, then ultrastructural changes of BAB were investigated with transmission electron microscopy. RESULTS:Highly statistically significant differences (P < 0.05) were found between preoperative aqueous humor protein concentration and those measured on days 1, 7, 14, 21 and 30 after surgery. Under transmission electron microscopy, a part of the endothelial cells and BAB damaged as shown by the leakage of lanthanum tracing into intravessels through the broad space were observed. CONCLUSION:The results suggest that there is a blood aqueous barrier breakdown after phacoemulsification. The morphological basis of BAB damage is the reversible opening of tight junctions between endothelial cells.