Effect of microplasmin on the clearance of vitreous haemorrhage from an experimental model in rabbits

Abstract

Microplasmin is known to alter the structure of the vitreous gel. The current experiments were designed to assess its ability to enhance clearance of an experimentally induced vitreous haemorrhage, and to compare it to ovine hyaluronidase. Twenty-five rabbits were used for this experiment, divided into five groups; groups 1-3 are microplasmin-treated eyes with 25, 75 and 125 μg, respectively. Group 4 treated with 55 IU of hyaluronidase, while group 5 was treated with normal saline (control). Eyes were injected in the mid-vitreous with 0.05 ml of autologous blood obtained from the marginal ear vein. One week later, all the groups were injected with the test solution injected in mid-vitreous as stated above. Clearance of the vitreous haemorrhage was assessed weekly indirect ophthalmoscopy for 8 weeks. Microplasmin-treated eyes showed a significant clearance of the vitreous haemorrhage in a dose-dependent fashion, where group 3 (125 μg) had the highest clearance rate in comparison with control eyes. Hyaluronidase-treated eyes showed a similar clearance rate as group 3. In addition, group 3 showed a complete posterior vitreous detachment, which did not develop in hyaluronidase-treated eyes. Microplasmin may be a useful agent to accelerate the clearance of vitreous haemorrhage.