Abstract
Purpose: :
To determine whether eyes with posterior vitreous detachment (PVD) induction by plasmin and/or SF6 treatment might have faster clearance of vascular endothelium growth factor (VEGF)
Methods: :
Study design included 4 groups of animals. Rabbit in group 1 received intravitreal injection of plasmin and SF6. Rabbit in group 2 received an intravitreal injection of plasmin only. Rabbit in group 3 received an intravitreal injection of SF6 only. Rabbit in group 4 received an intravitreal injection of balanced salt solution (BSS) injection and served as control. One month after plasmin or SF6 injection, injection of VEGF (50 ul, 10 pg/ul) was performed in study eyes and control eyes. Intravitreal samples were collected using a 27-gauge needle through the pars plana at the following time intervals: one day, 3 days, and 7 days to determine the residual vitreous concentration of VEGF.
Results: :
One day after VEGF injection, residual VEGF concentration in the vitreous cavity was significantly lower in the plasmin and SF6 treated eyes (group 1) and plasmin treated eyes (group 2) than the control eyes (group 4) (p<0.05). Three days after VEGF injection, residual VEGF concentration in the vitreous cavity was still significantly lower in the plasmin and SF6 treated eyes (group 1) than the control eye (group 4). Seven days after VEGF injection, residual VEGF concentration was very low and no statistically significance was noted among different treatment groups.
Conclusions: :
Eyes with complete PVD induction might have a faster clearance of exogenous VEGF. This implies a novel treatment direction for the VEGF-related retinopathies by plasmin enzyme.
Keywords: vascular endothelial growth factor • vitreoretinal surgery • vitreous