Abstract
Purpose: :
Investigation of difference in pharmacokinetics after intravitreal injection of IgG in the different site of the vitreous cavity.
Methods: :
For examination of pharmacokinetics in the vitreous, 0.05 ml of the FITC labeled goat anti-mouse IgG (100 µg/ml) was injected from the superior pars plana to the vitreous cavity of the rabbit eye. A newly developed intravitreal injection guide was used to fix the tip of the injection needle in the superior-anterior vitreous (anterior injection group), and posterior vitreous (posterior injection group). One hour, one day and seven days after injection, the eye was enucleated and frozen. The vitreous was cut into five sections: superior-anterior, superior-middle, inferior-anterior, inferior-middle, and posterior vitreous. Fluorescent intensity was measured in each section to determine the concentration of the IgG.
Results: :
One hour after the injection, the concentration of the IgG in the posterior group was 6.8 +/-2.7µg/ml which is significantly higher than 2.2 +/-1.4µg/ml in the anterior group (p<0.05). One day after injection, the concentration was not different in the posterior vitreous between the two groups. However the concentration in the superior vitreous was higher than in the inferior vitreous in both groups. Seven days after injection, the drug was diffusely spreaded in both groups.
Conclusions: :
Intravitrealy injected IgG was likely to stay around the injected site . It takes more than a day to spread diffusely in the vitreous.
Keywords: drug toxicity/drug effects • vitreous • retina