Purpose: To investigate and compare the concentrations of carboplatins achieved in the aqueous and vitreous humors after intravenous or subconjunctivaly injection and to investigate whether local administration of carboplatin might result in higher concentrations in the aqueous and vitreous humor.
Methods: Four New Zealand rabbits were treated with carboplatin (18.7 mg/kg) in intravenous. The other 4 rabbits were injected with carboplatin (10 mg/ml 0.5 ml) in right eyes subconjunctivaly. The Samples of the aqueous and vitreous humors of rabbits were drawed at 1, 2, 3 hours after the end of infusion and measured the concentration of carboplatin with atomic absorption spectroscopy. The agent dose of systemic infusion were 8 fold for that in subconjunctival delivery.
Results: The concentrations of carboplatin in aqueous and vitreous humors treated with intravenous after 1, 2, 3 hours were 140, 330, 180 ng/ml and 20, 40, 17 ng/ml. The concentration of carboplatin in aqueous and vitreous humors treated with subconjunctively after 1, 2, 3 hours were 2,650, 4,390, 2,780 microg/ml and 160, 250, 110 ng/ml. There is statistical significance between the concentrations of carboplatin of aqueous and vitreous humor after intravenous and subconjunctival (P < 0.01).
Conclusions: The delivery of subconjunctival of carboplatin result in higher concentrations in aqueous and vitreous humors than intravenous administation. The result suggest that local delivery of chemotherapeutic drugs should elevate the intraocular drugs concentration and be effective for retinoblastoma treatment.