Abstract
Abstract: :
Purpose: To assess theoretical mitomycin C dose and kinetic release in collagen implants, and determine solution concentration to soak implants for optimal delivery in operation site without reaching toxic level. Methods:An eye anterior segment mock–up modelled filtration. A pump simulated aqueous secretion and water was collected upon exiting. Ten Staar collagen implants were soaked in 2mg/ml mitomycin C solution for 15 minutes. Implant mass was measured dry and after soaking, then implants were washed under 20 µl/min flow. Water was either collected each hour for 24 hours or at 10, 20 min, and then every 20 minutes for 8 hours. Mitomycin C concentration was then measured by spectrophotometer. Soaked implants were also inserted in 12 rabbit eyes after deep sclerectomy, and were left for 1, 2, 3 & 6 hours. Implant, scleral flap, aqueous and ciliary body were removed and mitomycin C measured by HPLC. Results: Implant mean weight was 0.63 mg dry, 2.2 mg soaked. Mean mitomycin C mass in implant was 3.22 µg. After 10 minutes implants were saturated with mitomycin C, concentration in draining water was 0.13 mg/ml at 10 minutes, 0.05 ug/ml at 6 hours, not detectable thereafter. Washing kinetic showed rapid diminution in the first 60 minutes. Washed–out was completed in 6 hours. Maximum mitomycin C dose in tissues was reached between 1 and 2 hours, and almost no dose reached ciliary bodyImplant mean weight was 0.63 mg dry, 2.2 mg soaked. Mean mitomycin C mass in implant was 3.22 µg. After 10 minutes implants were saturated with mitomycin C, concentration in draining water was 0.13 mg/ml at 10 minutes, 0.05 ug/ml at 6 hours, not detectable thereafter. Washing kinetic showed rapid diminution in the first 60 minutes. Washed–out was completed in 6 hours. Maximum mitomycin C dose in tissues was reached between 1 and 2 hours, and almost no dose reached ciliary body Conclusions: This experiment showed that mitomycin C could be delivered in a safe way and maybe more precise dose than with traditional sponge soaking method
Keywords: pharmacology • inflow/ciliary body • wound healing