PURPOSE:To determine the absorption and the release of mitomycin-C from a collagen implant and tissue impregnation in the anterior structures of the rabbit eye.METHODS:Determining the quantity of mitomycin-C that a collagen implant can absorb with the difference between dry and soaked weight. Mitomycin-C release was measured in vitro using spectrophotometry. The measurement was repeated using a bioassay. Ocular tissue impregnation was determined in 12 eyes of six rabbits. Sclera, implant, aqueous, and ciliary body specimens were collected for concentration measurement using HPLC from 1 to 6 h after surgery.RESULTS:The mean mitomycin-C quantity absorbed in the implant was 3.22+/-0.2 microg. In vitro release was 0.13 mg/ml after 10 min and 0.05 microg/ml at 6 h. The bioassay showed almost no antifibrotic activity in sclera. In vivo release of mitomycin-C was high from the first to the sixth hour.CONCLUSION:After filtering surgery, mitomycin-C in the collagen implant is clearly released and ocular tissues are effectively impregnated.
Purpose: To determine the absorption and the release of mitomycin-C from a collagen implant and tissue impregnation in the anterior structures of the rabbit eye.Methods: Determining the quantity of mitomycin-C that a collagen implant can absorb with the difference between dry and soaked weight. Mitomycin-C release was measured in vitro using spectrophotometry. The measurement was repeated using a bioassay. Ocular tissue impregnation was determined in 12 eyes of six rabbits. Sclera, implant, aqueous, and ciliary body specimens were collected for concentration measurement using HPLC from 1 to 6 h after surgery.Results: The mean mitomycin-C quantity absorbed in the implant was 3.22 +/- 0.2 mu g. In vitro release was 0.13 mg/ml after 10 min and 0.05 mu g/ml at 6 h. The bioassay showed almost no antifibrotic activity in sclera. In vivo release of mitomycin-C was high from the first to the sixth hour.Conclusion: After filtering surgery, mitomycin-C in the collagen implant is clearly released and ocular tissues are effectively impregnated.