advertisement
Abstract #8645 Published in IGR 5-1
Impact of irrigation in a new model for in vitro diffusion of mitomycin-C after episcleral application
Georgopoulos M; Vass C; Vatanparast ZCurrent Eye Research 2002; 25: 221-5
PURPOSE: Episcleral application of mitomycin C (MMC) during glaucoma surgery hinders postoperative wound healing, but may also lead to side-effects in the ciliary body. The authors present an experimental model to investigate the influence of irrigation on the diffusion of MMC through the sclera and into the subscleral compartments. MATERIAL AND METHODS: Scleral quadrants from ten human donor eyes were mounted on PMMA tubes filled with saline to imitate the intraocular fluid. Beneath the sclera, a subscleral sponge was fixed to mimic the ciliary body. The episcleral sides of the scleral quadrants were exposed to sponges soaked in 0.2 mg/ml MMC and thereafter irrigated with 0, 40, 100, and 200 ml saline. MMC concentrations in the sclera and subscleral compartments were analyzed by means of high-performance liquid chromatography. In a second experiment, after an application time of one minute, various free diffusion times until analysis were studied in order to evaluate the time-course of MMC penetration. RESULTS: MMC concentrations became weaker from the scleral layers (1-13 μg/m., depending on depth and irrigation) to the subscleral sponge (0.17-0.27 μg/ml), and the subscleral fluid (0.002-0.05 μg/ml). Irrigation significantly reduced MMC concentrations in the superficial scleral layers and in the subscleral fluid to 10-30% of the no-irrigation value. No effect was seen in the deep scleral layers and subscleral sponges. In the second experiment, the subscleral compartments showed higher MMC concentrations with longer diffusion times, whereas no effect on intrascleral MMC concentrations was observed. CONCLUSIONS: Irrigation reduced MMC concentrations in the superficial scleral layers and subscleral fluid by the same amount. The clinical value of irrigation should be reconsidered; a lower dose MMC application without irrigation might be a more rational approach.
Department of Ophthalmology, Medical School, University of Vienna, Vienna, Austria. michael.georgopoulos@akh-wien.ac.at
Classification:
12.8.10 Woundhealing antifibrosis (Part of: 12 Surgical treatment > 12.8 Filtering surgery)
