HALF CORNEAL LIGHT SHIELD AS A DELIVERY SYSTEM FOR STANDARDIZED APPLICATION OF MITOMYCIN-C

Purpose: The authors develop a simple and economical method of applyin g reproducible intraoperative doses of mitomycin C for glaucoma filter ing surgery. Methods: A three-part protocol was developed to study sev eral properties of half corneal light shields (HCLSs). Part A tested t he amount of mitomycin C (0.4 mg/ml) absorbed, the expansion dimension s attained, and the amount released to filter paper. In part B, the in vitro release of mitomycin C to an enucleated pig eye was examined. I n part C, the in vivo release during intraoperative filtering surgery was tested. Results: The amount of mitomycin C solution absorbed by th e HCLSs ranged from 1.07 x 10(-2) mg to 1.19 x 10(-2) mg; expansion wi dth ranged from 6.8 mm to 7.0 mm; expansion height ranged from 3.6 mm to 3.8 mm; expansion thickness was constant at 0.6 mm. The amount of s olution released to filter paper ranged from 6.8 x 10(-3) mg to 8.6 x 10(-3) mg. The amount of solution transferred to the pig eye ranged fr om 1.0 x 10(-3) mg to 2.7 x 10(-3) mg. The amount of solution released in filtering surgery ranged from 2.0 x 10(-3) mg to 3.8 x 10(-3) mg. Conclusions: The contact surface area, the amount absorbed, and the am ount released by each HCLS was reproducible. The uniform thickness the oretically provides a uniform distribution of mitomycin C. This method may allow standardization of intraoperative mitomycin C application, and may reduce the incidence of complications.