[Does the dosage of mitomycin-C applied during filtering surgery of glaucoma vary with the individual surgeon?].
PURPOSE: The purpose of this study was to estimate the quantity of mitomycin-C contained in sponges prepared by different surgeons as compared to that in applicators of the type used in Schirmer's test graduation (5 x 5 mm). MATERIALS AND METHODS: Four surgeons each cut and prepared 10 sponges for intraoperative use according to their usual method. The same procedure was performed with 10 Schirmer's test graduations. Each sponge and each graduation was immersed in a solution of mitomycin-C 0.2 mg/ml, and the quantity of antibiotic (microgram) in each was calculated as the difference between wet and dry weight. RESULTS: The mean quantity (+/-SEM) of mitomycin-C contained in cut sponges was 9.6 +/- 4.4 micrograms (range 1.9-17.3), and differences between surgeons were statistically significant (p < 0.0001). The mean quantity of antibiotic in Schirmer's test graduation was 1.7 +/- 0.3 micrograms (range 1.1-2.5), and the differences between surgeons were not statistically significant (p = 0.79). CONCLUSION: The quantities of mitomycin-C contained in sponges prepared for glaucoma surgery differed for a given surgeon and between surgeons. Thus, variations in the doses applied to the sclera could account for certain complications due to mitomycin-C. The use of a Schirmer's test graduation improves predictability for the quantity of mitomycin-C applied to the sclera.