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).