The effect of mitomycin-C on postoperative corneal astigmatism in trabeculectomy and a triple procedure.

BACKGROUND AND OBJECTIVE

The authors attempted to determine the effect of mitomycin-C (MMC) on postoperative corneal astigmatism in patients who underwent trabeculectomy or a triple procedure (trabeculectomy, extracapsular cataract extraction, and intraocular lens implantation).

PATIENTS AND METHODS

Using the vector analysis method, the authors measured the postoperative induced astigmatism of 76 eyes in 59 patients who underwent trabeculectomy or a triple procedure with or without the application of MMC. Postoperative induced astigmatism corresponding to the 180 degrees axis was compared between the two groups.

RESULTS

The patients who underwent trabeculectomy with or without MMC showed a mean induced astigmatism of -1.01 D and -2.63 D, respectively, after 1 month (P < .05), and 0.34 D and -1.42 D after 12 months (P < .05). Those who underwent a triple procedure with or without MMC showed a mean induced astigmatism of -1.81 D and -4.50 D, respectively, after 7 days (P < .05), and 1.73 D and -0.13 D, respectively, after 12 months (P < .05). The entire amount of postoperative against-the-rule astigmatic shift was similar between the with-MMC group and the without-MMC group. The against-the-rule astigmatic shift of the group without MMC reached a plateau after 3 months. However, the group with MMC showed continuous against-the-rule astigmatic shift until 12 months.

CONCLUSION

This study suggests that MMC induces less with-the-rule astigmatism in early postoperative periods and continuous against-the-rule shift after 3 months following a trabeculectomy or a triple procedure.