Filtering surgery with mitomycin-C in uncomplicated (primary open angle) glaucoma

Mitomycin is an antibiotic with antineoplastic activity which inhibits fibroblast proliferation in the operative field in glaucoma filtering surgery. The authors retrospectively evaluated the effectiveness of trabeculectomy with mitomycin-C as an initial surgical procedure in uncomplicated (primary open angle) glaucoma in 17 eyes of 17 patients; 12 eyes of 12 patients that received standard trabeculectomy constituted the control group. Mitomycin was applied at a concentration of 0.5 mg/ml for 3 min to the episclera and 2 min under the scleral flap. Median values for preoperative intraocular pressure was 43 mmHg (range 26-65) in the control group and 40 mmHg (range 30-60) in the mitomycin group (p > 0.05, Mann-Whitney U-test). After an average follow-up of 17 months, median postoperative IOP was 10 mmHg (range 3-18) in the control group and 4 mmHg (range 1.1-20) in the mitomycin group (p < 0.05, Mann-Whitney U-test). Percentage IOP drop was 75.6% in the control group (range 30.8-93.5%) and 89.6% (range 54.2-98%) in the mitomycin group (p < 0.05, Mann-Whitney U-test). The postoperative visual acuities of the two groups did not differ significantly (p > 0.05, Fisher exact test). Although there was not a statistically significant difference between complications, such as elevated intraocular pressure, wound leakage or bleb ulceration in both groups (p > 0.05, Fisher exact test), the number of hypotonous eyes (having an average IOP < or = 5 mmHg) was significantly higher in the mitomycin-C group compared to the controls (p < 0.05, Fisher exact test). Mitomycin established a well formed bleb and reduced the IOP more effectively than did the standard filtering procedure (p < 0.05, Mann-Whitney U-test); however, further work is necessary to evaluate the long-term complications of mitomycin-C surgery such as hypotony. This would help clear any doubts about the safety of this procedure on long-term.