Intraoperative Application Of Mitomycin Research Articles

Experiences with mitomycin C

Recently, encouraging results with the use of Mitomycin C in trabeculectomy have been reported. We used Mitomycin C (0.028%) during trabeculectomy in 72 eyes of 68 patients. Forty-one eyes have already been controlled during 6 months and 19 eyes during 9 months after the surgery. The mean intraocular pressure after 6 and 9 months was respectively 13 +/- 8 mm Hg and 13 +/- 10 mm Hg. The difference between these results and the preoperative values (27 +/- 9 mm Hg) were statistically significant after 6 and 9 months (p < 0.001). Despite frequent choroidal detachments (20 eyes), the visual acuity recovered during the follow-up to the preoperative values. In patients with uncertain prognosis for the intraocular pressure after trabeculectomy, the intraoperative application of Mitomycin C seems to improve considerably the operative success rate.

Cliniclal Experiences of Trabeculectomy with Mitomycin C

The use of intraoperative application of Mitomycin C at the filtration site has been known to improve the surgical outcome in glaucomatous eyes with high risk for failure of trabeculectomy. The author performed trabeculectomies with intraoperative Mitomycin C on 25 eyes of 20 patients with poor surgical prognosis to study the efficacy and safety of this technique in glaucomatous patients with high risk for failure of trabeculectomy. After the preparation of a scleral flap, 0.2mg/ml solution of Mitomycin C was applied between Tenon's capsule and the sclera for 2 minutes. The exposed area was then irrigated with 200 ml of balanced salt solution. The follow-up period was from 1 to 7 months (mean 3.8 months). The mean preoperative intraocular pressure (IOP) was . The mean final postoperative IOP was . Twenty three (88%) of the 25 eyes were successfully controlled with the IOP of less than or equal to 20 mmHg without glaucoma medication. There were early postoperative complications of hyphema in 5 eyes (20%), shallow anterior chamber in 4 eyes(16%), punctate keratopathy in 3 eyes (12%), aqueous leaking from conjunctival wound in 2 eyes (8%), encapsulated bleb in 1 eye (4%) and choroidal detachment in 1 eye (4%), and 4 eyes had long term hypotony lasting more than 2 months. Although Mitomycin C is simple to use and effective adjunct to trabeculectomy, further study will be needed to determine the mechanism of action, indication, dosage and optimal exposure time of Mitomycin C.

Trabeculectomy with Mitomycin C for Refractory Glaucoma in Blacks

The use of one intraoperative application of mitomycin C at the filtration site has been effective in eyes at increased risk for failure of routine trabeculectomy. To study the efficacy and safety of this technique in patients with refractory glaucoma, we prospectively examined 30 eyes of 26 black patients in whom a 0.2-mg/ml solution of mitomycin C was applied between Tenon's capsule and the sclera for five minutes before trabeculectomy. The results were compared to those found in a matched group of 30 eyes of 28 patients who underwent trabeculectomy without mitomycin C. The mean postoperative intraocular pressures were significantly lower in the mitomycin C group than in the control group (P = .001). Of the 30 eyes in the mitomycin C group, 25 (83%) had an intraocular pressure of less than 21 mm Hg without glaucoma medication, compared to 11 of 30 (37%) in the control group (P = .00006). In the mitomycin C group, 19 eyes (63%) developed a cystic avascular thin-walled filtering bleb, four eyes (13%) a late positive Seidel test, and one eye slight scleral thinning over the area where the mitomycin C was applied. Although mitomycin C is effective when used in this manner, further study is required to determine the long-term complications.

Effect of Topical Mitomycin C on Glaucoma Filtration Surgery in Monkeys

In this study, an experimental model of glaucoma filtration surgery was used to evaluate the clinical and histologic effects of a single intraoperative topical application of mitomycin C. Argon laser treatment to the trabecular meshwork produced sustained elevation of intraocular pressure in monkeys. Eight eyes of four animals were randomly assigned to receive topical mitomycin C or balanced salt solution at the time of full-thickness sclerostomy. Surgical success was substantially increased in four of five eyes that received mitomycin C when compared with three eyes that received topical balanced salt solution. Mitomycin C was also effective in prolonging surgical success in two eyes that had previously undergone surgery and failed. No significant ocular toxicity was observed in eyes treated with mitomycin C. Histologic examination of mitomycin C-treated eyes showed patent sclerostomies and hypocellular, well-formed bleb cavities. A single intraoperative application of mitomycin C has a marked effect on postoperative wound healing after filtration surgery in monkeys.

Potential Toxicity of Mitomycin C

To the Editor. —Chen et al1and Palmer2recently reported on the use of mitomycin C as adjunct chemotherapy during glaucoma filtration surgery. Both investigations followed similar protocols in which the episclera was soaked with a solution of 0.2 to 0.4 mg/mL of mitomycin C for 5 minutes before creating a sclerostomy. The authors concluded that a single, intraoperative application of mitomycin C favorably affected the outcome of trabeculectomy surgery. Although their studies have no concurrent control groups, two randomized controlled trials comparing fluorouracil with topical mitomycin are underway (Association for Research in Vision and Ophthalmology, 1991). No intraocular toxicity was reported using this protocol. Although retinal toxicity has been demonstrated after intravitreal injection of mitomycin C in the rabbit model,3no studies have addressed intraocular toxicity following injection into the anterior chamber. We studied the intraocular toxicity of mitomycin C following intracameral injection because of the