[Follow-up of a pilot study of trabeculectomy with low dosage mitomycin C (0.2 mg/ml for 1 minute). Independent evaluation of a retrospective nonrandomized study].

BACKGROUND

The application of anti fibroses agents during glaucoma surgery leads to more satisfactory results with lower i.o. pressure, yet eliciting complications in wound healing, avascular filtering blebs and frequent chronic hypotonias. In patients with lower risk for failure a reduction of concentration and application time of Mitomycin C should minimise side effects while maintaining the beneficial effect of lower intraocular pressure.

PATIENTS AND METHODS

34 eyes of 32 patients (age 72 +/- 8) underwent trabeculectomy (14 combined with phacoemulsification and implantation of a foldable posterior chamber lens). During filtering surgery, Mitomycin C (0.2 mg/ml for 1 min) was applied after preparation of the scleral flap. An 11.5 +/- 5.0 (3-21), month followup, 30 (34) eyes (88.2%) had an i.o. pressure of < or = 21 mm Hg (14.0 +/- 4.3 mm Hg at the last control) without additional glaucoma medications.

RESULTS

The majority of filtering blebs (30/34; 88.2%) were well vascularised, often showing polycystic degenerations near the limbus. Only 3 eyes developed an avascular filtering bleb. No persisting leaks were observed and only 2 of 34 eyes (5.9%) developed short transient hypotonia (IOP < 6 mm Hg).

CONCLUSIONS

Adjunctive treatment with low concentration of Mitomycin C during filtering surgery results in good i.o. pressure with little risk of avascular bleb development. A prospective, randomised trial is required to assess the safety and efficacy of adjuvantive Mitomycin C treatment in low risk filtering surgery.