PURPOSE - When patients with glaucoma require cataract surgery, combined procedures offer important advantages over cataract surgery alone. Because mitomycin C has improved the success rate of a trabeculectomy in patients at high risk for filtration failure, the authors investigated whether it also would increase the survival rate of functioning filters in combined procedures.
METHODS - Patients with both cataract and glaucoma underwent combined mitomycin C trabeculectomy, extracapsular cataract extraction, and intraocular lens implantation. Mitomycin C (0.5 mg/ml) was applied topically to the trabeculectomy site for 5 minutes before the cataract extraction. Intraocular pressure (IOP), visual acuity, and astigmatism were measured preoperatively and postoperatively. One-year results are available for 74 patients.
RESULTS - At 1 year, 54 (73%) of 74 patients had IOPs of 15 mmHg or less without glaucoma medications. Visual acuity was 20/40 or better in 44 (60%) of 74 patients. Ten (15%) patients had a shift of more than 2 diopters of astigmatism against the rule compared with preoperative values. No notable corneal epithelial toxicity was present. Postoperative symptomatic hypotony with the wound construction occurred in 3 (4%) of 74 patients, with 1 patient requiring surgical revision. Other potential complications of mitomycin C include endothelial toxicity (1 patient had decreased vision due to endothelial folds) and wound stability (1 patient had wound rupture after direct ocular trauma).
CONCLUSION - The 1-year survival rate of a functioning trabeculectomy using mitomycin C in combined glaucoma and cataract surgery is encouraging. The longer-term benefits and possible adverse effects of mitomycin C in combined procedures are unknown and continue to be investigated.