Canaloplasty With Intraoperative Low Dosage Mitomycin C: A Retrospective Case Series

Purpose: To evaluate the safety and preliminary efficacy of intraoperative mitomycin C (MMC) in conjunction with canaloplasty for the treatment of open-angle glaucoma. Methods: Observational case series. A microcatheter was used to viscodilate the full circumference of Schlemm canal and to place a trabecular meshwork tensioning suture. Low dosage MMC was applied beneath the superficial scleral flap before dissecting the second, deep scleral flap and accessing Schlemm canal. Qualifying preoperative intraocular pressures (IOPs) were at least 16 mm Hg with a historical maximum IOP of at least 21 mm Hg. Primary outcome measures including visual acuity and adverse events are reported for a 12-month postoperative period. Secondary outcome measures included IOP and glaucoma medication usage. Results: In 20 eyes of 20 consecutive patients, adverse events were generally transient and not sight threatening. With the use of MMC, there was an increased rate of hypotony as compared with reported results of prior canaloplasty studies. The mean logMAR best corrected visual acuity at baseline was 0.07 +/- 0.12 with a mean of 0.09 +/- 0.13 at 12 months (P = 0.679). Mean IOP decreased from a preoperative value of 23.4 +/- 4.3 mm Hg on 2.2 +/- 1.2 antiglaucoma medications to 13.4 +/- 4.3mm Hg on no medications at 12 months. At all intervals, IOP and medication use results were significantly reduced versus baseline (P < 0.001). Conclusions: The adjunctive use of MMC in canaloplasty is safe and effective.