Canaloplasty after failed trabeculectomy: a possible option.

Canaloplasty is usually indicated for eyes that have not undergone previous filtrating surgery for glaucoma. In some cases, however, "trabeculectomy" can be targeted anterior to the angle components, thus leaving Schlemm's canal integral and untouched. In the past 4 years of performing canaloplasty in our Glaucoma Clinic in Udine, a total of 6 eyes with previous failed trabeculectomy and elevated intraocular pressure (IOP) despite maximum tolerated medical therapy underwent canaloplasty. The preoperative IOP was 32.2±9.6 mm Hg, ranging from 25 to 48 mm Hg. In this group of patients, canaloplasty could be correctly completed in 5 cases; in 1 case, however, Schlemm's canal could not be cannulated for the entire 360-degree circumference, thus surgery was converted into viscocanalostomy. Follow-up ranged between 6 and 28 months (mean, 16.7±9.3 mo). The mean IOP at 6, 12, 18, and 24 months was 17.3, 15.4, 14.7, and 16.3 mm Hg, respectively. The number of medications used before and at the 2-year follow-up was 3.2±1.2 and 2.3±0.5, respectively. Our results suggest that canaloplasty can be considered as a possible surgical option in eyes with failed trabeculectomy showing undamaged Schlemm's canal from previous filtrating surgery.