Viscocanalostomy: a pilot study

Viscocanalostomy is a new, non-penetrating procedure for glaucoma surgery. We started a prospective study to assess the effectiveness and safety of the operation. Materials and methods. Up to March 1998 we enrolled 33 patients (33 eyes) suffering from glaucoma, uncontrolled despite maximum medical therapy, who underwent viscocanalostomy according to Stegmann's technique. A complete ophthalmological examination was performed the day before surgery and on days 1 and 7 postoperatively. Further visits were scheduled at months 1, 3, 6 and 12.

In four eyes Schlemm's canal was either missed or not deroofed properly, and the procedure was converted into simple trabeculectomy. After a mean follow-up of 3.0 +/- 2.6 months (range 1-10), success defined as IOP > 2 and < 21 mmHg with no medication was obtained in 86.2% of the cases (25/29); 23 out of 29 eyes (79.3%) had IOP > 2 and < 16 mmHg. In the 25 successful eyes, mean IOP was 27.7 +/- 9.5 mmHg (range 13-48) preoperatively and 12.0 +/- 3.0 mmHg (range 7-18) (p < 0.0001) at the end of the follow-up period. Mean VA ranged from 0.35 +/- 0.34 to 0.32 +/- 0.32 (n.s.). Intraoperative complications included: Descemet rupture (7), with iris plugging in two cases; choroidal deroofing (3), irregular incision of Schlemm's canal (2). Postoperative complications included: self-resolving 2-mm hyphema (4); IOP spike (1); inadvertent filtering bleb (2); hypotony with choroidal detachment for one week (1).

In this short-term study, viscocanalostomy proved effective and safe in lowering IOP in glaucomatous eyes.