Aim: To study the long-term efficacy and safety of modified viscocanalostomy in Chinese people with open angle glaucoma (OAG).
Methods: This retrospective study included a total of 100 eyes from 100 Chinese patients with medically uncontrolled OAG. All the patients underwent modified viscocanalostomy with injection of viscoelastic material in the surgically created ostia of Schlemm's canal (SC). The modifications included peeling of the inner wall of SC and the juxtacanalicular meshwork, use of mitomycin C, and loosely suturing the superficial scleral flap. Intraocular pressure (IOP), visual acuity, number of medications, laser goniopuncture data and complications were recorded. The definition of complete (qualified) success was an IOP equal to or lower than 21, 18, 16 mm Hg without (with or without) anti-glaucoma medications.
Results: The mean IOP was 33.5±9.9 mm Hg before surgery, 15.2±3.6 mm Hg (mean IOP reduction of 51%) at 5y after surgery, and 15.6±2.8 mm Hg (mean IOP reduction of 49.9%) at 10y after surgery (P<0.001). The number of anti-glaucoma medications dropped from 2.39±0.5 preoperatively to 0.47±0.8 at 5y and 0.67±0.8 at 10y postoperatively (P<0.001). The follow-up period was 104.5±37.0mo. The qualified success rate for an IOP of 21, 18 or 16 mm Hg or less was 84% [95% confidence interval (CI): 0.80-0.88], 73% (95%CI: 0.68-0.78), and 59% (95%CI: 0.52-0.66) after 5y, and 80% (95%CI: 0.76-0.84), 69% (95%CI: 0.64-0.74), 51% (95%CI: 0.44-0.58) after 10y, respectively. There was a relationship between age, preoperative IOP and success rate (P<0.01, P<0.05). A total of 31 eyes (31.3%) in 31 patients underwent laser goniopuncture, decreasing the IOP from 22.9±4.3 mm Hg to 16.3±2.5 mm Hg (P<0.01). Neither blebitis nor endophthalmitis occurred.
Conclusion: Modified viscocanalostomy could be performed to lower IOP, decrease multiple anti-glaucoma drops use as well. It's a safe procedure with less complications over 10y in Chinese individuals with OAG.
Keywords: Schlemm's canal; laser goniopuncture; non-penetrating glaucoma surgery; open angle glaucoma; viscocanalostomy.