To evaluate the influence of learning curve on the surgical outcome of viscocanalostomy.
Retrospective, interventional study. Chart review of the first consecutive open-angle glaucoma cases that received viscocanalostomy in 1 institution between July 1996 and June 2000. Overall success was defined as no visual field deterioration; postoperative intraocular pressure (IOP) ≤20 mm Hg; and IOP reduction ≥30% compared with baseline values with or without medication. When medications were not required, success was defined as complete. Demographic, procedural, and postoperative data were tabulated and analyzed. Primary outcome measures: overall and complete success rates. Secondary outcome measures: number of glaucoma medications and surgical complications.
A total of 180 cases were analyzed. Mean follow-up (±SD) was 28.9±5.9 months (range, 12-36 mo). Overall success has significantly improved from 64% to 91% when comparing the first 45 to the last 45 cases of the series (Mantel-Cox, P=0.005). Similarly, complete success has significantly improved from 38% to 73% (Mantel-Cox, P=0.004). The mean number of glaucoma medication (±SD) significantly decreased from 2.58±0.94 before surgery to 0.53±0.79 after surgery (Wilcoxon, P<0.001). Surgical complications decreased from 16 in the first 45 cases to 10 in the last 45 cases without reaching statistical significance (Pearson χ2, P=0.315).
Viscocanalostomy appears to safely reduce IOP in cases with medically uncontrolled open-angle glaucoma. Mastering viscocanalostomy procedure is achievable after the first 40 cases.