Modified viscotrabeculotomy versus modified trabeculotomy in late-onset primary congenital, juvenile, and secondary open-angle glaucoma

Abstract

Purpose To compare modified viscotrabeculotomy (VCO-Tbo) to modified trabeculotomy (Tbo) in late-onset primary congenital, juvenile open-angle, steroid-induced, and pigmentary glaucoma. Methods Patients were randomly assigned to VCO-Tbo and Tbo groups in this study. Intraocular pressure (IOP), antiglaucoma medications, and success/failure rates were assessed. A linear mixed model was used to compare the change trend at different follow-up times. Survival time was evaluated using the Kaplan-Meier graph and Log-Rank test. Results The mean IOP at 1, 3, and 12 months in the VCO-Tbo group was 14.1 ± 3.1, 15.9 ± 3 and 17 ± 3.1 mmHg, respectively. The mean IOP at the same time points in the Tbo group was 15.9 ± 3.3, 17.6 ± 3.5 and 18.4 ± 3.2 mmHg (P = 0.051, 0.058, 0.088, respectively). The VCO-Tbo group had significantly lower IOP after six months (16.5 ± 4.1 mmHg vs. 18.7 ± 3.8 mmHg; p = 0.031) and by the last visit (16.8 ± 2.1 mmHg vs. 18.8 ± 2 mmHg; p = 0.013). The reduction in the number of medications was significant in both groups compared to baseline (P < 0.001), but there was no significant difference between groups (P = 0.450). The complete and qualified success rate was 43.9% and 34.1% in the VCO-Tbo group and 46.8% and 10.6% in the Tbo group at the final follow-up (p = 0.040, and 0.039, respectively). Conclusion Both procedures are effective in IOP and medication reduction. The survival time and efficacy of modified trabeculotomy can be augmented by injecting cohesive viscoelastic in the Schlemm's canal.