Impact of early and delayed Nd:YAG laser goniopuncture on results of deep sclerectomy (5-years follow up period)

Purpose: To report on impact of Nd:YAG laser goniopuncture (LGP) timing on hypotensive efficacy of deep sclerectomy (DS) for open-angle glaucoma (OAG) patients. Methods: 228 patients who underwent DS followed by Nd:YAG LGP between January 2010 and December 2013, (follow up – 5 years) were enrolled into a single-center, retrospective, non-randomized, consecutive study. Subjects were divided into two groups (1 – delayed LGP, n = 116; 2 – early LGP, n = 112). Demographic variables, preoperative glaucoma medications, preceding surgeries and glaucoma severity were analyzed. Intraoperative and postoperative complications, intraocular pressure (IOP), ultrasound biomicroscopy (UBM) values were recorded. Success rate was analyzed using Kaplan-Meier curve. UBM data were the criteria for early or delayed LGP. Results: LGP was performed 3.46 ± 1.9 (1.5–6.7) months after DS in group 1, 1.12 ± 0.08 (0.9–1.5) months in group 2 ( p = 0.0001). Mean IOP before LGP in group 1 was 18.5 ± 4.7 (11.2–22.9) mm Hg; 15.7 ± 4.1 (9.1–18.5) mm Hg in group 2 ( p = 0.001). Choroidal effusion occurred in 8.6% of group 1 and 3.5% of group 2 ( p = 0.0001). Postoperative IOP: 15.6 ± 4.6 (group 1) and 15.7 ± 4.3 mm Hg (group 2) at 12 months ( p = 0.98), 16.7 ± 4.3 and 14.9 ± 1.6 mm Hg at 24 months ( p = 0.004), 16.8 ± 3.9 and 14.5 ± 3.2 mm Hg at 60 months, respectively ( p = 0.0001). Complete success rates: 68.07% and 92.59% at 12 months, 40.7% and 75.8% at 24 months, 15.2% and 48.93% at 36, 48, 60 months in groups respectively ( p = 0.0001). Conclusion: Early LGP after DS excludes TDM influence on further formation of intrascleral canal cavity and outflow pathways demonstrating pronounced hypotensive success in a long-term follow-up.