Two Year Functional and Structural Changes-A Comparison between Trabeculectomy and XEN Microstent Implantation Using Spectral Domain Optical Coherence Tomography

PreserFlo MicroShunt versus trabeculectomy: an updated meta-analysis and systematic review

PURPOSE

This meta-analysis compares PreserFlo (PF) and trabeculectomy (TB) in moderate-to-advanced glaucoma (defined by visual fields with a mean deviation (MD) worse than -6 dB). Key outcomes include success rates (qualified success is defined as a target IOP of less than 21 mm Hg or a 20% reduction from baseline at the endpoint, with or without medications. Complete success is achieving these targets without any medications), intraocular pressure (IOP), complications, reinterventions, needling, glaucoma medication reduction, retinal nerve fibre layer (RNFL), and visual field progression.

METHODS

We searched PubMed, Scopus, and Cochrane Central up to 13/01/24, including randomized and non-randomized studies with at least 2 months follow-up. Bias risk was assessed using ROB-2 for RCTs and ROBIN-I for non-RCTs. Publication bias was evaluated via funnel plots and Egger's regression.

RESULTS

Ten studies (n = 1833 eyes; 57.4% PF) were analyzed. Preoperative IOP was 22.1 mmHg; 56.1% had moderate-to-severe glaucoma. No significant differences were found in qualified (QSR) and complete success rates (CSR) between PF and TB. Trabeculectomy achieved better IOP outcomes (mean difference, MD 1.59 mmHg; p = 0.0004) and greater IOP reduction (MD -2.52 mmHg; p = 0.0003), but PF showed less visual field progression (MD -1.21; p = 0.03) and lower hypotony maculopathy risk (OR 0.30; p = 0.03). PF had a higher reintervention rate, particularly in patients without prior glaucoma surgery (OR 1.74; p = 0.02) or with primary open-angle glaucoma (OR 1.84; p = 0.04).

CONCLUSION

Trabeculectomy is more effective for uncontrolled glaucoma up to 2 years, while PF presents a lower risk of hypotony-related events and may benefit patients sensitive to visual field progression. Study strengths include detailed subgroup analyses and mid-term follow-up, with limitations noted in the number of RCTs.

KEY MESSAGES

What is known PreserFlo MicroShunt has been shown to provide an efficient surgical solution for intraocular pressure (IOP) control with a favourable safety profile. Compared to trabeculectomy thereis still contentious regarding the best surgical approach. What is new Trabeculectomy is more effective in uncontrolled glaucoma patients up to 2 years, particularly if lower target IOPs are considered. PreserFlo had lower hypotony-related events risk and may be preferred for patients sensitive to visual field loss. PreserFlo showed a higher risk of reintervention, especially without prior glaucoma surgery or primary open-angle glaucoma diagnosis.

Functional and Morphological Outcomes after Trabeculectomy and Deep Sclerectomy-Results from a Monocentric Registry Study

The aim of this study was to compare the effectiveness of trabeculectomy (TE) and deep sclerectomy (DS) in lowering intraocular pressure (IOP) and thereby preserving visual field and peripapillary retinal nerve fiber layer (RNFL) tissue in primary open-angle glaucoma (POAG) cases. IOP, number of IOP-lowering medications, visual acuity, mean defect of standard automated perimetry, and mean peripapillary RNFL thickness were retrospectively collected and followed up for 3 years after surgery. TE was performed in 104 eyes and DS in 183 eyes. Age, gender, laterality, IOP, number of medications, visual acuity, perimetry mean defect, and peripapillary RNFL thickness were equally distributed at baseline. Mean IOP decreased from 23.8 ± 1.4 mmHg and 23.1 ± 0.4 mmHg to 13.4 ± 0.6 mmHg (p < 0.001) and 15.4 ± 0.7 mmHg (p = 0.001) in the TE and DS groups, respectively. Mean defect remained stable (TE: -11.5 ± 0.9 dB to -12.0 ± 1.1 (p = 0.090); DS: -10.5 ± 0.9 dB to -11.0 ± 1.0 dB (p = 0.302)), while mean peripapillary RNFL thickness showed further deterioration during follow-up (TE group: 64.4 ± 2.1 μm to 59.7 ± 3.5 μm (p < 0.001); DS group: 64.9 ± 1.9 μm to 58.4 ± 2.1 μm (p < 0.001)). Both TE and DS were comparably effective concerning postoperative reduction in IOP and medication. However, glaucoma disease further progressed during follow-up.

PRESERFLO MicroShunt implantation versus trabeculectomy for primary open-angle glaucoma: a two-year follow-up study

BACKGROUND

To compare the intermediate-term efficacy of PRESERFLO (PF) MicroShunt implantation with trabeculectomy (TE) in patients with primary open-angle glaucoma, focusing on longitudinal changes of functional and structural parameters.

METHODS

This retrospective comparative study included 104 eyes of 104 patients who underwent TE and 83 eyes of 83 patients that underwent PF implantation between January 2019 and December 2020, with a minimum follow-up of two years. Baseline and postoperative intraocular pressure (IOP), number of IOP-lowering medications, visual field mean defect (MD) and peripapillary retinal nerve fibre layer (RNFL) thickness measured using optical coherence tomography were assessed and compared between groups.

RESULTS

Baseline characteristics (age, sex, IOP, number of IOP-lowering medications, MD, RNFL thickness) were comparable between the two groups (all P > 0.05). During the two-year of follow-up, mean IOP decreased from 24.09 ± 1.15 mmHg and 21.67 ± 0.77 mmHg to 11.37 ± 1.13 mmHg (P < 0.001) and 15.50 ± 1.54 mmHg (P = 0.028), and the mean number of IOP-lowering medications decreased from 3.25 ± 0.14 and 3.51 ± 0.14 to 0.53 ± 0.14 (P < 0.001) and 1.06 ± 0.43 (P < 0.001) in the TE and PF groups, respectively. MD remained stable [- 11.54 ± 0.93 dB and - 11.17 ± 1.66 to - 10.67 ± 0.91 dB (P = 0.226) and - 10.40 ± 4.75 dB (P = 0.628) in the TE and PF groups, respectively] but RNFL thickness decreased continuously during follow-up [62.79 ± 1.94 µm and 62.62 ± 2.05 µm to 57.41 ± 1.81 µm (P < 0.001) and 60.22 ± 1.98 µm (P = 0.182) in the TE and PF groups, respectively].

CONCLUSION

PF implantation is comparably effective in the intermediate term in lowering IOP and reducing the use of IOP-lowering medications over a two-year follow-up period. Although visual field defects were stable, RNFL continued to decrease during postoperative follow-up.