Short-term safety and efficacy of Preserflo™ Microshunt in glaucoma patients: a multicentre retrospective cohort study

Additional Guidance on the Use of the PRESERFLO™ MicroShunt in the Treatment of Glaucoma: Insights from a Second Delphi Consensus Panel

INTRODUCTION

The PRESERFLO™ MicroShunt (PMS) has been proven to significantly lower intraocular pressure (IOP) in patients with glaucoma and has been available for use since 2019. With increasing published evidence and growing experience of glaucoma surgeons, the aim of this modified Delphi panel was to build on the findings of a previous Delphi panel conducted in 2021 and provide further guidance on the role of the PMS to treat patients with glaucoma in Europe.

METHODS

Thirteen European glaucoma surgeons experienced in the PMS procedure participated in a 3-round modified Delphi panel. A targeted literature review and expert steering committee guided Round 1 questionnaire development. Consensus was pre-defined at a threshold of ≥ 70% of panellists selecting 'strongly agree'/'agree' or 'strongly disagree'/'disagree' for 6-point Likert scale questions or ≥ 70% selecting the same option for multiple or single-choice questions. Questions not reaching consensus were restated/revised for the next round, following guidance from free-text responses/scoping questions.

RESULTS

In total, 28% (n = 9/32), 52% (n = 16/31) and 91% (n = 10/11) of statements reached consensus in Rounds 1, 2 and 3, respectively. There was agreement that the PMS may be used in patients with pigmentary, post-trauma or post-vitrectomy glaucoma and for patients with uveitic glaucoma without active inflammation. The PMS may be more suitable for patients with contact lenses than other subconjunctival filtering surgeries, without eliminating bleb-associated risks. Consensus was reached that combining PMS implantation and phacoemulsification may be as safe as standalone PMS surgery, but further efficacy data are required. Following a late rise in IOP ≥ 4 months post-surgery, topical aqueous suppressant drops or bleb revision may be suitable management options.

CONCLUSIONS

This Delphi panel builds on the considerations explored in the 2021 Delphi panel and provides further detailed guidance for glaucoma surgeons on the use of the PMS, reflecting the availability of novel evidence and surgical experience. Videos are available for this article.

Intermediate-term impact on corneal endothelial cells and efficacy of Preserflo MicroShunt implantation in patients with open-angle glaucoma - a prospective study over two years

INTRODUCTION

Preserflo MicroShunt is a novel microinvasive bleb forming device for the treatment of primary open-angle glaucoma. The intermediate- and long-term success and the impact of this procedure on corneal endothelial cell density remain to be investigated.

METHODS

In this prospective observational study, 62 eyes of 55 glaucoma patients (mean age ± SD: 67.0 ± 15.0 years) receiving a Preserflo MicroShunt were included. Corneal endothelial cell density, intraocular pressure and best corrected visual acuity were assessed preoperatively and at 3, 6, 9, 12, 18 and 24 months postoperatively. Success rates, bleb revision rates and complications were analysed. Complete success was defined as an intraocular pressure reduction of ≥ 20% and achieving a target pressure of ≤ 18, ≤ 15 or ≤ 12 mmHg without antiglaucoma medication. Qualified success indicated that the criteria were reached with or without medication.

RESULTS

Corneal endothelial cells showed no significant decline over 24 months (p > 0.05). Intraocular pressure showed a substantial reduction postoperatively (p < 0.001), decreasing from 29.6 ± 8,3 mmHg to 13.0 ± 4.3 mmHg after 24 months (p < 0.001). Complete and qualified success with a target pressure ≤ 15 mmHg was achieved in 52.9% and 54.6% of cases after 24 months, respectively. Best corrected visual acuity did not change after 24 months.

CONCLUSION

Preserflo MicroShunt had no negative side effects on corneal endothelial cells and showed favourable success rates after 2 years in patients with open-angle glaucoma.

PRESERFLO MicroShunt in Severe Myopia: A Case Report and Review of the Literature

The PRESERFLO™ MicroShunt (MP; Santen Inc., Osaka, Japan) is a minimally invasive bleb surgery (MIBS) manufactured to treat primary open-angle glaucoma (POAG), with lower postoperative adverse effects than with conventional filtering surgeries. We describe here the case study of a 58-year-old woman who presented with bilateral severe myopia with bilateral advanced POAG and unreached target pressure under quadritherapy, who was successfully managed by PM surgery. A review of the literature completes our observation. At presentation, the patient had a spherical equivalent of - 7.50 RE and - 7.75 LE with an IOP of 22 mmHg right and left eye (RLE) under quadritherapy, and with severe bilateral visual field loss, including scotomas within the central 5°. The patient presented with systemic hypertension treated with an antihypertensive drug. Two selective laser trabeculoplasties (SLT), performed 3 months apart, were first tried on the LE, without any change in IOP at 2 months. After considering the high risk of postoperative complications, a PM operation was proposed, with a targeted IOP in the mid-fifteens RLE. The patient's eyes underwent PM surgery with mitomycin C (MMC) MMC0.2 mg/mL for 3 minutes without any complications. The LE required 2 consecutive needlings with 1 mL MMC0.2 mg/mL. At 24 months after surgery, the two eyes gave successful results without the need for any additional medical therapy, and with well-functioning conjunctival blebs. The PM was an effective alternative to the gold standard trabeculectomy in our severely myopic patient. A comparative study between conventional filtering operations and this MIBS in highly myopic patients would confirm our observation.

Preserflo TM MicroShunt implantation combined with Ologen TM in primary and secondary glaucoma patients in a clinical setting

PURPOSE

This study aims to assess the effectiveness and safety of combining the Preserflo™ MicroShunt implant (MicroShunt) with a simultaneous Ologen™ implant in patients with glaucoma.

METHODS

We conducted a retrospective study on consecutive patients with medically uncontrolled glaucoma who underwent MicroShunt + Ologen implantation as a standalone procedure or in combination with phacoemulsification (combined procedure). Success was defined as achieving an intraocular pressure (IOP) of 6-15 mmHg at 18 months post surgery, with a preoperative IOP reduction of at least 20%, and without (complete success) or with (qualified success) the need for antiglaucoma medications. The primary endpoint was the success rate.

RESULTS

Forty-eight eyes from 47 patients were included, with 28 eyes (58.3%) undergoing the standalone procedure and 20 eyes (41.7%) undergoing the combined procedure. Overall, there was a significant reduction in preoperative IOP from 19.7 ± 5.8 mmHg to 11.4 ± 2.6 mmHg at 18 months ( P < 0.0001). In the standalone procedure group, preoperative IOP decreased from 21.5 ± 5.2 mmHg to 11.7 ± 2.5 mmHg ( P < 0.0001), and in the combined procedure group, preoperative IOP decreased from 17.1 ± 5.8 mmHg to 10.9 ± 2.7 mmHg ( P = 0.0002), with no significant difference between the two groups regarding final IOP. The mean number of antiglaucoma medications significantly decreased from 3.2 ± 1.1 to 0.3 ± 0.7 in the overall study population ( P < 0.0001). At 18 months, 40 eyes (83.3%) were classified as successful. Regarding safety, out of the total number of eyes, two (4.2%) experienced choroidal detachment without visual impairment, two (4.2%) had transient hyphema, one (2.1%) showed reactivation of a corneal herpetic ulcer, one (2.1%) had diplopia, and one (2.1%) exhibited a shallow anterior chamber during the first week.

CONCLUSION

The combination of Ologen™ and Preserflo™ MicroShunt, either alone or in conjunction with phacoemulsification, demonstrated a favorable profile in terms of IOP reduction and safety.

Risk Factors for Failure in Glaucoma Patients Undergoing Microshunt Implantation

PURPOSE

To evaluate risk factors for failure of Microshunt in glaucoma patients.

DESIGN

Multicenter retrospective cohort study.

METHODS

The study included 220 eyes from 220 consecutive glaucoma patients undergoing Microshunt implantation at six glaucoma units. Four intraocular pressure (IOP) success criteria were defined: (A) IOP ≤21 mm Hg with ≥20% IOP reduction; (B) IOP ≤18 mm Hg with ≥20% IOP reduction; (C) IOP ≤15 mm Hg with ≥25% IOP reduction; and (D) IOP ≤12 mm Hg with ≥30% IOP reduction from baseline. Kaplan-Meier analysis was used to estimate success rates according to the criteria above, and multivariable Cox models were used to identified risk factors for failure according to criterion A.

RESULTS

Success rates varied based on different criteria, ranging from 43.3% to 62.5% (overall success for criteria D and A, respectively) and from 35.3% to 44.4% (complete success for criteria D and A, respectively) at 1-year follow-up. Higher intraoperative MMC concentration was associated with reduced risk of failure to maintain complete (0.4 vs 0.2 mg/mL: hazard ratio [HR] = 0.441, P < .001) and overall (0.4 vs 0.2 mg/mL: HR = 0.360, P = .004) success. For complete success, other risk factors for failure were pseudoexfoliation glaucoma/pigmentary glaucoma (HR = 1.641, P = .004), primary angle closure glaucoma (HR = 1.611, P < .001), and previous non-glaucomatous ocular surgeries (HR = 2.301, P = .002). For overall success, other risk factors for failure were lower preoperative IOP (for 1-mm Hg increase, HR = 0.934, P = .005), higher number of preoperative antiglaucoma agents (HR = 1.626, P < .001), and Microshunt combined with cataract surgery (HR = 1.526, P = .033).

CONCLUSIONS

This study identified risk factors for Microshunt failure, highlighting the importance of high intraoperative MMC dose and careful patient selection to optimize surgical success.

Changes in Ocular Biometry Following PreserFlo MicroShunt Implantation and Trabeculectomy: A Prospective Observational Study

Background This study aimed to evaluate postoperative changes in ocular biometry following initial PreserFlo MicroShunt implantation and trabeculectomy. Methodology This prospective, observational study analyzed 27 cases of PreserFlo MicroShunt implantation and 29 cases of trabeculectomy performed by a single surgeon. Visual acuity, intraocular pressure, corneal curvature, central corneal thickness, anterior chamber depth, and axial length were assessed at baseline and postoperatively at one day, one week, two weeks, one month, two months, three months, and six months. Patients requiring additional surgery and those with missing data were excluded. Consecutive data were compared with the baseline values using multiple comparisons. Results In both groups, intraocular pressure was significantly decreased from baseline at all postoperative time points (all p < 0.01). Visual acuity decreased in both groups at one day and one week postoperatively. Corneal curvature remained unchanged in both groups throughout the six-month follow-up. Central corneal thickness increased at one day and one week postoperatively in the PreserFlo group, but not in the trabeculectomy group. Anterior chamber depth exhibited a significant decrease at one week postoperatively in both groups. Axial length significantly decreased postoperatively until three months in the PreserFlo group and at all postoperative time points in the trabeculectomy group. Conclusions Ocular biometry following PreserFlo and trabeculectomy had a similar tendency postoperatively.

Hypotony Failure Criteria in Glaucoma Surgical Studies and Their Influence on Surgery Success

PURPOSE

Review hypotony failure criteria used in glaucoma surgical outcome studies and evaluate their impact on success rates.

DESIGN

Systematic literature review and application of hypotony failure criteria to 2 retrospective cohorts.

PARTICIPANTS

A total of 934 eyes and 1765 eyes undergoing trabeculectomy and deep sclerectomy (DS) with a median follow-up of 41.4 and 45.4 months, respectively.

METHODS

Literature-based hypotony failure criteria were applied to patient cohorts. Intraocular pressure (IOP)-related success was defined as follows: (A) IOP ≤ 21 mmHg with ≥ 20% IOP reduction; (B) IOP ≤ 18 mmHg with ≥ 20% reduction; (C) IOP ≤ 15 mmHg with ≥ 25% reduction; and (D) IOP ≤ 12 mmHg with ≥ 30% reduction. Failure was defined as IOP exceeding these criteria in 2 consecutive visits > 3 months after surgery, loss of light perception, additional IOP-lowering surgery, or hypotony. Cox regression estimated failure risk for different hypotony criteria, using no hypotony as a reference. Analyses were conducted for each criterion and hypotony type (i.e., numerical [IOP threshold], clinical [clinical manifestations], and mixed [combination of numerical or clinical criteria]).

MAIN OUTCOME MEASURES

Hazard ratio (HR) for failure risk.

RESULTS

Of 2503 studies found, 278 were eligible, with 99 studies (35.6%) lacking hypotony failure criteria. Numerical hypotony was predominant (157 studies [56.5%]). Few studies used clinical hypotony (3 isolated [1.1%]; 19 combined with low IOP [6.8%]). Forty-nine different criteria were found, with IOP < 6 mmHg, IOP < 6 mmHg on ≥ 2 consecutive visits after 3 months, and IOP < 5 mmHg being the most common (41 [14.7%], 38 [13.7%], and 13 [4.7%] studies, respectively). In both cohorts, numerical hypotony posed the highest risk of failure (HR, 1.51-1.21 for criteria A to D; P < 0.001), followed by mixed hypotony (HR, 1.41-1.20 for criteria A to D; P < 0.001), and clinical hypotony (HR, 1.12-1.04; P < 0.001). Failure risk varied greatly with various hypotony definitions, with the HR ranging from 1.02 to 10.79 for trabeculectomy and 1.00 to 8.36 for DS.

CONCLUSIONS

Hypotony failure criteria are highly heterogenous in the glaucoma literature, with few studies focusing on clinical manifestations. Numerical hypotony yields higher failure rates than clinical hypotony and can underestimate glaucoma surgery success rates. Standardizing failure criteria with an emphasis on clinically relevant hypotony manifestations is needed.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found after the references.

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.

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

The development of minimally invasive glaucoma surgeries (MIGSs) was intended to provide safe and modestly efficacious modalities for early intervention of mild-to-moderate glaucoma, with minimal trauma and rapid recovery. They were mainly ab interno procedures that reduce intraocular pressure by facilitating the aqueous outflow by bypassing the trabecular meshwork resistance, reinforcing the uveoscleral flow via the supraciliary space, and reducing aqueous production by the ciliary body. While the cumulating evidence helps shape the role of the available MIGS, the exponential new development and advancement in this field has expanded the territory of MIGS. Apart from developing subconjunctival MIGS filtration devices (Xen gel stent and PRESERFLO MicroShunt), there is a tendency to revisit the "traditional" MIGS for alternative use and to modify the procedures with consideration of the fundamental aqueous outflow physiology. Combined MIGS has also been suggested, based on the theory that their different mechanisms may provide additive or synergistic effects. The advancement of laser procedures is also promising and could supplement unmet needs along the glaucoma treatment algorithm. This review examines the broad array of MIGS, updates the recent findings, discusses their potential alternative applications, and explores future challenges.

XEN 45 Gel Stent Implantation in Open Angle Glaucoma: 5-Year Results of a Prospective Study

PRCIS

XEN 45 Gel Stent is safe and effective for 3 years. The study results provide useful insight into the outcome of XEN 45 Gel Stent surgery over 5 years in daily clinical practice.

PURPOSE

To evaluate 5-year outcomes of XEN 45 gel stent implantation (XEN) in patients with open angle glaucoma.

METHODS

This is a prospective, single-center, interventional study. XEN implantation either alone (XEN) or combined with phacoemulsification (Phaco + XEN) was performed on 170 consecutive eyes (126 patients) with uncontrolled intraocular pressure (IOP) or disease progression despite medical treatment. "Complete" surgical success at 60 months was defined as unmedicated IOP ≤15 mm Hg and a relative IOP reduction ≥20% from medicated baseline, while "qualified" success allowed fewer ocular hypotensive medications than at baseline. Other definitions of success with various IOP targets were also analyzed. Secondary outcomes included mean IOP and IOP-lowering medication changes and rates of reoperations.

RESULTS

Mean age was 78.1±9.2 years, and 70.3% were female. Mean medicated IOP decreased from 19.8±7.7 mm Hg [19.6±7.1 (XEN) vs. 19.8±7.0 mm Hg (Phaco+XEN)] at baseline to 12.6±3.1 mm Hg [12.5± 3.1 (XEN) vs. 12.6±3.1 (Phaco+XEN)] at 5 years (-37.0%; P < 0.001). Medications decreased from 2.0±1.3 [2.0±1.3 (XEN) vs. 2.0±1.3 (Phaco+XEN)] to 0.8±1.1 [0.8±1.1 (XEN) vs. 0.8±1.1 (Phaco + XEN)] (-60%; P <0.001). Needling was performed in 84 eyes (49%), and 19.4% underwent a secondary surgical intervention. Complete success at 3 years was a strong predictor of success at 5 years (odds ratio: 3.06, P <0.01), while needling was associated with higher rates of failure (odds ratio: 3.6, P <0.01).

CONCLUSIONS

At 5 years, XEN gel stent implantation was a safe procedure and achieved clinically meaningful IOP and medication reduction. Success at 3 years is a predictor of success at 5 years. Needling correlates with higher failure rates.

PRESERFLO ™ MicroShunt versus trabeculectomy: 1-year results on efficacy and safety

PURPOSE

To compare the efficacy and safety of the PRESERFLO™ MicroShunt versus trabeculectomy in patients with primary open-angle glaucoma (POAG) after one year.

PATIENTS AND METHODS

Institutional prospective interventional cohort study comparing eyes with POAG, which had received the PRESERFLO™ MicroShunt versus trabeculectomy. The MicroShunt group was matched with the trabeculectomy group for age, known duration of disease, and number and classes of intraocular pressure (IOP) lowering medications to have similar conjunctival conditions. The study is part of the Dresden Glaucoma and Treatment Study, using a uniform study design, with the same inclusion and exclusion criteria, follow-ups and standardized definitions of success and failure for both procedures.

PRIMARY OUTCOME MEASURES

mean diurnal IOP (mdIOP, mean of 6 measurements), peak IOP, and IOP fluctuations.

SECONDARY OUTCOME MEASURES

success rates, number of IOP lowering medications, visual acuity, visual fields, complications, surgical interventions, and adverse events.

RESULTS

Sixty eyes of 60 patients, 30 in each group, were analyzed after 1-year follow-ups. Median [Q25, Q75] mdIOP (mmHg) dropped from 16.2 [13.8-21.5] to 10.5 [8.9-13.5] in the MicroShunt and from 17.6 [15.6-24.0] to 11.1 [9.5-12.3] in the trabeculectomy group, both without glaucoma medications. Reduction of mdIOP (P = .596), peak IOP (P = .702), and IOP fluctuations (P = .528) was not statistically significantly different between groups. The rate of interventions was statistically significantly higher in the trabeculectomy group, especially in the early postoperative period (P = .018). None of the patients experienced severe adverse events.

CONCLUSION

Both procedures are equally effective and safe in lowering mdIOP, peak IOP and IOP fluctuations in patients with POAG, one year after surgery.

CLINICAL TRIAL REGISTRATION

NCT02959242.

Outcomes of Open Bleb Revision After PreserFlo MicroShunt Failure in Patients With Glaucoma

PRCIS

After the open bleb revision following PreserFlo, the mean postoperative intraocular pressure (IOP) was lowered from 26.4 ± 9.9 mm Hg to 12.9 ± 5.6 mm Hg at 1 month and 15.9 ± 4.1 mm Hg at 12 months.

PURPOSE

The purpose of this study was to evaluate the effectiveness and safety of an open bleb revision with mitomycin- C (MMC) for bleb fibrosis after PreserFlo MicroShunt implantation.

PATIENTS AND METHODS

We performed a retrospective analysis of 27 consecutive patients with bleb fibrosis after PreserFlo MicroShunt Implantation that underwent an open revision with MMC 0.2 mg/mL applied for 3 minutes at the Department of Ophthalmology of the Mainz, University Medical Center, Mainz, Germany. Demographic data, such as age, sex, glaucoma type, number of glaucoma medications, IOP before and after PreserFlo implantation and revision, complications, and reoperations within 12 months, were analyzed.

RESULTS

Twenty-seven patients (27 eyes) received an open revision after previous PreserFlo Microshunt implantation and consecutive bleb fibrosis. The mean preoperative IOP was 26.4 ± 9.9 mm Hg before revision, 7.0 ± 2.7 mm Hg ( P < 0.001) in the first week after the revision, and 15.9 ± 4.1 mm Hg at 12 months ( P = 0.02). Four patients needed IOP-lowering medication after 12 months. One patient had a positive Seidel test and needed a conjunctival suture. Four patients required a second procedure due to recurring bleb fibrosis.

CONCLUSIONS

At 12 months, open revision with MMC for bleb fibrosis after failed PreserFlo implantation effectively and safely reduced IOP with a similar medication burden.

Will the PRESERFLO™ MicroShunt impact the future of trabeculectomy practice? A UK and Éire Glaucoma Society National Survey

BACKGROUND/OBJECTIVES

To explore the attitudes of UK glaucoma specialists regarding the current and future practice of trabeculectomy and the novel PRESERFLO™ MicroShunt (PF-MS) device, and intentions to adopt the PF-MS into routine glaucoma surgical practice.

METHODS

Online survey of UK and Éire Glaucoma Society members.

RESULTS

43 glaucoma consultants completed the survey. All surgeons performed trabeculectomies (median of 40 annually) and 51% undertook PF-MS procedures (median of 22.5 annually). The mean duration of surgery was reported as 48.9 (SD 13.3) and 31.2 (SD 9.9) min for trabeculectomy and PF-MS respectively (p < 0.0001). For surgeons not currently using the PF-MS, 65% planned to do so. Respondents judged completion of 35 trabeculectomies and 10 PF-MS were required to achieve basic competence. 91% of participants predicted their trabeculectomy volume would decrease and 73% expected PF-MS usage to increase. Respondents reported a median of six and four follow-ups within 3 months post surgery for trabeculectomy and PF-MS respectively (p < 0.0001). Respondents reported trabeculectomy required more post-operative interventions than the PF-MS and 81.8% judged the patient experience to be better with the PF-MS. The PF-MS was deemed suitable for early visual field loss by 72% of respondents, severe visual field loss by 35% and normal tension glaucoma by 21%.

CONCLUSION

The PF-MS has seen rapid adoption in the UK. Respondents predict its usage will significantly increase whilst trabeculectomies will decrease. They report the PF-MS is quicker to learn and perform, and requires less post-operative follow-ups and interventions which may facilitate a more efficient service delivery for patients requiring glaucoma surgery.

PreserFlo™ MicroShunt Versus Ab Externo Canaloplasty in Patients With Moderate to Advanced Open-Angle Glaucoma: 12-Month Follow-Up of a Single-Center Retrospective Study

Purpose To evaluate and compare the efficacy and safety of the PreserFlo MicoShunt and the canaloplasty in patients with moderate to advanced glaucoma. Methods In this retrospective study, 300 patients with moderate to advanced glaucoma underwent either the implantation of the PreserFlo™ MicroShunt (group A) or a canaloplasty (group B). All patients underwent regular follow-up examinations in our department every two days, every two weeks, and every three, six, and 12 months postoperatively. Examinations included measurement of the best corrected visual acuity (BCVA), slit-lamp biomicroscopy of the anterior and posterior segments, intraocular pressure (IOP) measurement using Goldmann applanation tonometry, visual field perimetry, and measurement of the endothelial cell density (ECD). Efficacy was shown by the absolute and qualified success rates calculated with the Kaplan-Meyer analysis. Results  In group A, IOP was significantly reduced at 12 months (13.37 ± 3.94 mmHg, p≤ 0.01) postoperatively in comparison to baseline (23.47 ± 8.39 mmHg). In group B, there was also a reduction in IOP at 12 months (14.32 ± 3.59 mmHg, p≤ 0.01) in comparison to the baseline (18.86 ± 5.82 mmHg). Comparing both groups, the IOP of patients who received the PreserFlo™ MicroShunt was significantly lower than the IOP of patients receiving canaloplasty after 12 months (p=0.049). Patients in both groups were treated with significantly fewer topical agents after 12 months (group A: baseline = 2.53±1.56; 12 months: 0.43 ± 0.83, p≤0.01; group B: baseline 2.62 ± 0.87; 12 months: 1.52 ± 0.99, p≤0.01). Patients receiving the PreserFlo™ MicroShunt applied significantly fewer topical agents than patients who underwent canaloplasty (p≤ 0.01). One year after surgery, the cumulative probability of absolute success was 81.33% in group A and 14.67% in group B. After one year, the cumulative probability of qualified success was 93.33% in group A and 82.00% in group B. Conclusion The PreserFlo™ as well as the canaloplasty offer many advantages and only a few disadvantages for patients with glaucoma. However, the respective patient's history and individual risk profile play an important role in the decision of the glaucoma specialist regarding the most appropriate surgical treatment for each patient. Patients with a high risk of conjunctival scarring and postoperative complications may benefit more from a canaloplasty, whereas patients who need a lower average IOP and show intolerance to any topical agents may require the PreserFlo™ implantation.