Therapeutic Success and Revision Rate after Preserflo MicroShunt Implantation: A Monocentric Analysis of 74 Cases

BACKGROUND: Filtrating surgeries have been the gold standard in glaucoma surgery for decades, yet fibrotic processes remain a major cause of therapeutic failure. Modern glaucoma surgeries aim to offer a less invasive alternative but are often less effective in reducing intraocular pressure (IOP). The Preserflo MicroShunt combines the principles of traditional filtering surgery with minimally invasive techniques to achieve an effective IOP reduction.

PATIENTS AND METHODS: This retrospective, single-centre study analysed the clinical data of 74 patients who underwent Preserflo MicroShunt implantation in a university eye clinic between 2021 and 2022. The mean age was 71.1 ± 10.3 years. The most common glaucoma types were primary open-angle glaucoma (52.7%), pseudoexfoliation glaucoma (22.9%), normal-tension glaucoma (9.4%), and angle-closure glaucoma (4%). The median follow-up time was 326 days. Treatment success was evaluated based on IOP, revision rates, and the necessity of additional pressure-lowering interventions using descriptive statistics and Kaplan-Meier analysis.

RESULTS: After approximately 1 year (326 days), 38.0% achieved absolute success (IOP ≤ 18 mmHg and ≥20% reduction from baseline without additional medication), while 39.9% achieved relative success (IOP ≤ 18 mmHg and ≥20% reduction, including topical medication). No further IOP-lowering interventions were required in 78.7% of cases, and 63.8% of patients did not require a revision of the Preserflo implant.

CONCLUSION: This monocentric study presents current, consistent data from our clinic on the efficacy of the Preserflo MicroShunt in glaucoma patients, thereby complementing existing evidence on comparable filtering procedures. The observed success rates were slightly lower than those reported for other procedures, possibly due to the tertiary referral setting, complex pre-treatment histories, and the retrospective study design with non-standardized follow-up intervals and decreasing long-term risk populations. Longer prospective studies are needed to assess long-term efficacy and safety outcomes.