Efficacy and Safety of the Preserflo Microshunt With Mitomycin C for the Treatment of Open Angle Glaucoma

Abstract

Précis: The Preserflo Microshunt (PSM) is a safe and effective glaucoma microfiltering implant that significantly reduces the intraocular pressure (IOP), either alone or in combination with phacoemulsification, during the first year after surgery. Purpose:The purpose of this study was to assess the safety and efficacy of the PSM for the treatment of open angle glaucoma with 0.2 mg/mL mitomycin C, either alone or in combination with cataract surgery. Methods:A retrospective, open-label study of 64 eyes with primary open angle glaucoma that underwent PSM implantation and were followed up for at least 9 months. Success was defined as IOP 6-17 mm Hg and a reduction of at least 20%, complete without hypotensive medication, and qualified with medication. Safety was assessed by the incidence of adverse events. Secondary endpoints included mean hypotensive medications, visual acuity, and incidence of needling and surgical revision.Results: A total of 51 eyes underwent PSM alone and 13 underwent PSM+phacoemulsification. In the overall population of the study, the mean IOP was significantly reduced from 22.03 ± 0.7 mm Hg at baseline to 12.7 ± 0.4 mm Hg at the final visit, P < 0.0001 (mean follow-up: 11 ± 1.4 mo). The IOP was significantly reduced in both groups (P < 0.0001). Ocular hypotensive medication was reduced significantly from 2.7 ± 0.7 to 0.2 ± 0.5 (P < 0.0001). No significant differences were found in IOP-lowering medication between groups (PSM alone, 0.2 ± 0.08; PSM+phacoemulsification, 0.1 ± 0.1; P = 0.2). At the final visit, 70.3% were considered as complete success and 12.5% as qualified success. The most common adverse event was clinical hypotony (7.8%) followed by hyphema (4.7%), and anterior chamber reformation (1.6%). Overall, 1.6% required needling and 15.6% surgical revision to restore the flow. Conclusion:Glaucoma surgery with the PSM and mitomycin C was efficacious and safe in the short term, either alone or in combination with cataract surgery, and may be considered a surgical option for lowering IOP in primary open angle glaucoma.

Efficacy of the PRESERFLO MicroShunt and a Meta-Analysis of the Literature

“…The literature search yielded a total of 311 articles of which 14 studies (including 1213 PRESERFLO MicroShunt surgeries) were included in the current study and considered eligible for the meta-analysis ( Table S1, Figure S2 ) [ 9 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 27 , 28 , 29 , 30 ]. Follow-up ranged from 12 months to 72 months.…”

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

“…Given that the most commonly observed bleb after PreserFlo Microshunt implantation is localized beneath Tenon’s capsule posterior to the limbus, as reported by Ibarz Barberá et al 23 in 2022, and considering the deep positioning of the device, an open revision seems to be a suitable approach 22 . It allows the removal of scar tissue surrounding the tube, which is usually responsible for stopping the flow 1 …”

“…Similar, newer surgical procedures, such as PreserFlo Microshunt implantation, have also demonstrated a notable percentage of bleb fibrosis, often necessitating additional surgical interventions. Bleb fibrosis occurs among 3.4% after 3 months, 15.6% after 9 months, 19.0% after 12 months, and up to 53% after 4 years after PreserFlo Microshunt implantation 1,7,18–21 . Up to now, there is no recommended surgical procedure in case of bleb fibrosis for PreserFlo Microshunt implantation due to the lack of data.…”

“…Previous research has demonstrated that the usage of antimetabolites reduces the risk of bleb failure after trabeculectomy, 27–30 MMC is also used during the initial PreserFlo implantation. However, Ibarz Barbera et al 1 discussed that there is maybe a need for additional investigation on whether MMC is needed in the mid-posterior region of the eye where the PreserFlo Microshunt drains and the Tenon capsule is thicker. In this area, a larger amount of fibroblasts is residing.…”

Wound Healing Response After Bleb-Forming Glaucoma Surgery With a SIBS Microshunt in Rabbits

“… 11 Clinical studies have shown that the overall success rate of the PreserFlo MicroShunt is 70% after approximately 1 year. 12 , 13 Although effective in reducing IOP, surgeries may still fail due to the formation of fibrosis, even with the additional usage of MMC. 14 , 15 Patients will often require additional IOP-lowering medications or surgeries to reach the desired low IOP level.…”