Evaluation of the Ultrastructural and In Vitro Flow Properties of the PRESERFLO MicroShunt

Barberá, Marta Ibarz; Hernández-Verdejo, José Luis; Bragard, J.; Burguete, Javier; Fernández, Luis García; Rivero, Pedro Taña; Liaño, Rosario Gómez de; Teus, Miguel A.

doi:10.1167/tvst.10.13.26

Cited by 17 publications

(24 citation statements)

References 34 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compared with its main competitor, XEN45 (XEN-GGM; Allergan Plc, Parsippany, NJ, EEUU), most studies have reported hypotony rates comparable to PSM (Table 7), despite resistance to flow is 3.4-fold higher through XEN45. 23 Interestingly, in the study conducted by Kim et al, 29 63.2%-83.3% of the patients experienced hypotony, probably due to the high concentration of injected MMC used in the study (70% of the patients received an injection of 0.4 mg/mL without wash-out during an "ab interno"-closed conjunctiva technique). Regarding other filtering surgeries, Tables 8 and 9 show the hypotony rates reported by some studies about trabeculectomy, Express (Alcon, Fort Worth, TX, EEUU) and glaucoma drainage devices.…”

Section: Discussionmentioning

confidence: 83%

“…5 The review conducted by Bell et al 22 concluded that with PSM, the trend is to achieve higher rates of success with higher concentrations of MMC, increasing the rate of device-related AEs and reoperations as well. The clinical study with the longest follow-up has been carried out by Batlle et al, 9 reporting the outcomes of 23 patients with primary open angle glaucoma (POAG) 5 years after surgery using 0.4 mg/mL MMC for 3 minutes. The authors concluded that the reduction of the mean IOP and the number of hypotensive medications on the long term after DOI: 10.1097/IJG.0000000000002052 PSM implantation was sustained over time, with a low rate of postoperative complications and no long-term sight-threatening AEs.…”

mentioning

confidence: 99%

See 1 more Smart Citation

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

Barberá¹,

Galdón²,

Magro³

et al. 2022

Journal of Glaucoma

View full text Add to dashboard Cite

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.

show abstract

Section: Discussionmentioning

confidence: 83%

mentioning

confidence: 99%

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

Barberá¹,

Galdón²,

Magro³

et al. 2022

Journal of Glaucoma

View full text Add to dashboard Cite

show abstract

“…Although the effect of the 10.0 nylon stent for outflow restriction as a treatment for postoperative prolonged hypotony was previously described [ 23 ], this is the first study to investigate the efficacy of PMS flow restriction in high-risk myopic eyes and its preventive effect on the early hypotony rate. In vitro studies proved that the PMS does not offer hydraulic resistance to outflow similarly to other non-valved shunts, for example, Molteno and Baerveldt [ 24 , 25 , 26 ]; therefore, the only opposition to excessive outflow is the filtration bleb pressure, which, in the early postoperative period, is minimal due to the absence of conjunctival and Tenon fibrosis [ 25 ]. It follows that a major problem of non-valved, bleb-forming, shunt implantation is the early outflow control [ 8 , 9 , 10 , 11 , 24 , 27 , 28 ], and early hypotony is a relatively frequent complication compared to late hypotony, which occurs more rarely.…”

Section: Discussionmentioning

confidence: 99%

Systematic Preserflo MicroShunt Intraluminal Stenting for Hypotony Prevention in Highly Myopic Patients: A Comparative Study

Lupardi

Laffi

Moramarco

et al. 2023

JCM

View full text Add to dashboard Cite

Transient hypotony is the most common early complication after Preserflo MicroShunt (PMS) implantation. High myopia is a risk factor for the development of postoperative hypotony-related complications; therefore, it is advisable that PMS implantation in patients should be performed while employing hypotony preventive measures. The aim of this study is to compare the frequency of postoperative hypotony and hypotony-related complications in high-risk myopic patients after PMS implantation with and without intraluminal 10.0 nylon suture stenting. This is a retrospective, case–control, comparative study of 42 eyes with primary open-angle glaucoma (POAG) and severe myopia that underwent PMS implantation. A total of 21 eyes underwent a non-stented PMS implantation (nsPMS), while in the remaining eyes (21 eyes), PMS was implanted with an intraluminal suture (isPMS group). Hypotony occurred in six (28.57%) eyes in the nsPMS group and none in the isPMS group. Choroidal detachment occurred in three eyes in the nsPMS group; two of them were associated with the shallow anterior chamber and one was associated with macular folds. At 6 months after surgery, the mean IOP was 12.1 ± 3.16 mmHg and 13.43 ± 5.22 mmHg (p = 0.41) in the nsPMS and isPMS group, respectively. PMS intraluminal stenting is an effective measure to prevent early postoperative hypotony in POAG highly myopic patients.

show abstract

“…One reason behind this is that such devices are totally passive, i.e., the drainage of aqueous humor depends upon a fixed hydrodynamic resistance of the shunt [16]. In many cases, however, the hydrodynamic resistance of the shunt may not be optimal which may lead to high IOP, when the resistance in the subconjunctival space is too high (due to the presence of a scar layer), or to overdrainage, if the resistance is too low (resulting in hypotony) [17]. To determine the ideal hydrodynamic resistance that a glaucoma implant must have to overcome these two most common postoperative complications-bleb scarring and hypotony-we developed a model that calculates the pressure in the bleb under these conditions.…”

Section: Plos Onementioning

confidence: 99%

A model for designing intraocular pressure-regulating glaucoma implants

et al. 2022

View full text Add to dashboard Cite

Glaucoma is a group of eye conditions that damage the optic nerve, the health of which is vital for vision. The key risk factor for the development and progression of this disease is increased intraocular pressure (IOP). Implantable glaucoma drainage devices have been developed to divert aqueous humor from the glaucomatous eye as a means of reducing IOP. The artificial drainage pathway created by these devices drives the fluid into a filtering bleb. The long-term success of filtration surgery is dictated by the proper functioning of the bleb and overlying Tenon’s and conjunctival tissue. To better understand the influence of the health condition of these tissues on IOP, we have developed a mathematical model of fluid production in the eye, its removal from the anterior chamber by a particular glaucoma implant–the PRESERFLO® MicroShunt–, drainage into the bleb and absorption by the subconjunctival vasculature. The mathematical model was numerically solved by commercial FEM package COMSOL. Our numerical results of IOP for different postoperative conditions are consistent with the available evidence on IOP outcomes after the implantation of this device. To obtain insight into the adjustments in the implant’s hydrodynamic resistance that are required for IOP control when hypotony or bleb scarring due to tissue fibrosis take place, we have simulated the flow through a microshunt with an adjustable lumen diameter. Our findings show that increasing the hydrodynamic resistance of the microshunt by reducing the lumen diameter, can effectively help to prevent hypotony. However, decreasing the hydrodynamic resistance of the implant will not sufficiently decrease the IOP to acceptable levels when the bleb is encapsulated due to tissue fibrosis. Therefore, to effectively reduce IOP, the adjustable glaucoma implant should be combined with a means of reducing fibrosis. The results reported herein may provide guidelines to support the design of future glaucoma implants with adjustable hydrodynamic resistances.

show abstract

Evaluation of the Ultrastructural and In Vitro Flow Properties of the PRESERFLO MicroShunt

Cited by 17 publications

References 34 publications

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

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

Systematic Preserflo MicroShunt Intraluminal Stenting for Hypotony Prevention in Highly Myopic Patients: A Comparative Study

A model for designing intraocular pressure-regulating glaucoma implants

Contact Info

Product

Resources

About