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Neubauer J, Suesskind D, Gassel CJ, Nasyrov E, Voykov B. Histopathological findings of failed blebs after microinvasive bleb surgery with the XEN Gel Stent and Preserflo MicroShunt. Graefes Arch Clin Exp Ophthalmol 2024:10.1007/s00417-024-06479-w. [PMID: 38625448 DOI: 10.1007/s00417-024-06479-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 03/27/2024] [Accepted: 03/28/2024] [Indexed: 04/17/2024] Open
Abstract
PURPOSE The success of XEN Gel Stent (XEN) and Preserflo MicroShunt (Preserflo) implantation depends mainly on the development of bleb fibrosis. This study aimed to describe the histological findings of bleb fibrosis after XEN and Preserflo surgery. METHODS This retrospective study included patients with different types of glaucoma who underwent revision surgery after XEN or Preserflo implantation. The available clinical information and histological samples of removed fibrotic tissue were analyzed. RESULTS Thirty-six patients were included. Revision surgery was performed at a median of 195 (range = 31-1264) days after primary surgery. The mean intraocular pressure changed from 29.1 (± 10.3) mmHg at baseline to 18.3 (± 8.7) mmHg (- 37%; p < 0.0001) and 16.2 (± 4.2) mmHg (- 45%; p < 0.0001) after 6 and 12 months, respectively. Histological analysis revealed an increase in activated fibroblasts and macrophages in all specimens and a parallel orientation of fibroblasts in a minor part of the probe in 60% of the specimens. No pronounced inflammatory reaction in the form of lymphocytic or granulocytic infiltration was observed. The comparison of specimens from uveitic glaucoma and primary open-angle glaucoma patients revealed no significant differences. CONCLUSIONS The histological analysis of fibrotic blebs from the XEN and Preserflo implants did not show any pronounced immune or foreign-body reaction and revealed a similar histological pattern of failed blebs after trabeculectomy.
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Affiliation(s)
- Jonas Neubauer
- Department of Ophthalmology, University Eye Hospital, Eberhard Karls University, Elfriede-Aulhorn Str. 7, 72076, Tübingen, Germany.
| | - Daniela Suesskind
- Department of Ophthalmology, University Eye Hospital, Eberhard Karls University, Elfriede-Aulhorn Str. 7, 72076, Tübingen, Germany
| | - Caroline J Gassel
- Department of Ophthalmology, University Eye Hospital, Eberhard Karls University, Elfriede-Aulhorn Str. 7, 72076, Tübingen, Germany
| | - Emil Nasyrov
- Department of Ophthalmology, University Eye Hospital, Eberhard Karls University, Elfriede-Aulhorn Str. 7, 72076, Tübingen, Germany
| | - Bogomil Voykov
- Department of Ophthalmology, University Eye Hospital, Eberhard Karls University, Elfriede-Aulhorn Str. 7, 72076, Tübingen, Germany
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Gniesmer S, Sonntag SR, Gapeeva A, Cojocaru A, Kaps S, Adelung R, Sewing J, Tura A, Grisanti S, Grisanti S. In vivo evaluation of a nanotechnology-based microshunt for filtering glaucoma surgery. Sci Rep 2024; 14:4452. [PMID: 38396005 PMCID: PMC10891163 DOI: 10.1038/s41598-024-54960-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Accepted: 02/19/2024] [Indexed: 02/25/2024] Open
Abstract
To carry out the preclinical and histological evaluation of a novel nanotechnology-based microshunt for drainage glaucoma surgery. Twelve New Zealand White rabbits were implanted with a novel microshunt and followed up for 6 weeks. The new material composite consists of the silicone polydimethylsiloxane (PDMS) and tetrapodal Zinc Oxide (ZnO-T) nano-/microparticles. The microshunts were inserted ab externo to connect the subconjunctival space with the anterior chamber. Animals were euthanized after 2 and 6 weeks for histological evaluation. Ocular health and implant position were assessed at postoperative days 1, 3, 7 and twice a week thereafter by slit lamp biomicroscopy. Intraocular pressure (IOP) was measured using rebound tonometry. A good tolerability was observed in both short- and medium-term follow-up. Intraocular pressure was reduced following surgery but increased to preoperative levels after 2 weeks. No clinical or histological signs of inflammatory or toxic reactions were seen; the fibrotic encapsulation was barely noticeable after two weeks and very mild after six weeks. The new material composite PDMS/ZnO-T is well tolerated and the associated foreign body fibrotic reaction quite mild. The new microshunt reduces the IOP for 2 weeks. Further research will elucidate a tube-like shape to improve and prolong outflow performance and longer follow-up to exclude medium-term adverse effects.
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Affiliation(s)
- Stefanie Gniesmer
- Department of Ophthalmology, University of Luebeck, Luebeck, Germany.
| | | | - Anna Gapeeva
- Institute for Materials Science, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Ala Cojocaru
- Institute for Materials Science, Christian-Albrechts-University of Kiel, Kiel, Germany
- Phi-Stone AG, Kiel, Germany
| | - Sören Kaps
- Institute for Materials Science, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Rainer Adelung
- Institute for Materials Science, Christian-Albrechts-University of Kiel, Kiel, Germany
| | - Judith Sewing
- Department of Ophthalmology, University of Luebeck, Luebeck, Germany
| | - Aysegül Tura
- Department of Ophthalmology, University of Luebeck, Luebeck, Germany
| | | | - Swaantje Grisanti
- Department of Ophthalmology, University of Luebeck, Luebeck, Germany
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Schneider S, Kallab M, Murauer O, Reisinger AS, Strohmaier S, Huang AS, Bolz M, Strohmaier CA. Bleb vessel density as a predictive factor for surgical revisions after Preserflo Microshunt implantation. Acta Ophthalmol 2024. [PMID: 38306110 DOI: 10.1111/aos.16642] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2023] [Revised: 12/20/2023] [Accepted: 01/15/2024] [Indexed: 02/03/2024]
Abstract
PURPOSE Bleb failure is a common complication after glaucoma filtration surgery. Different bleb classification schemes incorporating filtration bleb vascularization have been proposed, but the reported correlation with intraocular pressure (IOP) has been variable, possibly because of subjective vascularization grading. The purpose of the present study was to evaluate bleb vascularization after Preserflo Microshunt (PM) implantation using anterior segment OCT-angiography (AS-OCTA) as a biomarker for bleb failure. METHODS Twenty-three eyes of twenty-three patients underwent PM implantation. Up to 12 months after surgery PM scleral passage-centred AS-OCTA measurements (PLEX Elite 9000) for bleb-vessel density (BVD) determination were performed and IOP as well as necessity for surgical revisions (needling and open revision) were documented. After multi-step image analysis (region of interest definition, artefact removal, binarization, BVD calculation), the predictive value of early postoperative BVD for surgical revisions was assessed using logistic regression modelling. RESULTS Baseline IOP (23.57 ± 7.75 mmHg) decreased significantly to 8.30 ± 2.12, 9.17 ± 2.33 and 11.70 ± 4.40 mmHg after 1, 2 and 4 week(s), and 13.48 ± 5.83, 11.87 ± 4.49, 12.30 ± 6.65, 11.87 ± 3.11 and 13.05 ± 4.12 mmHg after 2, 3, 6, 9 and 12 month(s), respectively (p < 0.001). Nine patients (39%) needed surgical revisions after a median time of 2 months. Bleb vessel densities at 2 and 4 weeks were significantly associated with future surgical revisions upon logistic regression analysis (2 W/4 W likelihood-ratio test p-value: 0.0244/0.0098; 2 W/4 W area under the receiver operating characteristics curve: 0.796/0.909). CONCLUSION Filtration bleb vessel density can be determined using AS-OCTA in the early postoperative period and is predictive for bleb failure after PM implantation.
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Affiliation(s)
- Sophie Schneider
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Martin Kallab
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Olivia Murauer
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Anna-Sophie Reisinger
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Susanne Strohmaier
- Department of Epidemiology, Center for Public Health, Medical University of Vienna, Vienna, Austria
| | - Alex S Huang
- Hamilton Glaucoma Center, The Viterbi Family Department of Ophthalmology, Shiley Eye Institute, University of California, San Diego, California, USA
| | - Matthias Bolz
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
| | - Clemens A Strohmaier
- Department of Ophthalmology and Optometry, Kepler University Hospital, Johannes Kepler University, Linz, Austria
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Fang Z, Bi S, Brown JD, Chen J, Pan T. Microfluidics in the eye: a review of glaucoma implants from an engineering perspective. Lab Chip 2023; 23:4736-4772. [PMID: 37847237 DOI: 10.1039/d3lc00407d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2023]
Abstract
Glaucoma is a progressive optic neuropathy in the eye, which is a leading cause of irreversible blindness worldwide and currently affects over 70 million individuals. Clinically, intraocular pressure (IOP) reduction is the only proven treatment to halt the progression of glaucoma. Microfluidic devices such as glaucoma drainage devices (GDDs) and minimally invasive glaucoma surgery (MIGS) devices are routinely used by ophthalmologists to manage elevated IOP, by creating an artificial pathway for the over-accumulated aqueous humor (AH) in a glaucomatous eye, when the natural pathways are severely blocked. Herein, a detailed modelling and analysis of both the natural microfluidic pathways of the AH in the eye and artificial microfluidic pathways formed additionally by the various glaucoma implants are conducted to provide an insight into the causes of the IOP abnormality and the improvement schemes of current implant designs. The mechanisms of representative glaucoma implants have been critically reviewed from the perspective of microfluidics, and we have categorized the current implants into four groups according to the targeted drainage sites of the AH, namely Schlemm's canal, suprachoroidal space, subconjunctival space, and ocular surface. In addition, we propose to divide the development and evolution of glaucoma implant designs into three technological waves, which include microtube (1st), microvalve (2nd) and microsystem (3rd). With the emerging trends of minimal invasiveness and artificial intelligence in the development of medical implants, we envision that a comprehensive glaucoma treatment microsystem is on the horizon, which is featured with active and wireless control of IOP, real-time continuous monitoring of IOP and aqueous rate, etc. The current review could potentially cast light on the unmatched needs, challenges, and future directions of the microfluidic structural and functional designs of glaucoma implants, which would enable an enhanced safety profile, reduced complications, increased efficacy of lowering IOP and reduced IOP fluctuations, closed-loop and on-demand control of IOP, etc.
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Affiliation(s)
- Zecong Fang
- Bionic Sensing and Intelligence Center (BSIC), Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China.
| | - Shuzhen Bi
- Center for Intelligent Medical Equipment and Devices (iMED), University of Science and Technology of China, Suzhou, Jiangsu, 215123, China
| | | | - Junyi Chen
- Department of Ophthalmology and Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, 200031, China
- NHC Key Laboratory of Myopia, Chinese Academy of Medical Sciences, and Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University), Shanghai, 200031, China
| | - Tingrui Pan
- Bionic Sensing and Intelligence Center (BSIC), Institute of Biomedical and Health Engineering, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, Guangdong, 518055, China.
- Center for Intelligent Medical Equipment and Devices (iMED), University of Science and Technology of China, Suzhou, Jiangsu, 215123, China
- Department of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui, 230026, China
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Jamke M, Herber R, Haase MA, Jasper CS, Pillunat LE, Pillunat KR. PRESERFLO ™ MicroShunt versus trabeculectomy: 1-year results on efficacy and safety. Graefes Arch Clin Exp Ophthalmol 2023; 261:2901-2915. [PMID: 37133501 PMCID: PMC10155172 DOI: 10.1007/s00417-023-06075-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Revised: 04/04/2023] [Accepted: 04/15/2023] [Indexed: 05/04/2023] Open
Abstract
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.
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Affiliation(s)
- Melanie Jamke
- Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany
| | - Robert Herber
- Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany
| | - Maike A Haase
- Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany
| | - Carolin S Jasper
- Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany
| | - Lutz E Pillunat
- Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany
| | - Karin R Pillunat
- Universitätsklinikum Carl Gustav Carus an der Technischen Universität Dresden, Fetscherstrasse 74, 01307, Dresden, Germany.
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Nobl M, Freissinger S, Rudolph K, Vounotrypidis E, Kassumeh S, Priglinger S, Mackert MJ. Long-term Outcomes of PreserFlo MicroShunt versus XEN45 Gel Stent in Open-Angle Glaucoma. Klin Monbl Augenheilkd 2023. [PMID: 37673088 DOI: 10.1055/a-2152-8455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/08/2023]
Abstract
PURPOSE To compare two glaucoma drainage devices with subconjunctival filtration (MicroShunt and XEN) for open-angle glaucoma (OAG), with respect to effectiveness and safety. PATIENTS AND METHODS This is a single center, retrospective, interventional study. In total, 106 eyes of 95 patients with OAG underwent surgery. Of these patients, 51 eyes of 45 patients received a MicroShunt implantation and 55 eyes of 50 patients received an XEN implantation. Failure was defined as an intraocular pressure (IOP) lower than 5 or higher than 17 mmHg at the end of follow-up after 2 years, the need for surgical revision, secondary glaucoma surgery, or loss of light perception. Outcome was rated as complete success or qualified success, depending on whether it was achieved with or without anti-glaucomatous medications. Postoperative complications and interventions were also documented for both groups. RESULTS In the MicroShunt group, mean IOP decreased from 20.6 ± 7.5 mmHg at baseline to 13.0 ± 3.9 mmHg (p < 0.0001) after 2 years. In the XEN group, mean IOP was lowered from 22.5 ± 7.9 mmHg to 13.5 ± 4.2 mmHg (p < 0.0001). In both groups, the mean number of medications was significantly reduced (MicroShunt 2.7 ± 1.2 to 0.9 ± 2.5; p < 0.0001 vs. XEN 3.2 ± 0.9 to 1.1 ± 1.5; p < 0.0001). In regard to success rates, 37% of MicroShunt patients achieved complete success and 57% qualified success at the end of follow-up. In the XEN group, rates were 25 and 45%, respectively. Patient demographics differed between the two groups with respect to age (MicroShunt 72.8 ± 8.7 vs. XEN 67.7 ± 9.0 years; p = 0.002). Postoperative complications were comparable between the two groups. CONCLUSION Both MicroShunt and XEN are effective in significantly reducing IOP and glaucoma medications in OAG, and with a good safety profile.
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Affiliation(s)
- Matthias Nobl
- Department of Ophthalmology, University Hospital of Munich, Munich, Germany
| | | | - Katrin Rudolph
- Department of Ophthalmology, University Hospital of Munich, Munich, Germany
| | | | - Stefan Kassumeh
- Department of Ophthalmology, University Hospital of Munich, Munich, Germany
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Lüke JN, Reinking N, Dietlein TS, Haendel A, Enders P, Lappas A. Intraoperative primary partial occlusion of the PreserFlo MicroShunt to prevent initial postoperative hypotony. Int Ophthalmol 2023; 43:2643-2651. [PMID: 36905460 PMCID: PMC10371896 DOI: 10.1007/s10792-023-02664-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 02/19/2023] [Indexed: 03/12/2023]
Abstract
PURPOSE The aim of the underlying study was to present a new surgical method in PreserFlo MicroShunt surgery for glaucoma. A removable polyamide suture was placed into the lumen of the MicroShunt during implantation to prevent early postoperative hypotony. METHODS Thirty-one patients undergoing stand-alone glaucoma surgery with implantation of a PreserFlo MicroShunt and an intraluminal occlusion were retrospectively reviewed and compared to a control group without occlusion. Inclusion criteria were diagnosis of primary open-angle glaucoma or secondary open-angle glaucoma due to pseudoexfoliation or pigment dispersion. Patients with a history of filtrating glaucoma surgery were excluded. RESULTS IOP decreased from 26.9 ± 6.6 to 18.0 ± 9.5 mmHg at the first postoperative day after PreserFlo MicroShunt implantation. Postoperative removal of the occluding suture resulted in a mean IOP reduction in 11.1 ± 7.6 mmHg. Mean visual acuity was 0.43 ± 0.24 logMAR during the first postoperative examination. The interval with the occluding intraluminal suture in place varied from days to 2-3 weeks. Patients were followed up to 1 year. CONCLUSION Implantation of a PreserFlo MicroShunt combined with an intraluminal suture prevented postoperative hypotony in all patients. Mean postoperative pressure was reduced despite the occluding suture in place.
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Affiliation(s)
- Jan Niklas Lüke
- Department of Ophthalmology, Medical Faculty, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany.
| | - Niklas Reinking
- Department of Ophthalmology, Medical Faculty, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany
| | - Thomas S Dietlein
- Department of Ophthalmology, Medical Faculty, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany
| | - Alexander Haendel
- Department of Ophthalmology, Medical Faculty, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany
| | - Philip Enders
- Department of Ophthalmology, Medical Faculty, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany
| | - Alexandra Lappas
- Department of Ophthalmology, Medical Faculty, University Hospital of Cologne, Kerpener Strasse 62, 50937, Cologne, Germany
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Pereira ICF, van Mechelen RJS, Wyss HM, Pinchuk L, Beckers HJM, den Toonder JMJ. Magnetically actuated glaucoma drainage device for regulating intraocular pressure after implantation. Microsyst Nanoeng 2023; 9:92. [PMID: 37484503 PMCID: PMC10356933 DOI: 10.1038/s41378-023-00561-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/03/2023] [Revised: 05/10/2023] [Accepted: 05/18/2023] [Indexed: 07/25/2023]
Abstract
The key risk factor for glaucoma is increased intraocular pressure (IOP). Glaucoma drainage devices implanted in the eye can reduce IOP and thus stop disease progression. However, most devices currently used in clinical practice are passive and do not allow for postsurgical IOP control, which may result in serious complications such as hypotony (i.e., excessively low IOP). To enable noninvasive IOP control, we demonstrate a novel, miniature glaucoma implant that will enable the repeated adjustment of the hydrodynamic resistance after implantation. This is achieved by integrating a magnetic microvalve containing a micropencil-shaped plug that is moved using an external magnet, thereby opening or closing fluidic channels. The microplug is made from biocompatible poly(styrene-block-isobutylene-block-styrene) (SIBS) containing iron microparticles. The complete implant consists of an SIBS drainage tube and a housing element containing the microvalve and fabricated with hot embossing using femtosecond laser-machined glass molds. Using in vitro and ex vivo microfluidic experiments, we demonstrate that when the microvalve is closed, it can provide sufficient hydrodynamic resistance to overcome hypotony. Valve function is repeatable and stable over time. Due to its small size, our implant is a promising, safe, easy-to-implant, minimally invasive glaucoma surgery device.
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Affiliation(s)
- Inês C. F. Pereira
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
| | - Ralph J. S. van Mechelen
- University Eye Clinic Maastricht, Maastricht University Medical Centre+ (MUMC+), 6202AZ Maastricht, The Netherlands
| | - Hans M. Wyss
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
| | - Leonard Pinchuk
- InnFocus, Inc., a Santen Company, Miami, Florida 33186 USA
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida 33136 USA
| | - Henny J. M. Beckers
- University Eye Clinic Maastricht, Maastricht University Medical Centre+ (MUMC+), 6202AZ Maastricht, The Netherlands
| | - Jaap M. J. den Toonder
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, 5600MB Eindhoven, The Netherlands
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9
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Ahmed IIK, Sadruddin O, Panarelli JF. Subconjunctival filtration in evolution: current evidence on MicroShunt implantation for treating patients with glaucoma. Eye Vis (Lond) 2023; 10:10. [PMID: 36859515 PMCID: PMC9979478 DOI: 10.1186/s40662-022-00322-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 12/06/2022] [Indexed: 03/03/2023]
Abstract
BACKGROUND Although traditional surgical procedures for glaucoma (such as trabeculectomy and tube-shunt implantation) can significantly reduce intraocular pressure (IOP), they are associated with numerous complications, some of which are vision-threatening, or involve prolonged recovery or a highly intensive postoperative course. Micro-invasive glaucoma surgery (MIGS) procedures have shown better safety but reduced efficacy in achieving target IOP. Combinations of these methods have led to the development of subconjunctival micro-invasive procedures with safety comparable to traditional surgery and greater efficacy than minimally invasive methods. This review describes the use of one of these devices, the poly(styrene-block-isobutylene-block-styrene) (SIBS)-based PreserFlo MicroShunt (Santen, Emeryville, CA), in the surgical treatment of patients with glaucoma. MAIN TEXT The MicroShunt is an 8.5-mm tube made of an inert polymer with no endplate, an internal diameter of 70 μm, and fins intended to prevent peritubular flow and anchor the device within the sclera to prevent proximal migration into the eye. Following ab externo implantation, the tube provides a conduit for flow of aqueous humor from the anterior chamber into the subconjunctival/sub-Tenon space. Clinical trials to date have shown that, when paired with mitomycin C (MMC) treatment, MicroShunt implantation significantly reduced both IOP and the number of glaucoma medications. These IOP-lowering results were found both when surgery was performed alone and with phacoemulsification. The MicroShunt also showed a safety profile comparable to that of traditional filtering surgery. CONCLUSIONS The MicroShunt and other novel subconjunctival procedures have shown substantial IOP reductions while mitigating hypotony-related complications. MMC, which modulates fibrosis and scarring postoperatively, is essential to surgical success. Randomized, long-term clinical trials will further clarify the role of controlled micro-incisional device-assisted ab externo glaucoma filtering surgery in long-term glaucoma management.
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Affiliation(s)
- Iqbal Ike K. Ahmed
- grid.223827.e0000 0001 2193 0096John Moran Eye Center, University of Utah, Salt Lake City, UT USA ,grid.17063.330000 0001 2157 2938University of Toronto, Toronto, ON Canada ,grid.477184.9Prism Eye Institute, Mississauga, ON Canada
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10
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Bhayani R, Martínez de la Casa JM, Figus M, Klabe K, Rabiolo A, Mercieca K. Short-term safety and efficacy of Preserflo™ Microshunt in glaucoma patients: a multicentre retrospective cohort study. Eye (Lond) 2023; 37:644-9. [PMID: 35277663 DOI: 10.1038/s41433-022-01995-7] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2021] [Revised: 02/03/2022] [Accepted: 02/16/2022] [Indexed: 11/09/2022] Open
Abstract
BACKGROUND/AIMS To evaluate 1-year success rates and safety profile of Preserflo™ Microshunt in glaucoma patients. METHODS Retrospective multicentre cohort study of 100 consecutive eyes (91 patients) from four tertiary-referral glaucoma centres. Four intraocular pressure (IOP) criteria were defined: A: IOP ≤ 21 mmHg+IOP reduction ≥20% from baseline; B: IOP ≤ 18 mmHg+IOP reduction ≥20%; C: IOP ≤ 15 mmHg+IOP reduction ≥25%; D: IOP≤12 mmHg+IOP reduction ≥30%. Success was defined as qualified or complete based on whether reached with or without medication. Primary outcome was success according to the above criteria. Secondary outcomes included: IOP, best-corrected visual acuity (BCVA), medication use, complications, postoperative interventions, and failure-associated factors. RESULTS Qualified and complete success rates (95% CI) at 12 months were 74%(66-83%) and 58%(49-69%) for criterion A, 72%(63-82%) and 57%(48-68%) for B, 52%(43-63%) and 47%(38-58%) for C, 29%(21-40%) and 26%(19-36%) for D. Overall median (interquartile range (IQR)) preoperative IOP decreased from 21.5(19-28) mmHg to 13(11-16) mmHg at 12 months. BCVA was not significantly different up to 12 months (p = 0.79). Preoperative median (IQR) number of medications decreased from 3 (2-3) to 0 (0-1) at 12 months. Twelve eyes underwent needling, five surgical revision and one device removal due to corneal oedema. There were no hypotony-related complications. Non-Caucasian ethnicity was the only risk factor consistently associated with increased failure. CONCLUSIONS Preserflo™ Microshunt is a viable surgical option in glaucoma patients, with reasonable short-term success rates, decreased medications use, excellent safety profile, smooth postoperative care, and rapid learning curve. Success rates for the most stringent IOP cutoffs were modest, indicating that it may not be the optimal surgery when very low target IOP is required.
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11
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Saeed E, Gołaszewska K, Dmuchowska DA, Zalewska R, Konopińska J. The PreserFlo MicroShunt in the Context of Minimally Invasive Glaucoma Surgery: A Narrative Review. Int J Environ Res Public Health 2023; 20:2904. [PMID: 36833599 PMCID: PMC9957246 DOI: 10.3390/ijerph20042904] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 01/29/2023] [Accepted: 02/01/2023] [Indexed: 05/13/2023]
Abstract
Recently, the quest for novel glaucoma surgical techniques and devices has been underway. Trabeculectomy remains the gold standard, but it requires the implantation of glaucoma drainage devices and frequent follow-ups, and it also carries a high risk of serious complications. The need for less invasive and safer procedures has led to the development of minimally invasive glaucoma surgery (MIGS), particularly for patients with mild-to-moderate disease. Among them, minimally invasive bleb surgery seems to be effective in classical glaucoma surgery, while maintaining MIGS benefits. The relatively new PreserFlo® MicroShunt (Santen, Osaka, Japan) is registered in Europe. It was released in 2019 for the treatment of patients with early-to-advanced open-angle glaucoma, where intraocular pressure (IOP) remains uncontrolled while on maximum tolerated medication and/or where glaucoma progression warrants surgery. This review focuses on the place of the PreserFlo MicroShunt, characterized by ab externo implantation, among MIGS procedures, discussing its advantages and disadvantages. The mechanisms of action, technical aspects, efficacy, and safety issues are summarized. The surgical technique, its efficacy, and safety profile are described, and directions for future studies are indicated. The PreserFlo MicroShunt ensures a high safety profile, minimal anatomical disruption, meaningful IOP-lowering effect, and ease of use for patients and physicians.
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Affiliation(s)
| | | | | | | | - Joanna Konopińska
- Department of Ophthalmology, Medical University of Bialystok, Kilinskiego 1 STR, 15-089 Bialystok, Poland
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12
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Shen R, Li VSW, Wong MOM, Chan PPM. Pediatric Glaucoma-From Screening, Early Detection to Management. Children (Basel) 2023; 10:children10020181. [PMID: 36832310 PMCID: PMC9954748 DOI: 10.3390/children10020181] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/10/2023] [Accepted: 01/16/2023] [Indexed: 01/20/2023]
Abstract
Pediatric glaucoma (PG) covers a rare and heterogeneous group of diseases with variable causes and presentations. Delayed diagnosis of PG could lead to blindness, bringing emotional and psychological burdens to patients' caregivers. Recent genetic studies identified novel causative genes, which may provide new insight into the etiology of PG. More effective screening strategies could be beneficial for timely diagnosis and treatment. New findings on clinical characteristics and the latest examination instruments have provided additional evidence for diagnosing PG. In addition to IOP-lowering therapy, managing concomitant amblyopia and other associated ocular pathologies is essential to achieve a better visual outcome. Surgical treatment is usually required although medication is often used before surgery. These include angle surgeries, filtering surgeries, minimally invasive glaucoma surgeries, cyclophotocoagulation, and deep sclerectomy. Several advanced surgical therapies have been developed to increase success rates and decrease postoperative complications. Here, we review the classification and diagnosis, etiology, screening, clinical characteristics, examinations, and management of PG.
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Affiliation(s)
- Ruyue Shen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
| | - Venice S. W. Li
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Kowloon, Hong Kong, China
| | - Mandy O. M. Wong
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Kowloon, Hong Kong, China
| | - Poemen P. M. Chan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Hong Kong Eye Hospital, Kowloon, Hong Kong, China
- Lam Kin Chung. Jet King-Shing Ho Glaucoma Treatment and Research Centre, Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong, China
- Department of Ophthalmology and Visual Sciences, The Prince of Wales Hospital, Hong Kong, China
- Correspondence: ; Tel.: +852-3943-5807
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13
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Pereira ICF, Wyss HM, Pinchuk L, Beckers HJM, den Toonder JMJ. A model for designing intraocular pressure-regulating glaucoma implants. PLoS One 2022; 17:e0273672. [PMID: 36054120 PMCID: PMC9439203 DOI: 10.1371/journal.pone.0273672] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2022] [Accepted: 08/11/2022] [Indexed: 12/02/2022] Open
Abstract
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.
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Affiliation(s)
- Inês C. F. Pereira
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Hans M. Wyss
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Leonard Pinchuk
- InnFocus, Inc., a Santen Company, Miami, Florida, United States of America
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida, United States of America
| | - Henny J. M. Beckers
- University Eye Clinic Maastricht, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | - Jaap M. J. den Toonder
- Microsystems, Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands
- Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, The Netherlands
- * E-mail:
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14
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van Mechelen RJS, Wolters JEJ, Herfs M, Bertens CJF, Gijbels M, Pinchuk L, Gorgels TGMF, Beckers HJM. Wound Healing Response After Bleb-Forming Glaucoma Surgery With a SIBS Microshunt in Rabbits. Transl Vis Sci Technol 2022; 11:29. [PMID: 36018582 PMCID: PMC9428362 DOI: 10.1167/tvst.11.8.29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The PreserFlo MicroShunt is an innovative implant for the surgical treatment of glaucoma. Although usually effective, surgeries can still fail due to fibrosis. This study was conducted to gain insight into the histological aspects of the fibrotic response and find potential targets to reduce postoperative fibrosis. Methods Fifteen New Zealand White rabbits were implanted with a microshunt and followed up for 40 days. Animals were euthanized at postoperative days (PODs) 1, 5, and 40 to collect eyes for histological evaluation. Bleb formation and ocular health were assessed by slit-lamp (SL) biomicroscopy and optical coherence tomography (OCT). Intraocular pressure (IOP) was measured using rebound tonometry. Results Blebs failed after approximately 2 weeks based on bleb survival and IOP measurements. No severe complications were observed with OCT and SL. Histology revealed a wide variety of cells, in the bleb and around the microshunt, including polymorphonuclear leucocytes (PMNs), myofibroblasts, and foreign body giant cells, at different PODs. Conclusions Implantation of a poly(styrene-b-isobutylene-b-styrene) microshunt in rabbits resulted in the occurrence of a wide variety of cells during the wound-healing response. Future research should further elucidate the potential of these (earlier often overlooked) cells to target the fibrotic response in vivo—for example, by developing novel antifibrotic drugs, methods for sustained delivery of medications, or augmenting material properties. Translational Relevance Current antifibrotic therapies aim to inhibit myofibroblasts; however, a wide variety of cells are involved in the fibrotic response. Future research focusing on these cells could offer novel methods for reducing the fibrotic response after glaucoma surgery.
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Affiliation(s)
- Ralph J S van Mechelen
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands.,Department of Ophthalmology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Chemelot Institute for Science and Technology, Maastricht, the Netherlands
| | - Jarno E J Wolters
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands.,Department of Ophthalmology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Chemelot Institute for Science and Technology, Maastricht, the Netherlands
| | - Marjolein Herfs
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands.,Department of Ophthalmology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Chemelot Institute for Science and Technology, Maastricht, the Netherlands
| | - Christian J F Bertens
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands.,Department of Ophthalmology, School for Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Chemelot Institute for Science and Technology, Maastricht, the Netherlands
| | - Marion Gijbels
- Department of Pathology, Cardiovascular Research Institute Maastricht, School for Oncology and Developmental Biology, Maastricht University, Maastricht, the Netherlands.,Department of Medical Biochemistry, Experimental Vascular Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, the Netherlands
| | | | - Theo G M F Gorgels
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands
| | - Henny J M Beckers
- University Eye Clinic Maastricht, Maastricht University Medical Center+, Maastricht, the Netherlands
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15
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Burgos-Blasco B, García-Feijóo J, Perucho-Gonzalez L, Güemes-Villahoz N, Morales-Fernandez L, Mendez-Hernández CD, Martinez de la Casa JM, Konstas AG. Evaluation of a Novel Αb Εxterno MicroShunt for the Treatment of Glaucoma. Adv Ther 2022; 39:3916-3932. [PMID: 35797002 PMCID: PMC9402735 DOI: 10.1007/s12325-022-02230-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2022] [Accepted: 06/16/2022] [Indexed: 11/29/2022]
Abstract
The surgical management of glaucoma has been revolutionized by the introduction of minimally invasive glaucoma surgery (MIGS). The various MIGS options aim to meaningfully lower intraocular pressure with a better safety profile than traditional glaucoma surgery. The key clinical attributes and the emerging potential of an ab externo MicroShunt (PreserFlo™) are reviewed in the context of published evidence and clinical experience. This novel MicroShunt consists of an 8.5-mm-long tube that is implanted in the eye via an ab externo approach enabling aqueous humor drainage into the sub-Tenon’s space through the formation of a bleb, similar in appearance to that created by trabeculectomy. The efficacy and safety of this procedure, the concomitant use of antimetabolites, the impact of tube positioning, and its future value in clinical practice are critically reviewed. Recent evidence has demonstrated the MicroShunt to be less effective than traditional filtration surgery, but with a significant improvement in safety. Cumulative data suggest that the new implant provides tangible clinical benefits to selected patients with glaucoma in need of further intraocular pressure (IOP) lowering. Future research should delineate the precise role of this and other MIGS options in the rapidly evolving glaucoma treatment algorithm.
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Affiliation(s)
| | - Julián García-Feijóo
- Servicio de Oftalmología, Hospital Clínico San Carlos; IdISSC, Madrid, Spain.,Departamento de Inmunología, Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | | | | | | | - Carmen D Mendez-Hernández
- Servicio de Oftalmología, Hospital Clínico San Carlos; IdISSC, Madrid, Spain.,Departamento de Inmunología, Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Jose M Martinez de la Casa
- Servicio de Oftalmología, Hospital Clínico San Carlos; IdISSC, Madrid, Spain.,Departamento de Inmunología, Oftalmología y ORL, Facultad de Medicina, Universidad Complutense de Madrid, Madrid, Spain
| | - Anastasios G Konstas
- 1st and 3rd University, Departments of Ophthalmology, Aristotle University of Thessaloniki, Thessaloniki, Greece. .,Department of Ophthalmology, 1st University, AHEPA University Hospital, 1 Kyriakidi Street, 54636, Thessaloniki, Greece.
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16
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Nakamura K, Fujimoto T, Okada M, Maki K, Shimazaki A, Kato M, Inoue T. Tissue Reactivity to, and Stability of, Glaucoma Drainage Device Materials Placed Under Rabbit Conjunctiva. Transl Vis Sci Technol 2022; 11:9. [PMID: 35404438 PMCID: PMC9012888 DOI: 10.1167/tvst.11.4.9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To evaluate tissue reactivity to, and the stability of, glaucoma drainage device materials placed under rabbit conjunctiva in vivo. Methods Disks (diameter, 3 mm; thickness, ∼0.3 mm) fabricated from poly(styrene-block-isobutylene-block-styrene) (SIBS), silicone, stainless-steel, or glutaraldehyde cross-linked collagen (GACLC) were inserted under rabbit conjunctiva. Conjunctival and scleral sections obtained at 4, 8, and 12 weeks after surgery were immunostained for α-smooth muscle actin (SMA). The ratio of the maximum thickness of the α-SMA-positive conjunctiva to the scleral thickness (α-SMA/S ratio) was calculated. The in vivo stability of the drainage devices at 12 weeks after insertion was evaluated. Results The mean α-SMA/S ratios of the SIBS and silicone groups were lower than that of the stainless-steel group at 4 weeks after surgery (P < 0.05), and that of the SIBS group was lower than that of the GACLC group (P < 0.05). The ratios at 8 weeks after surgery were lower in the SIBS and silicone groups than in the GACLC group (P < 0.01). The ratios at 12 weeks after surgery were lower in the SIBS and silicone groups than in the GACLC group (P < 0.05). The surface areas of GACLC disks explanted from conjunctivae were significantly lower than that of intact disks (P < 0.01). Conclusions SIBS and silicon were highly biostable and exhibited less tissue reactivity than GACLC in vivo. Translational Relevance Comparisons of materials using animal models can predict the clinical stability and safety of such materials in humans.
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Affiliation(s)
- Kenichi Nakamura
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Tomokazu Fujimoto
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Miho Okada
- Pharmaceutics and Pharmacology Department, Santen Pharmaceutical Co., Ltd., Nara, Japan
| | - Kentaro Maki
- Pharmaceutics and Pharmacology Department, Santen Pharmaceutical Co., Ltd., Nara, Japan
| | - Atsushi Shimazaki
- Pharmaceutics and Pharmacology Department, Santen Pharmaceutical Co., Ltd., Nara, Japan
| | - Masatomo Kato
- Pharmaceutics and Pharmacology Department, Santen Pharmaceutical Co., Ltd., Nara, Japan
| | - Toshihiro Inoue
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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17
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Jabłońska J, Lewczuk K, Konopińska J, Mariak Z, Rękas M. Microinvasive glaucoma surgery: a review and classification of implant-dependent procedures and techniques. Acta Ophthalmol 2022; 100:e327-e338. [PMID: 33988310 PMCID: PMC9291507 DOI: 10.1111/aos.14906] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2020] [Revised: 03/08/2021] [Accepted: 04/22/2021] [Indexed: 12/25/2022]
Abstract
The aim of this article is to discuss how physiology and anatomical background affect the effectiveness of implant‐dependent microinvasive glaucoma surgery (MIGS). First, we provide a micro view of aqueous outflow and tissue behaviour. Second, we review studies exploring the mechanisms of the pressure‐lowering effect of MIGS, as well as tissue behaviour during aqueous flow and tissue motion. We also describe and classify microinvasive surgical procedures and the most important types of implants, as well as their mechanisms of action, implantation techniques and efficacy. Further, we summarize the indications and surgical results presented in recent studies, providing an evidence‐based update on novel and emerging MIGS techniques for the treatment of open‐angle glaucoma. These data can help surgeons to personalize the management of glaucoma and to choose the best MIGS option for individual glaucoma patients.
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Affiliation(s)
- Joanna Jabłońska
- Department of Ophthalmology Military Institute of Medicine Warsaw Poland
| | - Katarzyna Lewczuk
- Department of Ophthalmology Military Institute of Medicine Warsaw Poland
| | - Joanna Konopińska
- Department of Ophthalmology Medical University of Bialystok Białystok Poland
| | - Zofia Mariak
- Department of Ophthalmology Medical University of Bialystok Białystok Poland
| | - Marek Rękas
- Department of Ophthalmology Military Institute of Medicine Warsaw Poland
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18
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Gambini G, Carlà MM, Giannuzzi F, Caporossi T, De Vico U, Savastano A, Baldascino A, Rizzo C, Kilian R, Caporossi A, Rizzo S. PreserFlo® MicroShunt: An Overview of This Minimally Invasive Device for Open-Angle Glaucoma. Vision (Basel) 2022; 6:vision6010012. [PMID: 35225971 PMCID: PMC8883991 DOI: 10.3390/vision6010012] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2021] [Revised: 01/30/2022] [Accepted: 02/03/2022] [Indexed: 01/25/2023] Open
Abstract
For moderate-to-severe glaucoma, trabeculectomy remains the “gold standard” intraocular pressure (IOP)-lowering treatment; nonetheless, this method requires extensive post-operative maintenance. Microinvasive glaucoma surgery (MIGS) treatments are designed to lessen intra- and post-operative care burden while offering an acceptable IOP decrease for individuals with mild to moderate glaucoma. The PreserFlo® MicroShunt (previously InnFocus MicroShunt) is an 8.5 mm glaucoma drainage device manufactured from poly(styrene-block-isobutylene-block-styrene) (SIBS), an extremely biocompatible and bioinert material. The lumen is narrow enough to prevent hypotony, but big enough to avoid being obstructed by sloughed cells or pigment. The device is implanted ab externo, as a stand-alone procedure or in conjunction with cataract surgery, with intraoperative mitomycin C, and a bleb is produced under the conjunctiva and Tenon’s capsule. The MicroShunt was CE-marked in 2012 and designed for primary open-angle glaucoma, the IOP of which remains uncontrolled after maximally tolerated topical treatment. Several clinical trials evaluating the MicroShunt’s long-term safety and effectiveness have been conducted, highlighting the effectiveness of the device over time, along with a tolerable safety profile. The present review aims to gather evidence of PreserFlo’s effectiveness and safety results almost 10 years after its introduction, and furthermore, to compare it with other MIGS and with the gold-standard trabeculectomy for glaucoma management.
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Affiliation(s)
- Gloria Gambini
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
- Correspondence: (G.G.); (M.M.C.); (F.G.); Tel.: +39-3276530138 (M.M.C.)
| | - Matteo Mario Carlà
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
- Correspondence: (G.G.); (M.M.C.); (F.G.); Tel.: +39-3276530138 (M.M.C.)
| | - Federico Giannuzzi
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
- Correspondence: (G.G.); (M.M.C.); (F.G.); Tel.: +39-3276530138 (M.M.C.)
| | - Tomaso Caporossi
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
| | - Umberto De Vico
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
| | - Alfonso Savastano
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
| | - Antonio Baldascino
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
| | - Clara Rizzo
- Ophthalmology, Department of Surgical, Medical and Molecular Pathology and Critical Care Medicine, University of Pisa, 56126 Pisa, Italy;
| | - Raphael Kilian
- Ophthalmology Unit, University of Verona, 37134 Verona, Italy;
| | - Aldo Caporossi
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
| | - Stanislao Rizzo
- Ophthalmology Unit, Fondazione Policlinico Universitario A. Gemelli, IRCCS, 00168 Rome, Italy; (T.C.); (U.D.V.); (A.S.); (A.B.); (A.C.); (S.R.)
- Ophthalmology Unit, Catholic University “Sacro Cuore”, 00168 Rome, Italy
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19
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Ibarz Barberá M, Morales Fernández L, Tañá Rivero P, Gómez de Liaño R, Teus MA. Anterior-segment optical coherence tomography of filtering blebs in the early postoperative period of ab externo SIBS microshunt implantation with mitomycin C: Morphological analysis and correlation with intraocular pressure reduction. Acta Ophthalmol 2022; 100:e192-e203. [PMID: 33838021 DOI: 10.1111/aos.14863] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2020] [Revised: 02/27/2021] [Accepted: 03/16/2021] [Indexed: 12/16/2022]
Abstract
PURPOSE To analyse the morphological evolution of filtering blebs with anterior-segment OCT (AS-OCT) and its correlation with intraocular pressure after ab externo SIBS microshunt implantation with mitomycin C (MMC) during a 3-month follow-up period. METHODS Twenty-eight filtering blebs of 28 patients with open-angle glaucoma were measured horizontally and vertically in the sub-Tenon space with AS-OCT after ab externo SIBS microshunt implantation with MMC. The intraocular pressure (IOP) was monitored simultaneously at each visit. Maturation of and morphological changes in the blebs and correlations with the IOP were recorded. RESULTS The average median preoperative IOP of 20.7 (range, 12-30) mmHg decreased to 8.5 (range, 4-17), 8.9 (range, 5-17), 10.4 (range, 8-16) and 10.9 (range, 9-15) mmHg at 24 hr, 1 week, 1 month and 3 months, respectively (p < 0.001). A multiform morphology on AS-OCT prevailed at all time points, with a 3.5% rate of a uniform bleb morphology at the first week. The horizontal and vertical diameters of the blebs increased from baseline to the third month. The horizontal expansion (406 ± 127 μm on day 7, p = 0.04, 712 ± 211 μm on day 30, p = 0.02 and 952 ± 218 μm on day 90, p < 0.001) was greater than the vertical expansion (16 ± 18 μm, p = 0.3 on day 1, 63 ± 27 μm, p = 0.02 on day 30 and 137 ± 34 μm, p < 0.001 on day 90) without correlation with the IOP (r = -0.3, p = 0.2). CONCLUSION Anterior-segment OCT (AS-OCT) of the filtering blebs formed after ab externo SIBS microshunt implantation showed progressive horizontal and vertical expansion of the blebs in the sub-Tenon space, with a significant peak at the first month not significantly correlated with the decrease in the IOP.
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Affiliation(s)
| | | | | | | | - Miguel A. Teus
- Hospital Clínico Madrid Spain
- Clínica Novovisión Madrid Spain
- Hospital Universitario Príncipe de Asturias Alcalá de Henares, Madrid Spain
- Universidad de Alcalá Alcalá de Henares, Madrid Spain
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van Mechelen RJS, Wolters JE, Bertens CJF, Webers CAB, van den Biggelaar FJHM, Gorgels TGMF, Beckers HJM. Animal models and drug candidates for use in glaucoma filtration surgery: A systematic review. Exp Eye Res 2022; 217:108972. [PMID: 35114212 DOI: 10.1016/j.exer.2022.108972] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2021] [Revised: 01/14/2022] [Accepted: 01/26/2022] [Indexed: 12/17/2022]
Abstract
Glaucoma, a degenerative disease of the optic nerve, is the leading cause of irreversible blindness worldwide. Currently, there is no curative treatment. The only proven treatment is lowering intraocular pressure (IOP), the most important risk factor. Glaucoma filtration surgery (GFS) can effectively lower IOP. However, approximately 10% of all surgeries fail yearly due to excessive wound healing, leading to fibrosis. GFS animal models are commonly used for the development of novel treatment modalities. The aim of the present review was to provide an overview of available animal models and anti-fibrotic drug candidates. MEDLINE and Embase were systematically searched. Manuscripts until September 1st, 2021 were included. Studies that used animal models of GFS were included in this review. Additionally, the snowball method was used to identify other publications which had not been identified through the systematic search. Two hundred articles were included in this manuscript. Small rodents (e.g. mice and rats) are often used to study the fibrotic response after GFS and to test drug candidates. Due to their larger eyes, rabbits are better suited to develop medical devices. Novel drugs aim to inhibit specific pathways, e.g. through the use of modulators, monoclonal antibodies, aqueous suppressants or gene therapy. Although most newly studied drugs offer a higher safety profile compared to antimetabolites, their efficacy is in most cases lower when compared to MMC. Current literature on animal models and potential drug candidates for GFS were summarized in this review. Future research should focus on refining current animal models (for example through the induction of glaucoma prior to undertaking GFS) and standardizing animal research to ensure a higher reproducibility and reliability across different research groups. Lastly, novel therapies need to be further optimized, e.g. by conducting more research on the dosage, administration route, application frequency, the option of creating combination therapies, or the development of drug delivery systems for sustained release of anti-fibrotic medication.
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Affiliation(s)
- Ralph J S van Mechelen
- University Eye Clinic Maastricht, Maastricht University Medical Center+ (MUMC+), 6202 AZ, Maastricht, the Netherlands; School for Mental Health and Neuroscience, Maastricht University, 6229 ER, Maastricht, the Netherlands; Chemelot Institute for Science and Technology (InSciTe), 6229 GS, Maastricht, the Netherlands.
| | - Jarno Ej Wolters
- University Eye Clinic Maastricht, Maastricht University Medical Center+ (MUMC+), 6202 AZ, Maastricht, the Netherlands; School for Mental Health and Neuroscience, Maastricht University, 6229 ER, Maastricht, the Netherlands; Chemelot Institute for Science and Technology (InSciTe), 6229 GS, Maastricht, the Netherlands
| | - Christian J F Bertens
- University Eye Clinic Maastricht, Maastricht University Medical Center+ (MUMC+), 6202 AZ, Maastricht, the Netherlands; School for Mental Health and Neuroscience, Maastricht University, 6229 ER, Maastricht, the Netherlands; Chemelot Institute for Science and Technology (InSciTe), 6229 GS, Maastricht, the Netherlands
| | - Carroll A B Webers
- University Eye Clinic Maastricht, Maastricht University Medical Center+ (MUMC+), 6202 AZ, Maastricht, the Netherlands
| | - Frank J H M van den Biggelaar
- University Eye Clinic Maastricht, Maastricht University Medical Center+ (MUMC+), 6202 AZ, Maastricht, the Netherlands
| | - Theo G M F Gorgels
- University Eye Clinic Maastricht, Maastricht University Medical Center+ (MUMC+), 6202 AZ, Maastricht, the Netherlands
| | - Henny J M Beckers
- University Eye Clinic Maastricht, Maastricht University Medical Center+ (MUMC+), 6202 AZ, Maastricht, the Netherlands
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21
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Ahmed T, Honjo M, Sakata R, Fujishiro T, Shirato S, Aihara M. Long-term results of the safety and effectiveness of a novel microshunt in Japanese patients with primary open-angle glaucoma. Jpn J Ophthalmol 2022; 66:33-40. [PMID: 34988757 DOI: 10.1007/s10384-021-00893-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Accepted: 09/17/2021] [Indexed: 11/29/2022]
Abstract
PURPOSE To evaluate the long-term safety and effectiveness of the Preserflo MicroShunt in Japanese primary open-angle glaucoma (POAG) patients. STUDY DESIGN Single-site, nonrandomized observational study. PATIENTS AND METHODS Eight eyes of 7 POAG patients were included. The surgical complications and interventions were monitored. The preoperative and postoperative intraocular pressures (IOPs), numbers of antiglaucoma medications, logarithm of the minimum angle of resolution visual acuity (VA), mean deviation (MD) slope, and corneal endothelial cell density (CECD) were compared retrospectively. RESULTS The mean follow-up period was 68.9 months (range, 48-76 months). The baseline IOP of 17.9 ± 3.5 mmHg and the number of glaucoma medications of 3.5 ± 0.5 were significantly reduced at subsequent follow-up visits. At 1, 2, 3, 4, 5, and 6 years postoperatively, the IOPs were 13.8 ± 2.9, 12.8 ± 2.3, 12.1 ± 3.2, 12.6 ± 2.5, 12.3 ± 1.0, and 13.5 ± 3.1 mmHg, respectively, with the use of 1.6 ± 1.4, 1.6 ± 1.6, 1.5 ± 1.4, 1.5 ± 1.4, 1.9 ± 1.3, and 2.0 ± 1.1 medications. Postoperative transient hyphema occurred in 1 eye. Postoperative needling was required in 5 eyes, 12 times in total. No eyes showed significant VA decline, except for 1 eye with a severe central visual field defect that existed preoperatively. The preoperative MD slope of - 1.6 ± 1.2 dB/year improved significantly, to - 0.3 ± 0.2 dB/year (P = 0.023), postoperatively. The baseline CECD decreased from 2595 ± 292 to 2478.4 ± 255 postoperatively. CONCLUSION The microshunt surgical procedure is safe and effective for Japanese POAG patients.
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Affiliation(s)
- Tazbir Ahmed
- Department of Ophthalmology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan
| | - Megumi Honjo
- Department of Ophthalmology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.,Yotsuya-Shirato Eye Clinic, Tokyo, Japan
| | - Rei Sakata
- Department of Ophthalmology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.,Yotsuya-Shirato Eye Clinic, Tokyo, Japan
| | - Takashi Fujishiro
- Department of Ophthalmology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan.,Yotsuya-Shirato Eye Clinic, Tokyo, Japan
| | | | - Makoto Aihara
- Department of Ophthalmology, University of Tokyo School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8655, Japan. .,Yotsuya-Shirato Eye Clinic, Tokyo, Japan.
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22
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Seet LF, Yap ZL, Chu SWL, Toh LZ, Ibrahim FI, Teng X, Wong TT. Effects of Valproic Acid and Mitomycin C Combination Therapy in a Rabbit Model of Minimally Invasive Glaucoma Surgery. Transl Vis Sci Technol 2022; 11:30. [PMID: 35044442 PMCID: PMC8787605 DOI: 10.1167/tvst.11.1.30] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose This study aimed to compare the effectiveness of combination therapy consisting of low-dose mitomycin C (MMC) and valproic acid (VPA) against high-dose MMC for improving the scar phenotype in minimally invasive glaucoma surgery (MIGS). Methods A rabbit model of MIGS incorporating the PreserFlo MicroShunt was treated with high (0.4 mg/mL) or low (0.1 mg/mL) doses of MMC or with combination therapy consisting of low-dose (0.1 mg/mL) MMC and VPA. Operated eyes were examined by live ocular imaging, histochemical evaluation, multiphoton quantitation of collagen characteristics, and molecular analyses. Results Although high-dose MMC obliterated the vasculature, combination therapy vastly improved the postoperative tissue morphology by maintaining the vasculature without increased vascularization. Combination therapy also altered collagen morphology and reduced encapsulation of the MicroShunt distal end, which remained at risk with MMC treatment alone. Multiphoton quantitation indicated that the combination therapy significantly reduced collagen density and fiber dimensions compared with monotherapy. At the molecular level, combination therapy significantly reduced Vegfa, Vegfc, and Vegfd expression and inhibited Col1a1 upregulation from baseline levels, all of which low-dose MMC alone was unable to achieve. Notably, COL1A1 protein levels appeared more consistently suppressed by combination therapy compared with high-dose MMC alone. Conclusions Compared with high-dose MMC, combination therapy was less toxic by sparing the vasculature and potentially more effective in reducing scarring via the regulation of collagen content and organization. Translational Relevance VPA may be combined with low-dose MMC to replace high-dose MMC to deliver safe and effective anti-scarring outcomes.
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Affiliation(s)
- Li-Fong Seet
- Singapore Eye Research Institute, Singapore.,Duke-NUS Medical School Singapore, Singapore
| | - Zhu Li Yap
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School Singapore, Singapore.,Singapore National Eye Centre, Singapore
| | | | | | | | | | - Tina T Wong
- Singapore Eye Research Institute, Singapore.,Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Duke-NUS Medical School Singapore, Singapore.,Singapore National Eye Centre, Singapore
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Abstract
A novel polyolefin called poly(styrene-block-isobutylene-block-styrene) (“SIBS”) originated from Joseph P. Kennedy's laboratory at the University of Akron (Akron, Ohio, United States) and was developed as a biomaterial for long-term implant applications by the author. SIBS has no cleavable groups on its backbone or sidechains, is comprised predominantly of alternating secondary and quaternary carbons on its backbone, which prevents embrittlement and cracking under flexion, and undergoes multiple purification steps which renders it extremely biocompatible and well-suited for long-term applications in the eye. This article explores two ophthalmic devices; 1) the PRESERFLO® MicroShunt (Santen Pharmaceutical Co. Ltd., Osaka, Japan) made from SIBS that lowers intraocular pressure to thwart progression of vision loss from glaucoma, and 2) a novel intraocular lens (IOL) made from crosslinked polyisobutylene, which is under-development by Xi'an Eyedeal Medical Technology Co., Ltd. (Xi'an, China) that does not glisten nor cloud over time, as do most conventional IOLs. A novel class of ultra-biostable polyisobutylene-based biomaterials for long-term implant applications. A novel class of polyisobutylene-based biomaterials that is not bioactive and elicits minimal foreign body reaction. A device called the PRESERFLO® MicroShunt to treat glaucoma made from poly(styrene-block-isobutylene-block-styrene) (SIBS). A novel crosslinked polyisobutylene material for intraocular lens applications that eliminates glistenings and halos.
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Affiliation(s)
- Leonard Pinchuk
- Distinguished Research Professor of Biomedical Engineering, University of Miami, Biomedical Engineering Dept., 13704 SW 92nd Court, Miami, 33176, FL, United States.,Founder and Senior Vice President, InnFocus, Inc., a Santen company, Miami, FL, United States
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24
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Pereira ICF, van de Wijdeven R, Wyss HM, Beckers HJM, den Toonder JMJ. Conventional glaucoma implants and the new MIGS devices: a comprehensive review of current options and future directions. Eye (Lond) 2021; 35:3202-3221. [PMID: 34127842 PMCID: PMC8602385 DOI: 10.1038/s41433-021-01595-x] [Citation(s) in RCA: 39] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 04/19/2021] [Accepted: 05/05/2021] [Indexed: 02/05/2023] Open
Abstract
Glaucoma is a progressive optic neuropathy that is the second leading cause of preventable blindness worldwide, after cataract formation. A rise in the intraocular pressure (IOP) is considered to be a major risk factor for glaucoma and is associated with an abnormal increase of resistance to aqueous humour outflow from the anterior chamber. Glaucoma drainage devices have been developed to provide an alternative pathway through which aqueous humour can effectively exit the anterior chamber, thereby reducing IOP. These devices include the traditional aqueous shunts with tube-plate design, as well as more recent implants, such as the trabeculectomy-modifying EX-PRESS® implant and the new minimally invasive glaucoma surgery (MIGS) devices. In this review, we will describe each implant in detail, focusing on their efficacy in reducing IOP and safety profile. Additionally, a critical and evidence-based comparison between these implants will be provided. Finally, we will propose potential developments that may help to improve the performance of current devices.
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Affiliation(s)
- Inês C. F. Pereira
- grid.6852.90000 0004 0398 8763Microsystems Research Section, Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands ,grid.6852.90000 0004 0398 8763Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Rosanne van de Wijdeven
- grid.6852.90000 0004 0398 8763Microsystems Research Section, Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands ,grid.6852.90000 0004 0398 8763Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Hans M. Wyss
- grid.6852.90000 0004 0398 8763Microsystems Research Section, Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands ,grid.6852.90000 0004 0398 8763Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, The Netherlands
| | - Henny J. M. Beckers
- grid.412966.e0000 0004 0480 1382University Eye Clinic Maastricht, Maastricht University Medical Centre+ (MUMC+), Maastricht, The Netherlands
| | - Jaap M. J. den Toonder
- grid.6852.90000 0004 0398 8763Microsystems Research Section, Department of Mechanical Engineering, Eindhoven University of Technology, Eindhoven, The Netherlands ,grid.6852.90000 0004 0398 8763Institute for Complex Molecular Systems (ICMS), Eindhoven University of Technology, Eindhoven, The Netherlands
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25
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Kao BW, Meer E, Barbolt TA, Lewis RA, Ahmed II, Lee V, Nicaise SM, Griggs G, Miller-Ellis EG. Biocompatibility and feasibility of VisiPlate, a novel ultrathin, multichannel glaucoma drainage device. J Mater Sci Mater Med 2021; 32:141. [PMID: 34817711 PMCID: PMC8613174 DOI: 10.1007/s10856-021-06613-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Accepted: 10/12/2021] [Indexed: 06/13/2023]
Abstract
BACKGROUND Glaucoma is the leading cause of blindness worldwide. Glaucoma drainage devices and minimally invasive glaucoma surgeries (MIGS) often present with tradeoffs in safety and durability of efficacy. Using a rabbit model, we examined the biocompatibility and feasibility of VisiPlate, a novel, ultrathin, tubeless subconjunctival shunt comprised of a network of microchannels. METHODS Six naive female New Zealand White rabbits received implants (three only in the right eye with contralateral eye untreated and three in both eyes) composed of a 400-nm-thick aluminum oxide core coated with 2 µm of parylene-C, manufactured with microelectromechanical systems (MEMS) techniques. Tonometry, slit lamp exam, clinical exam, fluorescein patency testing, and histopathology were performed. RESULTS VisiPlate demonstrated IOP-lowering of 20-40% compared to baseline at each time point over the course of 3 months in the nine implanted eyes. All eyes developed blebs over the implant, and fluorescein testing demonstrated fluid patency at 22 days post-implantation. Slit lamp and clinical observations showed that VisiPlate was well tolerated, with low levels of conjunctival congestion, conjunctival swelling, aqueous flare, hyphema, and iris involvement from surgery that resolved over time. At sacrifice time points of 93 days and 180 days, the only notable observations were mild levels of conjunctival congestion in implanted eyes. Histopathology showed minimal tissue response and no obvious inflammation, fibrosis, or necrosis around the implant. CONCLUSIONS The results of this in vivo study demonstrate the biocompatibility and IOP-lowering effect of a multichannel, ultrathin subconjunctival shunt in a rabbit model. The data suggest that VisiPlate may safely enhance aqueous outflow and significantly reduce intraocular pressure.
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Affiliation(s)
- Brandon W Kao
- Avisi Technologies, Philadelphia, PA, USA.
- University of California San Francisco, San Francisco, CA, USA.
| | - Elana Meer
- University of Pennsylvania, Philadelphia, PA, USA.
| | | | | | - Iqbal Ike Ahmed
- Ophthalmology & Vision Sciences, University of Toronto, Toronto, ON, Canada
| | - Vivian Lee
- University of Pennsylvania, Philadelphia, PA, USA
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Yazgan S, Tekin IO, Akpolat N, Koc O. Novel Bacterial Cellulose Membrane to Reduce Fibrosis Following Trabeculectomy. J Glaucoma 2021; 30:1001-1010. [PMID: 34224487 DOI: 10.1097/ijg.0000000000001907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 06/20/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE The aim was to evaluate the effectiveness of bacterial cellulose membrane (BCM) in preventing fibrosis in trabeculectomy and the biocompatibility of BCM with conjunctiva and sclera. MATERIALS AND METHODS Twenty-one eyes of 21 adult rabbits underwent fornix-based trabeculectomy. Standard surgery was done to control group (CG, n=7). Mitomycin-C (MMC) (0.3 mg/mL, 3 min) was applied to MMC group only (MMCG, n=7). BCM (~100 µm thick, 10×10 mm, single layer) was covered on the sclerotomy area before conjunctiva was closed in BCM group (BCMG, n=7). Intraocular pressures (IOP) were measured before, and 7, 14, 28, and 45 days after surgery (IOP-POD7, POD14, POD28, POD45). The IOP decrease were expressed as DIOP%-POD7, DIOP%-POD14, DIOP%-POD28, and DIOP%-POD45. The rabbits were sacrificed on the 45th day. Conjunctival vessel number, degrees of fibrosis, total inflammation, foreign body reaction, inflammatory cell types (B cells, T cells, plasma cells), macrophages, bleb spaces and the expression of α-smooth muscle actin were studied using histopathology and immunohistochemistry techniques. The groups were compared using nonparametric tests. RESULTS There was no statistically significant difference between the groups regarding baseline IOP and DIOP%-POD7 (P>0.05). While DIOP%-POD14, 28 and 45 were similar between BCMG and MMCG, they were significantly lower in CG (P<0.05). The lowest conjunctival vessel number was detected in the MMCG but the difference was not significant. There was no difference between BCMG and CG with regard to the numbers of B cells, T cells, and macrophages, however, these cells were significantly lower in MMCG (P<0.05). Five cases had mild and 2 cases had moderate foreign body reaction in the BCMG. There was mild to moderate inflammation in all BCM cases. While fibrosis and α-smooth muscle actin staining were higher in the CG (P<0.001), they were minimal in the BCM and MMCGs. CONCLUSIONS BCM showed good biocompatibility and provided better control of IOP with minimal fibrosis at the trabeculectomy site compared with the control group.
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Affiliation(s)
| | - Ishak Ozel Tekin
- Department of Immunology, Faculty of Medicine, Bulent Ecevit University, Zonguldak, Turkey
| | - Nusret Akpolat
- Pathology, Faculty of Medicine, Inonu University, Malatya
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Nobl M, Freissinger S, Kassumeh S, Priglinger S, Mackert MJ. One-year outcomes of microshunt implantation in pseudoexfoliation glaucoma. PLoS One 2021; 16:e0256670. [PMID: 34449795 PMCID: PMC8396760 DOI: 10.1371/journal.pone.0256670] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Accepted: 08/11/2021] [Indexed: 11/19/2022] Open
Abstract
PURPOSE To compare the safety and efficacy of microshunt implantation augmented with Mitomycin C in patients with pseudoexfoliation glaucoma (PEXG) and primary open-angle glaucoma (POAG). METHODS In this retrospective, single centre, interventional study, 46 eyes of 41 patients with PEXG (20 eyes) and POAG (26 eyes) underwent microshunt implantation. Definition of failure was an intraocular pressure (IOP) lower than 5 or higher than 17mmHg on two consecutive visits, an IOP reduction lower than 20% on two consecutive visits, the need of surgical revisions or reoperations or loss of light perception. Outcome was rated as complete success if achieved without medication, otherwise as qualified success. Furthermore, postoperative complications and interventions were compared between the two groups. RESULTS Patient demographics were similar, except for older age in the PEXG group (70.9±8.6 versus 77.6±8; p = 0.02). Mean IOP dropped from 21.5±5.8mmHg (PEXG) and 18.2±4.5mmHg (POAG) at baseline to 12.8±3.0mmHg (p<0.0001) and 12.9±4.2mmHg (p<0.0001), respectively, at one year. Mean number of medications were reduced from 2.8±1.3 to 0.3±0.8 for PEXG patients (p<0.0001) and from 2.7±1.3 to 0.3±0.8 for POAG patients (p<0.0001). At one year of follow-up 75.0% of PEXG patients achieved complete success and 80.0% qualified success. In the POAG group rates were 73.1% and 76.9%, respectively. Postoperative complications were comparable between both groups, except for higher rates of hypotony (p = 0.04) and choroidal detachment (p = 0.03) in the PEXG group. CONCLUSION Microshunt implantation demonstrated similar efficacy results in PEXG and POAG eyes at a follow-up of 12 months. Higher rates of transient hypotony and choroidal detachment were observed in PEXG eyes.
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Affiliation(s)
- Matthias Nobl
- Department of Ophthalmology, Ludwig-Maximilians-University Munich, Munich, Germany
- * E-mail:
| | - Sigrid Freissinger
- Department of Ophthalmology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Stefan Kassumeh
- Department of Ophthalmology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Siegfried Priglinger
- Department of Ophthalmology, Ludwig-Maximilians-University Munich, Munich, Germany
| | - Marc J. Mackert
- Department of Ophthalmology, Ludwig-Maximilians-University Munich, Munich, Germany
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Fujimoto T, Nakashima KI, Watanabe-Kitamura F, Watanabe T, Nakamura K, Maki K, Shimazaki A, Kato M, Tanihara H, Inoue T. Intraocular Pressure-Lowering Effects of Trabeculectomy Versus MicroShunt Insertion in Rabbit Eyes. Transl Vis Sci Technol 2021; 10:9. [PMID: 34357381 PMCID: PMC8354029 DOI: 10.1167/tvst.10.9.9] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Purpose To compare the surgical results of PRESERFLO MicroShunt (MicroShunt) insertion and trabeculectomy in rabbit eyes. Methods Trabeculectomy or MicroShunt insertion was performed on the eyes of Japanese white rabbits. Intraocular pressure (IOP) was measured on conscious rabbits using a rebound tonometer for up to 12 weeks after surgery. Filtering bleb appearance was evaluated. Scarring in the filtering bleb was assessed by immunohistochemical analyses. The change in mRNA expression in the conjunctiva was evaluated using RNA sequence analyses. Results The preoperative IOP of the operative eye did not differ significantly between trabeculectomy (11.6 ± 1.0 mmHg, n = 10) and MicroShunt insertion (12.6 ± 1.3 mmHg, n = 10). In both groups, the IOP of the operative eye was significantly lower than that of the contralateral eye at one day postoperatively, which continued until 12 weeks after surgery. The peak differences in IOP were −8.4 ± 3.0 (trabeculectomy) and −8.1 ± 2.1 mmHg (MicroShunt) at two weeks after surgery; no significant differences were observed in IOP reduction between the groups. Appearance and immunohistochemical analyses of the filtering bleb showed no significant difference between the groups. Moreover, RNA sequence analysis results showed no difference between the groups in mRNA expression fluctuations. Conclusions Postoperative IOP, bleb appearance, and immunohistochemical analysis results were similar in the trabeculectomy and MicroShunt groups, indicating that MicroShunt insertion is as effective as trabeculectomy in lowering IOP. Translational Relevance Comparison of surgical procedures using animal models has made it possible to predict clinical efficacy and safety.
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Affiliation(s)
- Tomokazu Fujimoto
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kei-Ichi Nakashima
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | | | - Takahiro Watanabe
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kenichi Nakamura
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | | | | | | | - Hidenobu Tanihara
- Director of Kumamoto University Hospital, Kumamoto University, Kumamoto, Japan
| | - Toshihiro Inoue
- Department of Ophthalmology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
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Zhang Y, Kang K, Zhu N, Li G, Zhou X, Zhang A, Yi Q, Wu Y. Bottlebrush-like highly efficient antibacterial coating constructed using α-helical peptide dendritic polymers on the poly(styrene- b-(ethylene- co-butylene)- b-styrene) surface. J Mater Chem B 2021; 8:7428-7437. [PMID: 32662494 DOI: 10.1039/d0tb01336f] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Infectious diseases induced by pathogenic bacteria are the major causes for the failure of medical implants. Meanwhile, the drug-resistance is steadily developed because of the large and even inappropriate use of antibiotics. Therefore, the development of antibacterial coating with non-antibiotic-based agents on the surfaces of medical implants and devices has been an urgent need. Herein, we propose a bottlebrush-like antibacterial coating on a poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) triblock copolymer surface by UV-induced graft polymerization of poly(ethylene glycol) (PEG) acrylate terminated poly(lysine dendrimer). This PEG-conjugated antibacterial polymer possessed a substructure of α-helical backbone and cation dendrimer side chains stretching in the radial directions of the helix. The introduction of lysine peptide dendrimers endowed the prepared antibacterial polymer with precisely controlled characteristics of its local cation density, amphipathic composition as well as three-dimensional (3D) conformation to improve interactions with bacterial membranes. The antimicrobial assay and biocompatibility assay results showed that 96.83% of S. aureus and 99.99% of E. coli were killed after being in contact with the antibacterial coating, while no toxicity to mammalian cells or no hemolysis was detected. This antimicrobial activity was further confirmed by the molecular dynamics simulation results, which demonstrated that the employment of lysine peptide dendrimers enhanced the electrostatic interaction and hydrogen bonding between the brush and bacterial membranes remarkably. Such bottlebrush-like antibacterial coating constructed using α-helical peptide dendritic polymers may become an effective strategy for manufacturing antibacterial products for biomedical uses.
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Affiliation(s)
- Yujia Zhang
- National Engineering Research Center for Biomaterials, Sichuan University, Chengdu 610064, P. R. China.
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Parikh KS, Josyula A, Omiadze R, Ahn JY, Ha Y, Ensign LM, Hanes J, Pitha I. Nano-structured glaucoma drainage implant safely and significantly reduces intraocular pressure in rabbits via post-operative outflow modulation. Sci Rep 2020; 10:12911. [PMID: 32737340 PMCID: PMC7395089 DOI: 10.1038/s41598-020-69687-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 07/14/2020] [Indexed: 12/21/2022] Open
Abstract
Glaucoma is a leading cause of irreversible vision loss predicted to affect more than 100 million people by 2040. Intraocular pressure (IOP) reduction prevents development of glaucoma and vision loss from glaucoma. Glaucoma surgeries reduce IOP by facilitating aqueous humor outflow through a vent fashioned from the wall of the eye (trabeculectomy) or a glaucoma drainage implant (GDI), but surgeries lose efficacy overtime, and the five-year failure rates for trabeculectomy and tube shunts are 25-45%. The majority of surgical failures occur due to fibrosis around the vent. Alternatively, surgical procedures can shunt aqueous humor too well, leading to hypotony. Electrospinning is an appealing manufacturing platform for GDIs, as it allows for incorporation of biocompatible polymers into nano- or micro-fibers that can be configured into devices of myriad combinations of dimensions and conformations. Here, small-lumen, nano-structured glaucoma shunts were manufactured with or without a degradable inner core designed to modulate aqueous humor outflow to provide immediate IOP reduction, prevent post-operative hypotony, and potentially offer significant, long-term IOP reduction. Nano-structured shunts were durable, leak-proof, and demonstrated biocompatibility and patency in rabbit eyes. Importantly, both designs prevented hypotony and significantly reduced IOP for 27 days in normotensive rabbits, demonstrating potential for clinical utility.
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Affiliation(s)
- Kunal S Parikh
- Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Center for Bioengineering Innovation & Design, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Aditya Josyula
- Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Revaz Omiadze
- Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Ju Young Ahn
- Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Youlim Ha
- Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
| | - Laura M Ensign
- Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Justin Hanes
- Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
- Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, MD, 21218, USA
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
- Departments of Environmental Health Sciences, Oncology, and Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA
| | - Ian Pitha
- Center for Nanomedicine, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA.
- Department of Ophthalmology, Wilmer Eye Institute, Johns Hopkins University School of Medicine, Baltimore, MD, 21231, USA.
- Glaucoma Center of Excellence, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD, 21287, USA.
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Sarkisian SR Jr, Radcliffe N, Harasymowycz P, Vold S, Patrianakos T, Zhang A, Herndon L, Brubaker J, Moster R, Francis B; ASCRS Glaucoma Clinical Committee. Visual outcomes of combined cataract surgery and minimally invasive glaucoma surgery. J Cataract Refract Surg 2020; 46:1422-32. [PMID: 32657904 DOI: 10.1097/j.jcrs.0000000000000317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Minimally invasive glaucoma surgery (MIGS) has become a reliable standard of care for the treatment of glaucoma when combined with cataract surgery. This review describes the MIGS procedures currently combined with and without cataract surgery with a focus on visual outcomes based on the literature and the experience of the ASCRS Glaucoma Clinical Committee.
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Schlenker MB, Durr GM, Michaelov E, Ahmed IIK. Intermediate Outcomes of a Novel Standalone Ab Externo SIBS Microshunt With Mitomycin C. Am J Ophthalmol 2020; 215:141-53. [PMID: 32173344 DOI: 10.1016/j.ajo.2020.02.020] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 02/13/2020] [Accepted: 02/24/2020] [Indexed: 10/24/2022]
Abstract
PURPOSE To determine the efficacy, risk factors for failure, and adverse events of a standalone novel ab externo SIBS microshunt with mitomycin C (MMC) during 1-year follow-up. DESIGN Retrospective, interventional case series. SUBJECTS Glaucomatous eyes with an intraocular pressure (IOP) above target and/or progressing on maximally tolerated medical therapy. METHODS Consecutive patients with open-angle glaucoma (OAG) and no previous filtering surgery received an ab externo SIBS microshunt with MMC from July 2015 to November 2017. Main outcome measures were proportion of eyes at 1-year with (1) no 2 consecutive IOP readings >17 mm Hg or clinical hypotony without (complete) or with glaucoma medications (qualified); and (2) at least a 20% reduction from decision IOP. Secondary outcomes included upper IOP thresholds of 14 mm Hg and 21 mm Hg with and without a 20% IOP reduction from baseline, median IOP, medications, risk factors for failure, interventions, complications, and reoperations. RESULTS A total of 164 eyes in 132 patients were included. Complete success was achieved in 76.9% of eyes, qualified success in 92.5%. Complete success was 75.6% for an upper IOP cut-off of 14 mm Hg and 76.9% for 21 mm Hg, and qualified success was 91.9% and 92.5%. MMC dose of 0.2 vs 0.4-0.5 mg/mL (hazard ratio [HR] 2.51; 95% CI 1.12-5.65) and primary open-angle glaucoma vs secondary open-angle glaucoma (SOAG) (HR 2.51; 95% CI 1.01-6.23) represented the only risk factors for failure in multivariable analysis. Needling was performed in 8.5% of eyes. Two eyes received surgical revision, and 1 a reoperation. CONCLUSIONS One-year results of the ab externo SIBS microshunt demonstrated promising rates of qualified and complete success, decreased drop use, few complications, and infrequent postoperative interventions.
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Bell K, de Padua Soares Bezerra B, Mofokeng M, Montesano G, Nongpiur ME, Marti MV, Lawlor M. Learning from the past: Mitomycin C use in trabeculectomy and its application in bleb-forming minimally invasive glaucoma surgery. Surv Ophthalmol 2020; 66:109-123. [PMID: 32450159 DOI: 10.1016/j.survophthal.2020.05.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2019] [Revised: 05/14/2020] [Accepted: 05/15/2020] [Indexed: 12/26/2022]
Abstract
Trabeculectomy has been performed since the mid-1960s and remains the gold standard for glaucoma surgery. Newer surgical options have evolved, collectively referred to as minimally invasive glaucoma surgeries. Despite producing large intraocular pressure decreases, full-thickness procedures into the subconjunctival space may be limited by fibrosis. Mitomycin C (MMC) and 5-fluorouracil have been in use with trabeculectomy with good evidence of significantly increased success at the cost, however, of an increased risk of complications. Off-label MMC application can be found in almost all clinical trials, including in combination with minimally invasive glaucoma surgeries. We explore current evidence for MMC use in trabeculectomy and how this may differ for minimally invasive glaucoma surgery devices and analyze the range of agents and doses that are used. Although we found that most studies could not show any correlation between MMC dosage and the surgical outcome, the success rates with the Xen® microshunt seemed to be higher when using 20 mcg of MMC than when using 10 mcg. Certain important methodological considerations make this hard to confirm definitively, and other factors such as placement of the device may play a more substantial role. For the PreserFlo® microshunt, preliminary data suggest higher success rates with higher MMC dosage at the cost of higher device-related adverse events and reoperations. Although the ideal dose still needs to be established, it seems very likely that MMC provides significant improvement in outcomes in bleb-forming minimally invasive glaucoma procedures.
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Affiliation(s)
- Katharina Bell
- Experimental and Translational Ophthalmology, Department of Ophthalmology, Medical Center of the Johannes Gutenberg University Mainz, Mainz, Rhineland-Palatinate, Germany.
| | | | | | - Giovanni Montesano
- University of Milan - ASST Santi Paolo e Carlo, Milan, Italy; City, University of London - Optometry and Visual Sciences, London, United Kingdom; NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust, UCL Institute of Ophthalmology, London, United Kingdom
| | | | | | - Mitchell Lawlor
- Save Sight Institute, Faculty of Medicine and Health, University of Sydney, Sydney, Australia; Sydney Eye Hospital, Macquarie St, Sydney, Australia
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Sadruddin O, Pinchuk L, Angeles R, Palmberg P. Ab externo implantation of the MicroShunt, a poly (styrene- block-isobutylene- block-styrene) surgical device for the treatment of primary open-angle glaucoma: a review. Eye Vis (Lond) 2019; 6:36. [PMID: 31807606 PMCID: PMC6857290 DOI: 10.1186/s40662-019-0162-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/03/2019] [Accepted: 10/17/2019] [Indexed: 12/31/2022]
Abstract
Trabeculectomy remains the ‘gold standard’ intraocular pressure (IOP)-lowering procedure for moderate-to-severe glaucoma; however, this approach is associated with the need for substantial post-operative management. Micro-invasive glaucoma surgery (MIGS) procedures aim to reduce the need for intra- and post-operative management and provide a less invasive means of lowering IOP. Generally, MIGS procedures are associated with only modest reductions in IOP and are targeted at patients with mild-to-moderate glaucoma, highlighting an unmet need for a less invasive treatment of advanced and refractory glaucoma. The PRESERFLO® MicroShunt (formerly known as InnFocus MicroShunt) is an 8.5 mm-long (outer diameter 350 μm; internal lumen diameter 70 μm) glaucoma drainage device made from a highly biocompatible, bioinert material called poly (styrene-block-isobutylene-block-styrene), or SIBS. The lumen size is sufficiently small that at normal aqueous flow hypotony is avoided, but large enough to avoid being blocked by sloughed cells or pigment. The MicroShunt achieves the desired pressure range in the eye by draining aqueous humor from the anterior chamber to a bleb formed under the conjunctiva and Tenon’s capsule. The device is implanted ab externo with intraoperative Mitomycin C via a minimally invasive (relative to incisional surgery) surgical procedure, enabling precise control of placement without the need for gonioscopy, suture tension control, or suture lysis. The implantation procedure can be performed in combination with cataract surgery or as a standalone procedure. The MicroShunt received Conformité Européenne (CE) marking in 2012 and is intended for the reduction of IOP in eyes of patients with primary open-angle glaucoma in which IOP remains uncontrolled while on maximum tolerated medical therapy and/or in which glaucoma progression warrants surgery. Three clinical studies assessing the long-term safety and efficacy of the MicroShunt have been completed; a Phase 3 multicenter, randomized clinical study comparing the MicroShunt to primary trabeculectomy is underway. In preliminary studies, the MicroShunt effectively reduced IOP and use of glaucoma medications up to 3 years after implantation, with an acceptable safety profile. This article summarizes current literature on the unique properties of the MicroShunt, the preliminary efficacy and safety findings, and discusses its potential use as an alternative to trabeculectomy for glaucoma surgery.
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Affiliation(s)
| | | | | | - Paul Palmberg
- 3Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL USA
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Lee RMH, Bouremel Y, Eames I, Brocchini S, Khaw PT. Translating Minimally Invasive Glaucoma Surgery Devices. Clin Transl Sci 2019; 13:14-25. [PMID: 31568666 PMCID: PMC6951459 DOI: 10.1111/cts.12660] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 05/08/2019] [Indexed: 11/30/2022] Open
Abstract
Glaucoma is the leading cause of irreversible blindness with over 70 million people affected worldwide. The surgical management of glaucoma aims to lower intraocular pressure by increasing aqueous outflow facility. The latest manufacturing techniques have allowed for the development of a number of novel implantable devices to improve safety and outcomes of glaucoma surgery. These are collectively referred to as minimally invasive glaucoma surgery (MIGS) devices and are among the smallest devices implanted in the human body. This review discusses the design criterion and constraints as well as the user requirements for MIGS devices. We review how recent devices have attempted to meet these challenges and give our opinion as to the necessary characteristics for the development of future devices.
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Affiliation(s)
- Richard M H Lee
- Chelsea and Westminster Hospital NHS Foundation Trust, London, UK.,NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Yann Bouremel
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
| | - Ian Eames
- UCL Department of Mechanical Engineering, London, UK
| | - Steve Brocchini
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK.,UCL School of Pharmacy, London, UK
| | - Peng Tee Khaw
- NIHR Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK
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Yadav KS, Sharma S. Implantable drainage devices in glaucoma: Quo vadis? Eur J Pharm Sci 2019; 133:1-7. [DOI: 10.1016/j.ejps.2019.03.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2018] [Revised: 02/28/2019] [Accepted: 03/10/2019] [Indexed: 10/27/2022]
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Greene CA, Misra SL, Lee H, McKelvie J, Kapadia K, McFarlane R, McGhee CNJ, Green CR, Sherwin T. The Sheep Cornea: Structural and Clinical Characteristics. Curr Eye Res 2018; 43:1432-1438. [PMID: 30136872 DOI: 10.1080/02713683.2018.1510970] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
PURPOSE The aim of this study was to perform qualitative and quantitative analyses to characterize the corneas of young, healthy sheep. MATERIALS AND METHODS Eight healthy male sheep, 10 months to 1 year of age, were included as experimental subjects. Central corneal thickness was measured using a handheld pachymeter, and an Easygraph corneal topographer provided topographic maps. Microstructural imaging of corneal layers was achieved by using the Heidelberg Retina Tomograph III Rostock Corneal Module in vivo corneal microscope (IVCM). An Ocular Response Analyzer (ORA) provided quantitative measurements of intraocular pressure (IOP), corneal hysteresis (CH), and corneal resistance factor. Tissue histology and immunohistochemistry were carried out to obtain detail on the corneal layers. RESULTS Light microscopy and immunohistochemical labeling revealed a stratified epithelium, a limbus with numerous limbal crypts, a thick basement membrane, a thin Bowman's layer, a thick corneal stroma with a dense population of keratocytes, and a thick, hyper-reflective Descemet's membrane. Using IVCM, the cell density of the basal layer was noted to be significantly higher than that of other epithelial cell types. The density of keratocytes was significantly higher (P value = 0.0223) in the anterior compared to the posterior stroma. The endothelial cells were organized in a characteristic honeycomb pattern. The mean and standard deviation values for central corneal pachymetry were 623.14 ± 19.5 μm and 616.37 ± 34.87 μm for the left and right eyes, respectively. ORA-derived mean values for IOPcc and CH for the left and right eyes were 14.93 ± 1.73 mm Hg and 15.16 ± 2.02 mm Hg and 3.56 ± 0.72 mm Hg and 3.73 ± 0.49 mm Hg, respectively. CONCLUSIONS The anatomical and clinical characteristics of the sheep cornea, as outlined in this study, make the sheep a suitable and relevant model for corneal research. This study provides researchers with important data on the suitability of sheep as a model for ophthalmic experiments.
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Affiliation(s)
- Carol Ann Greene
- a The University of Auckland, Department of Ophthalmology , New Zealand National Eye Centre , Auckland , New Zealand
| | - Stuti Lonie Misra
- a The University of Auckland, Department of Ophthalmology , New Zealand National Eye Centre , Auckland , New Zealand
| | - Hannah Lee
- b Department of Wine, Food and Molecular Biosciences , Lincoln University , Canterbury , New Zealand
| | - James McKelvie
- a The University of Auckland, Department of Ophthalmology , New Zealand National Eye Centre , Auckland , New Zealand
| | - Kushant Kapadia
- a The University of Auckland, Department of Ophthalmology , New Zealand National Eye Centre , Auckland , New Zealand
| | - Robin McFarlane
- b Department of Wine, Food and Molecular Biosciences , Lincoln University , Canterbury , New Zealand
| | - Charles Ninian John McGhee
- a The University of Auckland, Department of Ophthalmology , New Zealand National Eye Centre , Auckland , New Zealand
| | - Colin Richard Green
- a The University of Auckland, Department of Ophthalmology , New Zealand National Eye Centre , Auckland , New Zealand
| | - Trevor Sherwin
- a The University of Auckland, Department of Ophthalmology , New Zealand National Eye Centre , Auckland , New Zealand
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Sharif NA. iDrugs and iDevices Discovery Research: Preclinical Assays, Techniques, and Animal Model Studies for Ocular Hypotensives and Neuroprotectants. J Ocul Pharmacol Ther 2018; 34:7-39. [PMID: 29323613 DOI: 10.1089/jop.2017.0125] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Discovery ophthalmic research is centered around delineating the molecular and cellular basis of ocular diseases and finding and exploiting molecular and genetic pathways associated with them. From such studies it is possible to determine suitable intervention points to address the disease process and hopefully to discover therapeutics to treat them. An investigational new drug (IND) filing for a new small-molecule drug, peptide, antibody, genetic treatment, or a device with global health authorities requires a number of preclinical studies to provide necessary safety and efficacy data. Specific regulatory elements needed for such IND-enabling studies are beyond the scope of this article. However, to enhance the overall data packages for such entities and permit high-quality foundation-building publications for medical affairs, additional research and development studies are always desirable. This review aims to provide examples of some target localization/verification, ocular drug discovery processes, and mechanistic and portfolio-enhancing exploratory investigations for candidate drugs and devices for the treatment of ocular hypertension and glaucomatous optic neuropathy (neurodegeneration of retinal ganglion cells and their axons). Examples of compound screening assays, use of various technologies and techniques, deployment of animal models, and data obtained from such studies are also presented.
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Affiliation(s)
- Najam A Sharif
- 1 Global Alliances & External Research , Santen Incorporated, Emeryville, California.,2 Department of Pharmaceutical Sciences, Texas Southern University , Houston, Texas.,3 Department of Pharmacology and Neuroscience, University of North Texas Health Sciences Center , Fort Worth, Texas
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Batlle JF, Fantes F, Riss I, Pinchuk L, Alburquerque R, Kato YP, Arrieta E, Peralta AC, Palmberg P, Parrish RK 2nd, Weber BA, Parel JM. Three-Year Follow-up of a Novel Aqueous Humor MicroShunt. J Glaucoma 2016; 25:e58-65. [PMID: 26766400 DOI: 10.1097/IJG.0000000000000368] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS An observational study to determine the safety and efficacy of filtering surgery employing a microlumen aqueous drainage device (InnFocus MicroShunt), used intraoperatively with Mitomycin C, implanted alone or in combination with phacoemulsification. MATERIALS AND METHODS Single-site, prospective, nonrandomized study of 23 eyes that had failed maximum tolerated glaucoma medication, followed for 3 years. A MicroShunt was implanted ab externo through a needle tract under the limbus, draining aqueous from the anterior chamber to the scleral surface. Prespecified outcome measures include: intraocular pressure (IOP) control, with and without supplemental medication, success rate, medication use, and adverse events. RESULTS Fourteen patients received the MicroShunt alone and 9 with cataract surgery. At 1 (n=23), 2 (n=22), and 3 (n=22) years of follow-up; the qualified success rate (IOP ≤ 14 mm Hg and IOP reduction ≥ 20%) was 100%, 91%, and 95%; mean medicated IOP was reduced from 23.8 ± 5.3 to 10.7 ± 2.8, 11.9 ± 3.7, and 10.7 ± 3.5 mm Hg, and the mean number of glaucoma medications/patient was reduced from 2.4 ± 0.9 to 0.3 ± 0.8, 0.4 ± 1.0, and 0.7 ± 1.1, respectively. The most common complications were transient hypotony (13%, 3/23) and transient choroidal effusion (8.7%, 2/23), all resolved spontaneously. There were no leaks, infections, migrations, erosions, persistent corneal edema, or serious long-term adverse events. CONCLUSION Surgery with the InnFocus MicroShunt transscleral aqueous drainage tube with Mitomycin C achieved IOP control in the low teens in most subjects up to 3 years of follow-up with only transient adverse events occurring within the first 3 months after surgery.
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Pinchuk L, Riss I, Batlle JF, Kato YP, Martin JB, Arrieta E, Palmberg P, Parrish RK, Weber BA, Kwon Y, Parel JM. The use of poly(styrene-block-isobutylene-block-styrene) as a microshunt to treat glaucoma. Regen Biomater 2016; 3:137-42. [PMID: 27047682 PMCID: PMC4817329 DOI: 10.1093/rb/rbw005] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2015] [Accepted: 01/04/2016] [Indexed: 11/13/2022] Open
Abstract
The InnFocus MicroShunt® is a minimally invasive glaucoma drainage microtube used to shunt aqueous humor from the anterior chamber of the eye to a flap formed under the conjunctiva and Tenon’s capsule. The safety and clinical performance of this device approaches that of trabeculectomy with mitomycin C, the current ‘gold standard’ treatment for advanced glaucoma. The invention of a new biomaterial called poly(styrene-block-isobutylene-block-styrene) or ‘SIBS’ is the enabling factor which led to the success of this product. SIBS is ultrastable with virtually no foreign body reaction in the body, which manifests as clinically insignificant inflammation and capsule formation in the eye. The lack of capsule formation enables unobstructed flow through the 70 µm lumen tube and the achievement of controlled low intraocular pressure, which is important for the management of glaucoma. This article summarizes the integration of SIBS into a glaucoma drainage device and confirms its functionality with clinical success over a 2-year period.
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Affiliation(s)
- Leonard Pinchuk
- InnFocus, Inc., Miami, FL, USA;; Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Isabelle Riss
- Pôle Ophtalmologique De La Clinique Mutualiste, Pessac Cedex, France
| | | | | | | | - Esdras Arrieta
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Paul Palmberg
- Anne Bates Leach Eye Hospital, University of Miami, Bascom Palmer Eye Institute, Miller School of Medicine, Miami, FL, USA and
| | - Richard K Parrish
- Anne Bates Leach Eye Hospital, University of Miami, Bascom Palmer Eye Institute, Miller School of Medicine, Miami, FL, USA and
| | | | | | - Jean-Marie Parel
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, FL, USA;; Department of Ophthalmology, University of Paris Hotel-Dieu Hospital, Paris, France
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Pinchuk L, Riss I, Batlle JF, Kato YP, Martin JB, Arrieta E, Palmberg P, Parrish RK, Weber BA, Kwon Y, Parel JM. The development of a micro-shunt made from poly(styrene-block-isobutylene-block-styrene) to treat glaucoma. J Biomed Mater Res B Appl Biomater 2015; 105:211-221. [PMID: 26380916 PMCID: PMC5215625 DOI: 10.1002/jbm.b.33525] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2015] [Accepted: 08/14/2015] [Indexed: 11/08/2022]
Abstract
Glaucoma is the second leading cause of blindness with ∼70 million people worldwide who are blind from this disease. The currently practiced trabeculectomy surgery, the gold standard treatment used to stop the progression of vision loss, is rather draconian, traumatic to the patient and requires much surgical skill to perform. This article summarizes the more than 10‐year development path of a novel device called the InnFocus MicroShunt®, which is a minimally invasive glaucoma drainage micro‐tube used to shunt aqueous humor from the anterior chamber of the eye to a flap formed under the conjunctiva and Tenon's Capsule. The safety and clinical performance of this device approaches that of trabeculectomy. The impetus to develop this device stemmed from the invention of a new biomaterial called poly(styrene‐block‐isobutylene‐block‐styrene), or “SIBS.” SIBS is ultra‐stable with virtually no foreign body reaction in the body, which manifests in the eye as clinically insignificant inflammation and capsule formation. The quest for an easier, safer, and more effective method of treating glaucoma led to the marriage of SIBS with this glaucoma drainage micro‐tube. This article summarizes the development of SIBS and the subsequent three iterations of design and four clinical trials that drove the one‐year qualified success rate of the device from 43% to 100%. © 2015 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 211–221, 2017.
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Affiliation(s)
- Leonard Pinchuk
- InnFocus, Inc., Miami, Florida.,Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Isabelle Riss
- Pôle Ophtalmologique de la Clinique Mutualiste, Pessac, Cedex, France
| | | | | | | | - Esdras Arrieta
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Paul Palmberg
- Anne Bates Leach Eye Hospital, Miami, Florida.,Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | - Richard K Parrish
- Anne Bates Leach Eye Hospital, Miami, Florida.,Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida
| | | | | | - Jean-Marie Parel
- Ophthalmic Biophysics Center, Bascom Palmer Eye Institute, University of Miami Miller School of Medicine, Miami, Florida.,Department of Ophthalmology, University of Paris Hotel-Dieu Hospital, Paris, France
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Abstract
There is general consensus that surgery gives a better intraocular pressure (IOP) control than medical therapy, but surgery may be affected by complications and failures, and for this reason nowadays, it is reserved to advanced or clearly progressive glaucoma. In recent years, there have been a lot of efforts to enhance safety and efficacy of conventional surgery as to find new techniques more safer and more effective. Actually, this is a field in rapid evolution, and we have a great number of innovative procedures, often working on complete different basis. These procedures are classified according to their mechanism of action and the type of surgical approach, in order to clearly understand of what we are speaking about. From a general point of view, surgical procedures may be divided in procedures that increase outflow and procedures that reduce aqueous production: most of these procedures can be performed with an ab externo or an ab interno approach. The ab interno approach has great advantages and enormous potential of development; probably, its diffusion will be facilitated by the development of new devices for angle visualization. Nevertheless, it is important to remember that actually none of the new procedures has been validated in large controlled clinical trials and none of the new procedures is indicated when IOP target is very low.
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Affiliation(s)
- Marco Nardi
- Ophthalmology Unit, University of Pisa, Pisa, Italy.
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Abstract
We are currently in the midst of a surge in interest in glaucoma surgery. Novel pathways for reducing intraocular pressure (IOP) have been tried with various levels of success over the last few years. While the trabecular bypass and suprachoroidal approaches have captured much of the attention, filtering aqueous into the sub-conjunctival space remains the gold standard for lowering IOP. This review attempts to focus on current research in surgical methods to enhance filtration by potentially improving on tried and tested methods like the trabeculectomy, deep sclerectomy, and tube surgeries.
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Affiliation(s)
- Tarek Shaarawy
- Department of Ophthalmology, Geneva University Hospitals, Geneva, Switzerland
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45
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Wu W, Karamdoust S, Turowec BA, Gillies ER. Synthesis and application of cinnamate-functionalized rubber for the preparation of UV-curable films. Eur Polym J 2013. [DOI: 10.1016/j.eurpolymj.2013.10.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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46
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Abd Rabo Moustafa MM, Gillies ER. Rubber Functionalization by Diels–Alder Chemistry: From Cross-Linking to Multifunctional Graft Copolymer Synthesis. Macromolecules 2013. [DOI: 10.1021/ma401087v] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
| | - Elizabeth R. Gillies
- Department of Chemistry, The University of Western Ontario, 1151 Richmond St.,
London, Canada, N6A 5B7
- Department
of Chemical and Biochemical
Engineering, The University of Western Ontario, 1151 Richmond St., London, Canada, N6A 5B9
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47
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Abstract
Purpose To evaluate to what extent contemporary glaucoma abstracts offer complete information and to suggest a new manner of pressure results reporting. Materials, methods, and results Most of the 36 relevant surgical glaucoma abstracts found in one issue of International Glaucoma Review contain insufficient data-supported statements. Such abstracts cannot offer a clear picture of the study essence if economic, linguistic, or political barriers prevent access to the full text. In order to enrich abstract content and to avoid typographic space waste, a formula is suggested to provide, in one single line of symbols and figures, all the necessary data for statistical interpretation at two evolution moments: the first significative control (6 months) and the final one. Conclusion The current manner of results reporting in surgical glaucoma abstracts is subject to too little standardization, allowing insufficiently data-supported statements. Abstracts, especially those printed in small-circulation language journals, should be conceived and standardized in such a manner that any abstract review reader is capable of grasping the essence of the study at first glance. The suggested manner of reporting results would bring satisfaction to all areas of the process. Publishers would save typographic space, readers would find all the necessary data for statistical analysis and comparison with other studies, and authors would be convinced that the essence of their work would penetrate in spite of any economic, linguistic, or political barriers.
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48
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Arrieta EA, Aly M, Parrish R, Dubovy S, Pinchuk L, Kato Y, Fantes F, Parel JM. Clinicopathologic correlations of poly-(styrene-b-isobutylene-b-styrene) glaucoma drainage devices of different internal diameters in rabbits. Ophthalmic Surg Lasers Imaging Retina 2011; 42:338-45. [PMID: 21800806 DOI: 10.3928/15428877-20110603-01] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Accepted: 03/24/2011] [Indexed: 11/20/2022]
Abstract
BACKGROUND AND OBJECTIVE To assess the biocompatibility and intraocular pressure (IOP) lowering effect of a novel glaucoma drainage implant in rabbits. MATERIALS AND METHODS Sixteen New Zealand white rabbits received one of three glaucoma drainage implants fabricated from poly-(styrene-b-isobutylene-b-styrene [SIBS]) with an internal diameter of the lumen of either 70 (6 eyes), 100 (6 eyes), or 150 (4 eyes) μm. Clinical follow-up examinations were performed during 6 months and postmortem eyes were studied with light microscopy. RESULTS Smaller internal diameter implants were associated with fewer complications. IOP levels were not statistically different among the groups. No eyes developed serious complications. Mild chronic inflammation was observed around the tube using light microscopy. CONCLUSION SIBS glaucoma drainage implants did not produce clinically detectable intraocular inflammation in a rabbit model. The 70- and 100-μm SIBS drainage devices demonstrated fewer postoperative complications. IOP levels were not statistically different from control eyes in all groups.
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Affiliation(s)
- Esdras A Arrieta
- Ophthalmic Biophysics Center, University of Miami Miller School of Medicine, Miami, Florida 33136, USA.
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49
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Bonduelle CV, Karamdoust S, Gillies ER. Synthesis and Assembly of Butyl Rubber–Poly(ethylene oxide) Graft Copolymers: From Surface Patterning to Resistance to Protein Adsorption. Macromolecules 2011. [DOI: 10.1021/ma2009996] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Colin V. Bonduelle
- Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Canada, N6A 5B7
| | - Solmaz Karamdoust
- Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Canada, N6A 5B7
| | - Elizabeth R. Gillies
- Department of Chemistry, The University of Western Ontario, 1151 Richmond Street, London, Canada, N6A 5B7
- Department of Chemical and Biochemical Engineering, The University of Western Ontario, 1151 Richmond St., London, Canada, N6A 5B9
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50
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Leszczynski R, Stodolak E, Wieczorek J, Orlowska-Heitzman J, Gumula T, Blazewicz S. In vivo biocompatibility assessment of (PTFE-PVDF-PP) terpolymer-based membrane with potential application for glaucoma treatment. J Mater Sci Mater Med 2010; 21:2843-2851. [PMID: 20652824 PMCID: PMC2962782 DOI: 10.1007/s10856-010-4132-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/11/2010] [Accepted: 07/12/2010] [Indexed: 05/29/2023]
Abstract
The aim of the work was to evaluate the in vivo biological behaviour of polymeric membrane materials for glaucoma implants. The base material was biostable synthetic terpolymer (PTFE-PVDF-PP) with proved biocompability (PN-EN ISO 10993). The samples manufactured in the form a membrane were subjected to chemical and physical treatment to create an open pore system within the polymer matrix. As a porogenic phase biodegradable natrium alginate in a fibrous form was employed. The non-perforating deep sclerectomy technique was performed in a rabbit model. The clinical observations were made after 14 and 30 days. During the study clinical symptoms of a moderate degree were observed, and histopathological changes were typical for foreign body implantation. At the end stage of the study no significant difference in histopathological assessment was found between control and experimental group. Similarities observed in both groups and relatively mild histopathological changes in the tissue surrounding the implant indicate that the observed symptoms come from a deep scleral trauma caused by surgery, and not by the presence of the implant itself.
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Affiliation(s)
- Rafał Leszczynski
- Department of Ophthalmology, Medical University of Silesia, Katowice, Poland
| | - Ewa Stodolak
- Department of Biomaterials, Faculty of Materials Science and Ceramics, University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland
| | - Jarosław Wieczorek
- Department of Biotechnology of Animal Reproduction, National Research Institute of Animal Production, Balice, Poland
| | | | - Teresa Gumula
- Department of Biomaterials, Faculty of Materials Science and Ceramics, University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland
| | - Stanislaw Blazewicz
- Department of Biomaterials, Faculty of Materials Science and Ceramics, University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland
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