In Vivo Testing of a Novel Adjustable Glaucoma Drainage Device

Villamarin, Adan; Stergiopulos, Nikolaos; Bigler, Stéphane; Mermoud, André; Moulin, Alexandre; Roy, Sylvain

doi:10.1167/iovs.14-14563

Cited by 15 publications

(12 citation statements)

References 18 publications

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“…Moreover, the valve had passed a previous in vitro fatigue test with 100 000 switching cycles of the valve. Hence, the present study and previous ones show that magnetic adjustment of valves in GDDs [18, 30] and other microfluidic devices [36] seems to work well. However, the results of the present implant do not provide evidence for the longstanding in vivo function of the valve opening of the implant under the conjunctival flap.…”

Section: Discussionsupporting

confidence: 82%

“…Statistically significant differences between the IOP of the operated eye and the control eye were detectable for two (group B) and seven (group A) days, respectively. Villamarin et al reported a longer period of statistically significant IOP differences between both eyes in seven healthy rabbits after implantation of a functionally closed GDD, lasting eight days [30]. Consequently, the decreased pressures in the present study seemed to be within the normal time range in healthy rabbits.…”

Section: Discussionsupporting

confidence: 48%

“…In the present study, New Zealand White rabbits, considered as an established animal model for ophthalmic studies [23, 28–30], were chosen. Since the anatomy of rabbit eyes [31, 32] and conjunctiva [33] are similar to those in humans, the practicable and rapid positioning of the present implant, enabling the opening of the anterior eye chamber, are probably feasible in humans.…”

Section: Discussionmentioning

confidence: 99%

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Comparison of two prototypes of a magnetically adjustable glaucoma implant in rabbits

et al. 2019

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Glaucoma drainage devices are used in surgical glaucoma therapy. Success of controlling the intraocular pressure is limited due to fibrous implant encapsulation and fibrin coating on the implant which lead to drainage obstructions. An innovative implant with a magnetically adjustable valve was developed. The valve opening of the implant should eliminate inflammatory products from the outflow area and affect fibrous tissue formation to achieve a sufficient long-term aqueous humour outflow. Lifting of this valve should disturb cell adhesion by exerting mechanical forces. Before testing this hypothesis, the flow characteristics of glaucoma drainage devices, especially the outflow resistance by regular IOP, should be considered in a pilot study, as they are important in preventing too low postoperative intraocular pressure known as ocular hypotony. Therefore, two prototypes of the innovative implant differing in their valve area design were examined regarding their flow characteristics in a limited animal experiment lasting two weeks. Ten healthy New Zealand White rabbits were divided into two groups (A & B) with different implanted prototypes. Daily, tonometry and direct ophthalmoscopy were performed to assess the intraocular pressure and the inflammatory reaction of the eye. After two weeks, the rabbits were euthanised to evaluate the initially histological inflammatory reaction to the implant. In group A, one case of hypotony emerged. When considering the entire observation period, a highly statistically significant difference between the intraocular pressure in the operated eye and that in the control eye was detected in group A (p < 0.0001) in contrast to group B (p = 0.0063). The postoperative inflammatory signs decreased within two weeks. Histologically, a typical but low level foreign body reaction with macrophages and lymphocytes as well as mild to moderate fibrosis was seen after the short experimental period. Based on our tonometric results, prototype B seems to be the system of choice for further research assessing its long-term function and biocompatibility.

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Section: Discussionsupporting

confidence: 82%

Section: Discussionsupporting

confidence: 48%

Section: Discussionmentioning

confidence: 99%

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Comparison of two prototypes of a magnetically adjustable glaucoma implant in rabbits

et al. 2019

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“…The eyeWatch™ has been described by Villamarin et al and validated in vitro and in vivo . 3 , 4 Within the mechanism, an eccentrically shaped magnetic disk can be rotated by an externally controlled magnet unit to adjust fluidic resistance. A customized adjustment of aqueous humor outflow can thus be achieved to minimize the risk of hypotony or inadequate lowering of IOP.…”

Section: Discussionmentioning

confidence: 99%

eyeWatch™ System Combined with Non-plated Intraorbital Tube Insertion for the Management of Refractory Glaucoma: A Case Series

Detorakis¹,

Villamarin²,

Roy³

et al. 2020

Journal of Current Glaucoma Practice

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A bstract Introduction The eyeWatch™ is a novel device in glaucoma surgery aiming at the control of aqueous flow through the use of an external magnetic control unit. We propose the modification of this approach through the use of an injectable perforated tube rather than a plated valve. Materials and methods Procedures were performed at the Department of Ophthalmology of the University of Crete. Three blind painful eyes of three patients were included. All patients were operated under topical anesthesia. A purpose designed blunt-ended injector was used to insert intraorbitally a perforated 4 cm-long silicone tube. The tube was then connected to an eyeWatch™ device which was placed in a standard fashion along the superior–temporal quadrant of the eyeball. The procedure was uneventful in cases I and II, whereas in case III the tube had to be trimmed by 1.5 cm because of cicatricial changes in the orbit. The eyeWatch™ was left closed (position VI) at the conclusion of surgeries. Patients were examined on the 1-day, 1-week, 2-week, 1-month, 3-month, and 6-month intervals and in one case on the 12-month interval. Results No major complications were observed. The intraocular pressure (IOP) remained under 15 mm Hg without anti-glaucomatous medications in all postoperative intervals in cases I and 2 with readjustment of eyeWatch™ at position IV. In case III, despite the change of the eyeWatch™ to the open position, the IOP remained high (40 mm Hg). Discussion The combination of the eyeWatch™ with an insertable perforated tube instead of a standard non-valved plate may prove a valid minimally invasive option. Modifications of the technique, such as an increased number and diameter of tube perforations, increased inserted tube length, perhaps aided by a sharp-ended injector, and selection of the insertion quadrant, may increase the effectiveness of the method. Clinical significance eyeWatch™ combined with a single tube instead of a plated valve is a feasible, quick, and minimally invasive technique that can be used in glaucoma surgery. How to cite this article Detorakis ET, Villamarin A, Roy S, et al. eyeWatch™ System Combined with Non-plated Intraorbital Tube Insertion for the Management of Refractory Glaucoma: A Case Series. J Curr Glaucoma Pract 2020;14(2):64–67.

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“…Bei uns sind diese Eingriffe jedoch immer noch deutlich seltener als eine konventionelle filtrierende Operation. Neuere Entwicklungen wie ein regulierbares Ventil zur Vermeidung einer Überfiltration im unmittelbar postoperativen Verlauf [63] oder sogar die Kombination eines Tubes mit einem MIGS-Stent [64] könnten die Methode sicherer machen und damit die Indikationen erweitern.…”

Section: Alternative Operationsverfahrenunclassified

Operieren wir die Glaukome zu spät?

Stürmer

Faschinger

2017

Klin Monatsbl Augenheilkd

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As glaucoma specialists, we often ask ourselves why patients are referred so late for surgery. Usually the patient is referred in a far advanced stage of the disease after long-term conventional treatment with topical medications. By that time, substantial morphologic damage is present and the patient is disabled by far advanced visual field defects. In addition, decompensated intraocular pressure, despite maximal tolerated medical treatment, is seen. Delayed surgery due to late diagnosis is rather a rare event. Various reasons may be responsible for this late referral. Improved IOP-lowering medications (i.e., fixed combinations), personal aversion (fear and knowledge of lack of improvement in visual acuity) against surgery, and imperfect glaucoma procedures may play an important role. A retrospective review of the last 274 cases referred for filtering glaucoma surgery is used to describe and analyze criteria for adequate timing of glaucoma surgery. This study reveals that almost ¾ of patients are referred rather late for glaucoma surgery. Criteria for adequate timing of glaucoma surgery are given for non-glaucoma specialists in particular. They apply for all types of glaucoma surgery, and the pros and cons are discussed in detail. Trabeculectomy is still regarded as the gold standard of glaucoma surgery. Because trabeculectomy may not be an ideal glaucoma procedure, there is hope that the modern less-invasive glaucoma procedures (MIGS) will be able to extend indications for glaucoma surgery. This may also lower the hurdle of referral for glaucoma surgery for both patients and non-glaucoma specialist doctors.

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In Vivo Testing of a Novel Adjustable Glaucoma Drainage Device

Abstract: Implanting the AGDD is a safe and uncomplicated surgical procedure. The fluidic resistance was noninvasively adjustable during the postoperative period with the AGDD between its fully closed and fully open positions.

Cited by 15 publications

References 18 publications

Comparison of two prototypes of a magnetically adjustable glaucoma implant in rabbits

Comparison of two prototypes of a magnetically adjustable glaucoma implant in rabbits

eyeWatch™ System Combined with Non-plated Intraorbital Tube Insertion for the Management of Refractory Glaucoma: A Case Series

Operieren wir die Glaukome zu spät?

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In Vivo Testing of a Novel Adjustable Glaucoma Drainage Device

Abstract: Implanting the AGDD is a safe and uncomplicated surgical procedure. The fluidic resistance was noninvasively adjustable during the postoperative period with the AGDD between its fully closed and fully open positions.

Cited by 15 publications

References 18 publications

Comparison of two prototypes of a magnetically adjustable glaucoma implant in rabbits

Comparison of two prototypes of a magnetically adjustable glaucoma implant in rabbits

eyeWatch&trade; System Combined with Non-plated Intraorbital Tube Insertion for the Management of Refractory Glaucoma: A Case Series

Operieren wir die Glaukome zu spät?

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Product

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eyeWatch™ System Combined with Non-plated Intraorbital Tube Insertion for the Management of Refractory Glaucoma: A Case Series