scholarly journals Magnetically Actuated Glaucoma Drainage Device with Adjustable Flow Properties after Implantation

2021 ◽  
Vol 4 (1) ◽  
pp. 3
Author(s):  
Inês C. F. Pereira ◽  
Hans M. Wyss ◽  
Henny J. M. Beckers ◽  
Jaap M. J. den Toonder
Keyword(s):  
Aqueous Humor ◽  
Alternative Pathway ◽  
Glaucoma Surgery ◽  
Glaucoma Drainage Device ◽  
Hydrodynamic Resistance ◽  
Aqueous Humor Outflow ◽  
Non Invasive ◽  
Magnetically Actuated ◽  
Magnetic Stimulus ◽  
Glaucoma Drainage Devices

Glaucoma is the second leading cause of preventable blindness worldwide, following cataract formation. A rise in the intraocular pressure (IOP) is a major risk factor for this disease, and results from an elevated resistance to aqueous humor outflow from the anterior chamber of the eye. Glaucoma drainage devices provide an alternative pathway through which the aqueous humor can effectively exit the eye, thereby lowering the IOP. However, post-operative IOP is unpredictable and current implants are deficient in maintaining IOP at optimal levels. To address this deficiency, we are developing an innovative, non-invasive magnetically actuated glaucoma implant with a hydrodynamic resistance that can be adjusted following surgery. This adjustment is achieved by integrating a magnetically actuated microvalve into the implant, which can open or close fluidic channels using an external magnetic stimulus. This microvalve was fabricated from poly(styrene–block–isobutylene–block–styrene), or ‘SIBS’, containing homogeneously dispersed magnetic microparticles. “Micro-pencil” valves of this material were fabricated using a combination of femtosecond laser machining with hot embossing. The glaucoma implant is comprised of a drainage tube and a housing element fabricated from two thermally bonded SIBS layers with the microvalve positioned in between. Microfluidic experiments involving actuating the magnetic micro-pencil with a moving external magnet confirmed the valving function. A pressure difference of around 6 mmHg was achieved, which is sufficient to overcome hypotony (i.e., too low IOP)—one of the most common post-operative complications following glaucoma surgery.

scholarly journals Conventional glaucoma implants and the new MIGS devices: a comprehensive review of current options and future directions

Eye ◽  
2021 ◽  
Author(s):  
Inês C. F. Pereira ◽  
Rosanne van de Wijdeven ◽  
Hans M. Wyss ◽  
Henny J. M. Beckers ◽  
Jaap M. J. den Toonder
Keyword(s):  
Anterior Chamber ◽  
Aqueous Humour ◽  
Alternative Pathway ◽  
Glaucoma Surgery ◽  
Future Directions ◽  
Plate Design ◽  
Glaucoma Drainage Devices ◽  
Abnormal Increase ◽  
Preventable Blindness ◽  
Glaucoma Implants

AbstractGlaucoma 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.

MRI after successful eyeWatchTM implantation

2020 ◽  
pp. 112067212097361
Author(s):  
Sylvain Roy ◽  
Adan Villamarin ◽  
Nikolaos Stergiopulos ◽  
André Mermoud
Keyword(s):  
Magnetic Field ◽  
Control Unit ◽  
Glaucoma Surgery ◽  
Glaucoma Drainage Device ◽  
Aqueous Humor Outflow ◽  
Cerebral Mri ◽  
Adjustable Mechanism ◽  
The Stability ◽  
Persistent Headache

The eyeWatchTM is a new glaucoma drainage device that includes an adjustable mechanism that can vary the resistance to aqueous humor outflow during the postoperative period to reduce the burden of postoperative intraocular pressure (IOP) management. The mechanism contains a magnetic rotor that can be adjusted using an external magnetic control unit. Adjustments of the position of the rotor are performed mostly in the initial postoperative follow-up period in order to reach the target IOP. However, for some patients, it might be necessary to perform MRI for the sake of medical investigations. As the MRI is creating a strong magnetic field, this magnetic field is likely to interact with the adjustable rotor of the eyeWatchTM, resulting in modification of the IOP. We report the case of an 82-old female patient successfully operated with the implantation of an eyeWatchTM. The patient underwent a cerebral MRI for persistent headache. Shortly after the MRI procedure, the patient was checked at the eye clinic to assess the position of the rotor and to measure the IOP. The eyeWatchTM was readjusted to the former position set before undergoing the MRI. No complications were reported in the follow-up after MRI. This case demonstrates that MRI examinations can be safely performed after glaucoma surgery using an eyeWatchTM without compromising on the quality of the imaging or the stability of the IOP. This is a complication-free procedure that only requires checking the new position of the rotor and re-adjusting the implant, if necessary, to achieve the target IOP.

scholarly journals Bleb-Independent Glaucoma Surgery to Activate the Uveolymphatic Route of Non-Trabecular Aqueous Humor Outflow: Short-Term Clinical and OCT Results

Vision ◽  
2022 ◽  
Vol 6 (1) ◽  
pp. 4
Author(s):  
Vinod Kumar ◽  
Kamal Abdulmuhsen Abu Zaalan ◽  
Andrey Igorevich Bezzabotnov ◽  
Galina Nikolaevna Dushina ◽  
Ahmad Saleh Soliman Shradqa ◽  
...  
Keyword(s):  
Aqueous Humor ◽  
Distal Part ◽  
Lymphatic Vessels ◽  
Glaucoma Surgery ◽  
Proximal Part ◽  
Deep Sclerectomy ◽  
Aqueous Humor Outflow ◽  
Collagen Implant ◽  
The Mean ◽  
Partial Success

The deep sclerectomy technique was modified to enhance aqueous humor (AH) outflow via the non-trabecular pathway. A pilot study was carried out to assess its safety and effectiveness. Thirty-eight patients were under observation. After superficial scleral flap (4 × 4 mm), deep scleral layers were divided into three parts by three parallel-to-limbus incisions. Deep sclerectomy without creating a window in the Descemetes’ membrane was carried out in the distal part. A collagen implant was placed under the sclera of the remaining two parts with one end in the intrascleral pool. The third proximal part was excised to expose the uvea and implant. A Nd:YAG laser trabeculotomy at the surgery site was made on postoperative days 7–10. Outcome measures were IOP change, use of hypotensive medication(s), complications, and the need for a second surgery. At six months, the mean IOP decreased from 29.1 ± 9.2 mm Hg to 14.0 ± 4.3 mm Hg (p = 1.4 × 10−9); hypotensive medication use reduced from 2.9 ± 0.9 to 0.6 ± 1.0 (p = 1.3 × 10−10); complete success was achieved in 68.4% of cases and partial success was achieved in 31.6% of cases. Intraoperative and postoperative complications were rare and manageable. The OCT of the surgery site revealed the absence of bleb in all cases. Lymphatic vessels with characteristic bicuspid valves in their lumen were detected in conjunctiva near the operation site and over it in 32 patients. IOP decrease in the proposed technique was achieved by activation of the uveolymphatic route of AH outflow.

scholarly journals Combined pars plana glaucoma drainage device placement and vitrectomy using a vitrectomy sclerotomy site for tube placement: a case series

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Enchi Kristina Chang ◽  
Sanchay Gupta ◽  
Marika Chachanidze ◽  
John B. Miller ◽  
Ta Chen Chang ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Pars Plana Vitrectomy ◽  
Case Series ◽  
Tube Placement ◽  
Glaucoma Drainage Device ◽  
Drainage Device ◽  
Glaucoma Drainage Devices ◽  
Pars Plana ◽  
Sclerotomy Site

Abstract Purpose The purpose of this study is to report the safety and efficacy of pars plana glaucoma drainage devices with pars plana vitrectomy using one of the vitrectomy sclerotomy sites for tube placement in patients with refractory glaucoma. Methods Retrospective case series of 28 eyes of 28 patients who underwent combined pars plana glaucoma drainage device and pars plana vitrectomy between November 2016 and September 2019 at Massachusetts Eye and Ear. Main outcome measures were intraocular pressure (IOP), glaucoma medication burden, best corrected visual acuity, and complications. Statistical tests were performed with R and included Kaplan-Meier analyses, Wilcoxon paired signed-rank tests, and Fisher tests. Results Mean IOP decreased from 22.8 mmHg to 11.8 mmHg at 1.5 years (p = 0.002), and mean medication burden decreased from 4.3 to 2.1 at 1.5 years (p = 0.004). Both IOP and medication burden were significantly lower at all follow-up time points. The probability of achieving 5 < IOP ≤ 18 mmHg with at least 20% IOP reduction from preoperative levels was 86.4% at 1 year and 59.8% at 1.5 years. At their last visit, three eyes (10.7%) achieved complete success with IOP reduction as above without medications, and 14 eyes (50.0%) achieved qualified success with medications. Hypotony was observed in 1 eye (3.6%) prior to 3 months postoperatively and 0 eyes after 3 months. Visual acuity was unchanged or improved in 23 eyes (82.1%) at their last follow-up. Two patients had a visual acuity decrease of > 2 lines. Two eyes required subsequent pars plana vitrectomies for tube obstruction, and one eye had transient hypotony. Conclusions The results of pars plana glaucoma drainage device and pars plana vitrectomy using one of the vitrectomy sclerotomy sites for tube placement are promising, resulting in significant IOP and medication-burden reductions through postoperative year 1.5 without additional risk of postoperative complications. Inserting glaucoma drainage devices into an existing vitrectomy sclerotomy site may potentially save surgical time by obviating the need to create another sclerotomy for tube placement and suture one of the vitrectomy ports.

scholarly journals Aqueous Angiography: Real-Time and Physiologic Aqueous Humor Outflow Imaging

PLoS ONE ◽  
2016 ◽  
Vol 11 (1) ◽  
pp. e0147176 ◽  
Author(s):  
Sindhu Saraswathy ◽  
James C. H. Tan ◽  
Fei Yu ◽  
Brian A. Francis ◽  
David R. Hinton ◽  
...  
Keyword(s):  
Real Time ◽  
Aqueous Humor ◽  
Aqueous Humor Outflow

Aqueous Humor Outflow Physiology in NOS3 Knockout Mice

2015 ◽  
Vol 56 (8) ◽  
pp. 4891 ◽  
Author(s):  
Yuan Lei ◽  
Xuejin Zhang ◽  
Maomao Song ◽  
Jihong Wu ◽  
Xinghuai Sun
Keyword(s):  
Aqueous Humor ◽  
Knockout Mice ◽  
Aqueous Humor Outflow

scholarly journals Combined Scleral Flap with Donor Scleral Patch Graft for Anterior Tube Placement in Glaucoma Drainage Device Surgery

2016 ◽  
Vol 2016 ◽  
pp. 1-4
Author(s):  
Jea H. Yu ◽  
Chuck Nguyen ◽  
Esmeralda Gallemore ◽  
Ron P. Gallemore
Keyword(s):  
Open Angle Glaucoma ◽  
Effective Means ◽  
Case Series ◽  
Neovascular Glaucoma ◽  
Tube Placement ◽  
Glaucoma Drainage Device ◽  
Scleral Flap ◽  
Retrospective Case ◽  
Glaucoma Drainage Devices ◽  
Patch Graft

Purpose. To report a new technique for anterior placement of tubes for glaucoma drainage devices to reduce the risk of tube erosions.Methods. Retrospective review of select cases of Ahmed Valve surgery combined with the novel method of a limbal-based scleral flap covered by a scleral patch graft to cover the tube at the entrance through the limbus. Intraoperative and postoperative illustrations are shown to highlight the method of tube placement.Results. In this retrospective case series, 3 patients are presented illustrating the technique. Two had neovascular glaucoma and one had primary open-angle glaucoma (POAG). On average, intraocular pressure was reduced from39±14 mmHg to15±2 mmHg and the number of glaucoma medications was reduced from4±1to 0. Preoperative and most recent visual acuities were hand-motion (HM) and HM, 20/60 and 20/50, and 20/70 and 20/30, respectively.Conclusion. The combination of a limbal-based scleral flap with scleral patch graft to cover the tube with glaucoma drainage devices may be an effective means to reduce erosion and protect against endophthalmitis.

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