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.

scholarly journals Effect of peripheral iridectomy on VEGF-A and TGF-β levels in rabbit aqueous humour

2022 ◽  
Vol 22 (1) ◽  
Author(s):  
Annabel C. Y. Chew ◽  
Li-Fong Seet ◽  
Stephanie W. L. Chu ◽  
Nyein C. Lwin ◽  
Tina T. Wong
Keyword(s):  
Anterior Chamber ◽  
Aqueous Humour ◽  
Glaucoma Surgery ◽  
Filtration Surgery ◽  
Glaucoma Filtration Surgery ◽  
Peripheral Iridectomy ◽  
New Zealand White Rabbits ◽  
The Right ◽  
Tgf Β1 ◽  
Time Point

Abstract Background Peripheral iridectomy (PI), routinely performed during glaucoma filtration surgery, may contribute to scarring. This study aims to determine whether PI alters the concentrations of VEGF-A and TGF-β isoforms in the rabbit aqueous humour. Methods Anterior chamber paracentesis (ACP) was performed in both eyes of six New Zealand white rabbits, with additional surgical PI performed in the right eyes. Eyes were examined on postoperative days (PODs) 1, 7, 30 and 60 by means of the tonopen, slit-lamp biomicroscopy, and bead-based cytokine assays for TGF-β and VEGF-A concentrations in the aqueous humor. Results ACP caused a significant reduction in intraocular pressure (IOP) from mean preoperative 11.47 ± 1.01 mmHg to 5.67 ± 1.63 mmHg on POD 1 while PI did not cause further IOP reduction. Limbal conjunctival vasculature appeared slightly increased on POD 1 in both ACP and PI eyes with PI also causing mild bleeding from damaged iris vessels. Two PI eyes developed fibrinous anterior chamber reaction and/ or peripheral anterior synechiae. Aqueous VEGF-A levels were not significantly different between eyes treated with ACP and PI. Aqueous TGF-β concentrations distributed in the ratio of 4:800:1 for TGF-β1:TGF-β2:TGF-β3 respectively. While aqueous TGF-β2 was not significantly induced by either procedure at any time point, TGF-β1 and TGF-β3 were significantly induced above baseline levels by PI on POD 1. Conclusion PI increases the risk of inflammation. The combined induction of aqueous TGF-β1 and TGF-β3 by PI in glaucoma surgery may impact surgery success in glaucoma subtypes sensitive to these isoforms.

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 Artificial drainage devices for glaucoma surgery: an overview

2012 ◽  
Vol 4 (2) ◽  
pp. 295-302 ◽  
Author(s):  
M Chaudhry ◽  
S Grover ◽  
S Baisakhiya ◽  
A Bajaj ◽  
M S Bhatia
Keyword(s):  
Anterior Chamber ◽  
Alternative Pathway ◽  
Surgical Techniques ◽  
Glaucoma Surgery ◽  
Primary Treatment ◽  
Equatorial Plate ◽  
Refractory Glaucoma ◽  
Artificial Drainage ◽  
End Stage

Artificial drainage devices (ADD) create an alternative pathway for aqueous drainage from the anterior chamber of an eye through a tube to the subconjunctival bleb connected to an equatorial plate under the conjunctiva. The ADDs, both valved and non-valved, are available for end stage or refractory glaucoma. Currently, some of these devices, particularly the Express shunt, are recommended for the primary treatment of glaucoma. In this article, we highlight various ADDs, their indications and contraindications, surgical techniques and associated complications.DOI: http://dx.doi.org/10.3126/nepjoph.v4i2.6547 Nepal J Ophthalmol 2012; 4 (2): 295-302 

The TNF-α level variation in the aqueous humour of the anterior chamber inindividuals with cataract

2020 ◽  
pp. 86-87
Author(s):  
V.S. Shevchenko ◽  
◽  
A.S. Prilutskii ◽  
K.Y. Tkachenko ◽  
◽  
...  
Keyword(s):  
Anterior Chamber ◽  
Aqueous Humour ◽  
Level Variation ◽  
Tnf Α ◽  
Α Level

Актуальность. Фактор некроза опухоли(TNF-α) является провоспалительным цитокином, продуцирующимся макрофагами и многими другими клетками. Данные о вариации концентрацииTNF-α во влаге передней камеры глаза у лиц, не имеющих выраженных воспалительных и аутоиммунных процессов практически единичны. Цель. Исследование диапазона вариации фактора некроза опухоли альфа во влаге передней камеры глаза у пациентов с возрастной катарактой. Материал и методы. Отобраны и обследованы 33 пациента, в возрасте от 47 до 82 лет, госпитализированных для плановой экстракции катаракты не имеющих выраженных сопутствующих воспалительных заболеваний (аутоиммунных, острых инфекционных болезней, обострением хронических заболеваний, глаукомы, перенесенного увеита и др.). Влага передней камеры забиралась при вскрытии передней камеры глаза во время факоэмульсификации катаракты. Исследование TNF-αпроводилось с помощью иммуноферментны хтест-систем, разработанных при участии сотрудников кафедры клинической иммунологии, аллергологии и эндокринологии ГОО ВПО «ДонНМУ им.М. Горького». Вышеуказанные тест-системы характеризует высокая чувствительность (0,5 пикограмм в миллилитре) и хорошая воспроизводимость. Результаты. При исследовании уровня TNF-αво влаге передней камеры глаза у пациентов с возрастной катарактой, мы выявили колебания данного показателя от 0 до 2,49 пкг/мл. Следует отметить, что полученные нами результаты показывают небольшую вариацию (в пределах низких значений) данного провоспалительного цитокина в исследованной жидкости у пациентов в возрасте от 47 до80 лет, не имеющих выраженной воспалительной(аутоиммунной и др.) патологии. Выводы. Показана низкая вариация TNF-α во влаге передней камеры глаза у пациентов с возрастной катарактой (у обследуемых исключена сопутствующая выраженная воспалительная патология). Результаты можно также использовать как контрольные при проведении сравнительныхисследований этого цитокина в данной среде у лицс различными заболеваниями глаза.

Short-term anterior chamber inflammation in phacoemulsification with and without Ex-Press glaucoma implant

2019 ◽  
Vol 30 (3) ◽  
pp. 533-537
Author(s):  
Shmuel Graffi ◽  
Beatrice Tiosano ◽  
Modi Naftali ◽  
Nakhoul Nakhoul ◽  
Michael Mimouni ◽  
...  
Keyword(s):  
Visual Acuity ◽  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Medical Center ◽  
Glaucoma Surgery ◽  
Consecutive Series ◽  
Device Implantation ◽  
Significant Difference ◽  
Clinically Significant ◽  
Retrospective Comparative Study

Purpose: The aim of this study was to investigate the incidence of clinically significant anterior chamber inflammation in a combined surgery, namely, phacoemulsification and Ex-Press miniature glaucoma device implantation, compared to phacoemulsification alone. Methods: A retrospective comparative study of a consecutive series of 210 participants above 18 years of age diagnosed with significant cataract and who required glaucoma surgery, namely, Ex-Press miniature glaucoma device implantation or cataract alone in one or both eyes. All were operated on by a single experienced glaucoma surgeon in a single medical center. A total of 231 eyes were included in this study. All cases underwent an uneventful surgery and were examined the day following the surgery for visual acuity, intraocular pressure, and signs of excessive anterior chamber inflammation (Standardization of Uveitis Nomenclature grading ⩾ 3). Results: The combined group included 55 eyes of 51 patients, of whom 15 (27.3%) demonstrated excessive anterior chamber inflammation. The phacoemulsification group included 176 eyes of 159 patients, of whom 12 (6.7%) demonstrated excessive anterior chamber inflammation. Visual acuity and intraocular pressure measurements showed no statistically significant difference between the two groups. Conclusion: The Ex-Press glaucoma device is efficient, safe, and known for its inert nature. However, combination of this procedure with phacoemulsification surgery might result in a condition encouraging excessive inflammation, which eventually could lead to excessive anterior chamber inflammations if not treated vigorously. Emphasizing and recognizing the risks, especially in glaucoma patients, is important.

Treatment of chronic and extreme ocular hypotension following glaucoma surgery with intraocular platelet-rich plasma: A case report

2018 ◽  
Vol 29 (4) ◽  
pp. NP9-NP12 ◽  
Author(s):  
Omneya Abdalrahman ◽  
Alejandra E Rodriguez ◽  
Jorge L Alio Del Barrio ◽  
Jorge L Alio
Keyword(s):  
Intraocular Pressure ◽  
Anterior Chamber ◽  
Mitomycin C ◽  
Platelet Rich Plasma ◽  
Corneal Edema ◽  
Glaucoma Surgery ◽  
Applanation Tonometry ◽  
Safe Procedure ◽  
Rieger Syndrome ◽  
Ocular Hypotony

Purpose: To report a new approach for the treatment of severe ocular hypotony secondary to glaucoma filtering surgery with mitomycin C by injecting autologous eye platelet-rich plasma (E-PRP) in the anterior chamber to block excessive diffuse filtration through an abnormally thinned sclera. Methods: A 49-year-old patient with the Axenfeld–Rieger syndrome and severe chronic hypotony and corneal edema following filtering glaucoma surgery with mitomycin C received an isolated injection of 0.3 mL of autologous platelet-rich plasma in the anterior chamber. Results: Intraocular pressure measured by Goldman’s applanation tonometry 6 h after the procedure improved to 18 mmHg. Intraocular pressure remained stable along the full follow-up period of 6 month. No filtration or hypotony or any other complications were observed. Conclusion: Intracameral platelet-rich plasma (E-PRP) injection was an effective, rapidly effective, and safe procedure for treatment of severe chronic ocular hypotony following glaucoma filtrating surgery.

scholarly journals Inflammatory Molecules in Aqueous Humour and on Ocular Surface and Glaucoma Surgery Outcome

2010 ◽  
Vol 2010 ◽  
pp. 1-7 ◽  
Author(s):  
Barbara Cvenkel ◽  
Andreja Nataša Kopitar ◽  
Alojz Ihan
Keyword(s):  
Ocular Surface ◽  
Aqueous Humour ◽  
Human Leukocyte ◽  
Glaucoma Surgery ◽  
Antiglaucoma Medication ◽  
Surgery Outcome ◽  
Hla Dr ◽  
Antigen Presenting ◽  
Inflammatory Milieu ◽  
Inflammatory Molecules

Purpose. To investigate the influence of inflammatory molecules in the aqueous humour and on the ocular surface on the outcome of glaucoma surgery.Methods. Thirty patients who needed antiglaucomatous surgery were included. The interleukin- (IL-) 8, IL-1, IL-6, IL-10, tumour necrosis factor- (TNF-) ; and IL-12 were determined from aqueous humour preoperatively and the imprints of conjunctiva were analysed for expression of human leukocyte antigen- (HLA-)-DR after surgery by flow cytometry. The success of trabeculectomy was defined as intraocular pressure less than 21 mmHg without antiglaucoma medication.Results. Eyes with trabeculectomy failure at 3 months showed significantly higher TNF- and IL-6 levels in the aqueous than eyes with successful surgery. Increased expression of HLA-DR on epithelial cells and antigen-presenting cells was not associated with the trabeculectomy outcome.Conclusions. Higher preoperative levels of TNF- and IL-6 in aqueous humour may contribute to the development of inflammatory milieu and were associated with worse outcome of glaucoma surgery.

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