Comparison of polypropylene and silicone Ahmed® glaucoma valves in the treatment of neovascular glaucoma: A 2-year follow-up

Lubiński, Wojciech; Krzystolik, Karol; Gosławski, Wojciech; Kuprjanowicz, Leszek; Mularczyk, Maciej

doi:10.17219/acem/66806

Cited by 6 publications

(4 citation statements)

References 12 publications

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“…This proved good biocompatibility of silicones was also confirmed in vitro by Windhövel et al who showed low proliferation indices and good cell-repellent properties for six different silicones [26]. Taken together, silicone GDDs demonstrated advantages for IOP control, success rates and fibrosis compared to other materials [3, 23, 25]. In the present study, granulocytes represented a small proportion of the observed inflammatory cells and are most likely part of a secondary reactive process rather than representing an infection at the implant site.…”

Section: Discussionmentioning

confidence: 55%

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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: Discussionmentioning

confidence: 55%

“…Silicones are often described as biocompatible, being chemically inert and stable [8, 24]. In glaucoma surgery, they show better results than other materials in the IOP control and also regarding the amount of inflammation, fibrin coating and encapsulation [23, 25]. Therefore, most of the GDDs are composed of silicones [3].…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2019

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“…The authors compared the clinical outcomes two years after the implantation of polypropylene or silicone Ahmed ® glaucoma valves in patients with neovascular glaucoma. Both materials have a long tradition in glaucoma treatment, but the authors drew attention to the influence of different materials on visual outcomes after Ahmed ® valve implantation for neovascular glaucoma, most likely due to the differences in the biocompatibility of the materials [24].…”

Section: Novel Biomaterials In the Surgical Treatment Of Glaucomamentioning

confidence: 99%

Novel Biomaterials in Glaucoma Treatment

Klézlová,

Bulíř,

Klápšťová

et al. 2024

Biomedicines

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Glaucoma is a significant cause of blindness worldwide, and its treatment remains challenging. The disease progressively leads to damage to the optic disc and thus loss of visual acuity and visual field. High intraocular pressure (IOP) is a common risk factor. There are three major methods to treat this disease: topical, laser, and surgical. None of these are completely satisfactory; therefore, alternatives using new biomaterials are being sought. Since biomaterial engineering has experienced significant growth in recent decades, its products are gradually being introduced to various branches of medicine, with the exception of ophthalmology. Biomaterials, such as glaucoma drainage implants, have been successfully used to treat glaucoma. There is significant ongoing research on biomaterials as drug delivery systems that could overcome the disadvantages of topical glaucoma treatment, such as poor intraocular penetration or frequent drug administration. This article summarizes the use of novel biomaterials for glaucoma treatment presented in the literature. The literature search was based on articles published in English on PubMed.gov, Cochranelibrary.com, and Scopus.com between 2018 and 2023 using the following term “biomaterials in glaucoma.” A total of 103 published articles, including twenty-two reviews, were included. Fifty-nine articles were excluded on the basis of their titles and abstracts.

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“…It has been shown that a rough surface of an implant leads to increased cell adhesion and, thus, to fibrous encapsulation [16]. Furthermore, polypropylenes and vivathanes seem to be associated with stronger inflammation than silicone [21,23]. Newer studies focus on the opportunity of coating the drainage devices with antiproliferative drugs to avoid postoperative fibrosis [24].…”

Section: Introductionmentioning

confidence: 99%

In Vitro Evaluation of Zinc Oxide Tetrapods as a New Material Component for Glaucoma Implants

Sonntag

Gniesmer

Gapeeva

et al. 2022

Life

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In our previous study we were able to show that zinc oxide (ZnO) tetrapods inhibit wound healing processes. Therefore, the aim of this study was to test the antiproliferative effect of two types of porous polydimethylsiloxane (PDMS)/ tetrapodal zinc oxide (ZnO-T) materials, as well as their usability for glaucoma implants. To find the best implant material, two different porous PDMS/ZnO-T materials were examined. One consisted of 3D interconnected PDMS coarse-pored foams with protruding ZnO-T particles; the other consisted of fine-pored 3D interconnected ZnO-T networks homogeneously coated by a thin PDMS film in the nanometer range. Fibroblast cell viability was investigated for both materials via MTT dye, and some implant material samples were further processed for electron microscopy. Both PDMS/ZnO-T materials showed reduced cell viability in the MTT staining. Furthermore, the electron microscopy revealed barely any fibroblasts growing on the implant materials. At the surface of the fine-pored implant material, however, fibroblasts could not be observed in the etched control samples without ZnO-T. It was found that post-processing of the material to the final stent diameter was highly challenging and that the fabrication method, therefore, had to be adapted. In conclusion, we were able to demonstrate the antiproliferative potential of the two different PDMS/ZnO-T materials. Furthermore, smaller pore size (in the range of tens of micrometers) in the implant material seems to be preferable.

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Comparison of polypropylene and silicone Ahmed® glaucoma valves in the treatment of neovascular glaucoma: A 2-year follow-up

Abstract: Background. Inflammation associated with biomaterials of Ahmed® glaucoma drainage devices may cause the formation of a capsule around the device and can thus have a significant influence on the level of intraocular pressure reduction.

Cited by 6 publications

References 12 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

Novel Biomaterials in Glaucoma Treatment

In Vitro Evaluation of Zinc Oxide Tetrapods as a New Material Component for Glaucoma Implants

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