TY - JOUR
T1 - A novel bilayered expanded polytetrafluoroethylene glaucoma implant creates a permeable thin capsule independent of aqueous humor exposure
AU - Bicket, Amanda Kiely
AU - Szeto, Julia
AU - Roeber, Peter
AU - Towler, Jeff
AU - Troutman, Mitch
AU - Craven, E. Randy
AU - Khatana, Anup
AU - Ahmed, Ike
AU - Quigley, Harry
AU - Ramulu, Pradeep
AU - Pitha, Ian F.
N1 - Funding Information:
This work was sponsored by a grant from W.L. Gore & Associates, Inc., Newark, Delaware. P. R., J. T., and M. T. are employees of the research sponsor, W.L. Gore & Associates, Inc. and received no additional compensation, funding, or support in connection with the study. All other authors are paid consultants to W.L. Gore & Associates, Inc.
Publisher Copyright:
© 2020 The Authors. Bioengineering & Translational Medicine published by Wiley Periodicals LLC on behalf of American Institute of Chemical Engineers.
PY - 2021/1
Y1 - 2021/1
N2 - The purpose of these studies was to evaluate clinical, functional, and histopathological features of glaucoma drainage implants (GDIs) fabricated from novel, custom-tailored expanded polytetrafluoroethylene (ePTFE). Implants of matching footprints were fabricated from silicone (Control) and novel, bilayered ePTFE. ePTFE implants included: (a) one that inflated with aqueous humor (AH) (High), (b) one that inflated with a lower profile (Low), (c) an uninflated implant not connected to the anterior chamber (Flat), and (d) one filled with material that did not allow AH flow (Filled). All implants were placed in adult New Zealand White rabbits and followed over 1–3 months with clinical exams and intraocular pressure. The permeability of tissue capsules surrounding GDIs was assessed using constant-flow perfusion with fluoresceinated saline at physiologic flow rates. After sacrifice, quantitative histopathological measures of capsule thickness were compared among devices, along with qualitative assessment of cellular infiltration and inflammation. Capsular thickness was significantly reduced in blebs over ePTFE (61.4 ± 53 μm) versus silicone implants (193.6 ± 53 μm, p =.0086). AH exposure did not significantly alter capsular thickness, as there was no significant difference between High and Filled (50.9 ± 29, p =.34) implants. Capsules around ePTFE implants demonstrated permeability with steady-state pressure: flow relationships at physiologic flow rates and rapid pressure decay with flow cessation, while pressure in control blebs increased even at low flow rates and showed little decay. Perfused fluorescein dye appeared beyond the plate border only in ePTFE implants. ePTFE implants are associated with thinner, more permeable capsules compared to silicone implants simulating presently used devices.
AB - The purpose of these studies was to evaluate clinical, functional, and histopathological features of glaucoma drainage implants (GDIs) fabricated from novel, custom-tailored expanded polytetrafluoroethylene (ePTFE). Implants of matching footprints were fabricated from silicone (Control) and novel, bilayered ePTFE. ePTFE implants included: (a) one that inflated with aqueous humor (AH) (High), (b) one that inflated with a lower profile (Low), (c) an uninflated implant not connected to the anterior chamber (Flat), and (d) one filled with material that did not allow AH flow (Filled). All implants were placed in adult New Zealand White rabbits and followed over 1–3 months with clinical exams and intraocular pressure. The permeability of tissue capsules surrounding GDIs was assessed using constant-flow perfusion with fluoresceinated saline at physiologic flow rates. After sacrifice, quantitative histopathological measures of capsule thickness were compared among devices, along with qualitative assessment of cellular infiltration and inflammation. Capsular thickness was significantly reduced in blebs over ePTFE (61.4 ± 53 μm) versus silicone implants (193.6 ± 53 μm, p =.0086). AH exposure did not significantly alter capsular thickness, as there was no significant difference between High and Filled (50.9 ± 29, p =.34) implants. Capsules around ePTFE implants demonstrated permeability with steady-state pressure: flow relationships at physiologic flow rates and rapid pressure decay with flow cessation, while pressure in control blebs increased even at low flow rates and showed little decay. Perfused fluorescein dye appeared beyond the plate border only in ePTFE implants. ePTFE implants are associated with thinner, more permeable capsules compared to silicone implants simulating presently used devices.
KW - bleb
KW - capsule
KW - expanded polytetrafluoroethylene (ePTFE)
KW - fibrosis
KW - glaucoma
KW - glaucoma drainage implant (GDI)
KW - intraocular pressure (IOP)
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U2 - 10.1002/btm2.10179
DO - 10.1002/btm2.10179
M3 - Article
C2 - 33532583
AN - SCOPUS:85089558013
SN - 2380-6761
VL - 6
JO - Bioengineering and Translational Medicine
JF - Bioengineering and Translational Medicine
IS - 1
M1 - e10179
ER -