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oai:docta.ucm.es:20.500.14352/45582024-09-16T14:53:10Zcom_20.500.14352_14col_20.500.14352_15

00925njm 22002777a 4500 dc Ibarz Barberá, Marta author Hernández Verdejo, José Luis author Bragard, Jean author Burguete, Javier author Morales Fernández, Laura author Tañá Rivero, Pedro author Gómez De Liaño Sánchez, María Rosario author Teus Guezala, Miguel Ángel author 2021-11-18 Purpose: To measure the in vitro flow properties of the PRESERFLO implant for comparison with the theoretical resistance to flow. Methods: The PRESERFLO was designed to control the flow of aqueous humor according to the Hagen-Poiseuille (HP) equation. Scanning electron microscopy (SEM) was performed to analyze the ultrastructure, and flowmeasurementswere carried out using a gravity-flow setup. Results: SEM images of the PRESERFLO showed luminal diameters of 67.73 × 65.95 μm and 63.66 × 70.54 μm. The total diameter was 337.2 μm, and the wall was 154 μm wide. The theoretical calculation of the resistance to flow(R) for an aqueous humor (AH) viscosity of 0.7185 centipoises (cP) was 1.3 mm Hg/(μL/min). Hence, assuming a constant AH flow of 2 μL/min, the pressure differential across the device (�P) was estimated to be 2.6 mm Hg. The gravity-flow experiment allowed us to measure the experimental resistance to flow, which was RE =1.301mmHg/(μL/min), in agreement with the theoretical resistance to flow R given by the HP equation. Conclusions: The experimental and theoretical flow testing showed that the pressure drop across this device would not be large enough to avoid hypotony unless the resistance to outflowof the sub-Tenon space was sufficient to control the intraocular pressure in the early postoperative period. Translational Relevance: The fluid properties of glaucoma subconjunctival drainage devices determine their specific bleb-forming capacity and ability to avoid hypotony and therefore their safety and efficacy profile. Ibarz Barberá, M., Hernández Verdejo, J. L., Bragard, J. et al. «Evaluation of the Ultrastructural and In Vitro Flow Properties of the PRESERFLO MicroShunt». Translational Vision Science & Technology, vol. 10, n.o 13, noviembre de 2021, p. 26. DOI.org (Crossref), https://doi.org/10.1167/tvst.10.13.26. 2164-2591 10.1167/tvst.10.13.26 https://hdl.handle.net/20.500.14352/4558 https://doi.org/10.1167/tvst.10.13.26 http://www.tvstjournal.org/ Evaluation of the ultrastructural and in vitro flow properties of the PreserFlo® microShunt