Numerical model to predict and compare the hypotensive efficacy and safety of minimally invasive glaucoma surgery devices

PLoS One. 2020 Sep 29;15(9):e0239324. doi: 10.1371/journal.pone.0239324. eCollection 2020.

Abstract

Purpose: To predict and compare the hypotensive efficacy of three minimally-invasive glaucoma surgery (MIGS) implants through a numerical model.

Methods: Post-implant hypotensive efficacy was evaluated by using a numerical model and a computational fluid dynamics simulation. Three different devices were compared: the XEN 45 stent (tube diameter, 45 μm), the XEN 63 stent (63 μm) and the PreserFlo microshunt (70 μm). The influence of the filtration bleb pressure (Bp) and tube diameter, length, and position within the anterior chamber (AC) on intraocular pressure (IOP) were evaluated.

Results: Using baseline IOPs of 25, 30 and 50 mmHg, respectively, the corresponding computed post-implant IOPs for each device were as follows: XEN 45: 17 mmHg (29% decrease), 19 mmHg (45%) and 20 mmHg (59%) respectively; XEN 63: 13 mmHg (48%), 13 mmHg (62%), and 13 mmHg (73%); PreserFlo: 12 mmHg (59%), 13 mmHg (73%) and 13 mmHg (73%). At a baseline IOP of 35 mmHg with an increase in the outflow resistance within the Bp from 5 to 17 mmHg, the hypotensive efficacy for each device was reduced as follows: XEN45: 54% to 37%; XEN 63: 74% to 46%; and PreserFlo: 75% to 47%. The length and the position of the tube in the AC had only a minimal (non-significant) effect on IOP (<0.1 mmHg).

Conclusions: This hydrodynamic/numerical model showed that implant diameter and bleb pressure are the two most pertinent determinants of hypotensive efficacy. In distinction, tube length and position in the AC do not significantly influence IOP.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Glaucoma / physiopathology*
  • Glaucoma / surgery*
  • Humans
  • Intraocular Pressure*
  • Minimally Invasive Surgical Procedures* / adverse effects
  • Models, Statistical*
  • Postoperative Period
  • Prostheses and Implants
  • Safety*
  • Treatment Outcome

Grants and funding

The publication of this work is funded by the normative grant of the community of Madrid,Spain. The work has been funded by a research grant from the San Carlos Clinical Hospital, Health Research Institute (IdISSC), Madrid, Spain. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript".