Differences in Outflow Facility between Angiographically Identified High- Versus Low-Flow Regions of the Conventional Outflow Pathways in Porcine Eyes

Clemens A. Strohmaier, Fiona S. McDonnell, Xiaowei Zhang, Daniel Wanderer, W. Daniel Stamer, Robert N. Weinreb, Alex S. Huang

Research output: Contribution to journalArticlepeer-review

8 Scopus citations

Abstract

PURPOSE. To investigate differences in outflow facility between angiographically determined high- and low-flow segments of the conventional outflow pathway in porcine eyes. METHODS. Porcine anterior segments (n = 14) were mounted in a perfusion chamber and perfused using Dulbecco's phosphate buffered solution with glucose. Fluorescein angiography was performed to determine high- and low-flow regions of the conventional outflow pathways. The trabecular meshwork (TM) was occluded using cyanoacrylate glue, except for residual 5-mm TM areas that were either high or low flow at baseline, designating these eyes as "residual high-flow"or "residual low-flow"eyes. Subsequently, outflow was quantitatively reassessed and compared between residual high-flow and residual low-flow eyes followed by indocyanine green angiography. RESULTS. Fluorescein aqueous angiography demonstrated high-flow and low-flow regions. Baseline outflow facilities were 0.320 ± 0.08 and 0.328 ± 0.10 μL/min/mmHg (P = 0.676) in residual high-flow and residual low-flow eyes before TM occlusion, respectively. After partial trabecular meshwork occlusion, outflow facility decreased to 0.209 ± 0.07 μL/min/mmHg (-32.66% ± 19.53%) and 0.114 ± 0.08 μL/min/mmHg (-66.57% ± 23.08%) in residual high- and low-flow eyes (P = 0.035), respectively. There was a significant difference in the resulting IOP increase (P = 0.034). CONCLUSIONS. Angiographically determined high- and low-flow regions in the conventional outflow pathways differ in their segmental outflow facility; thus, there is an uneven distribution of local outflow facility across different parts of the TM.

Original languageEnglish (US)
Article number29
JournalInvestigative Ophthalmology and Visual Science
Volume64
Issue number3
DOIs
StatePublished - Mar 2023
Externally publishedYes

Keywords

  • Aqueous angiography
  • aqueous humor outflow
  • trabecular meshwork

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience

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