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Outflow facility and extent of angle closure in a porcine model

Ying Hong1,2, Chao Wang1,3,4, Ralitsa Loewen1

  • 1Department of Ophthalmology, University of Pittsburgh Medical Center, Pittsburgh, PA, USA.

Graefe'S Archive for Clinical and Experimental Ophthalmology = Albrecht Von Graefes Archiv Fur Klinische Und Experimentelle Ophthalmologie
|April 5, 2019
PubMed
Abstract

Insights

A minimum of 90° of open anterior chamber angle circumference is sufficient to maintain normal aqueous humor outflow. This finding establishes a reproducible model for studying focal outflow regulation in the trabecular meshwork (TM).

Area of Science:

  • Ophthalmology
  • Ocular Physiology
  • Glaucoma Research

Background:

  • The regulation of aqueous humor outflow is crucial for maintaining intraocular pressure.
  • Understanding focal outflow regulation is key to developing targeted glaucoma therapies.
  • Previous models have limitations in investigating localized changes in outflow facility.

Purpose of the Study:

  • To determine the minimum anterior chamber angle circumference required for physiological outflow facility.
  • To develop a reproducible model for investigating focal outflow regulation in the trabecular meshwork (TM).

Main Methods:

  • Porcine eye anterior segments underwent cyanoacrylate-mediated angle occlusion at varying degrees (90°, 180°, 270°, 360°).
  • Outflow facility was measured at baseline and at multiple time points post-occlusion.
  • Canalograms assessed outflow patterns, and histomorphology of the TM was evaluated.

Main Results:

  • Complete (360°) angle occlusion significantly reduced outflow facility.
  • Partial occlusion (up to 270°) did not significantly alter outflow facility compared to baseline.
  • Histology confirmed no adverse effects on the unoccluded TM or aqueous plexus.

Conclusions:

  • A reproducible angle closure model was established using cyanoacrylate.
  • Ninety degrees of unoccluded anterior chamber angle circumference is adequate for maintaining physiological outflow.
  • This model can facilitate research into the regulation of outflow in healthy TM.
Keywords:
Angle closure modelGlaucomaOutflow facilityTrabecular meshwork

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