Anatomic changes in Schlemm’s canal and collector channels in normal and primary open-angle glaucoma eyes using low and high perfusion pressures

Cheryl R. Hann, Andrew J. Vercnocke, Michael D. Bentley, Steven M. Jorgensen, Michael P Fautsch

Research output: Contribution to journalArticle

36 Citations (Scopus)

Abstract

PURPOSE. To examine the anatomy of Schlemm’s canal (SC) and collector channels (CCs) in normal human and primary open-angle glaucoma (POAG) eyes under low and high perfusion pressure.

METHODS. In normal (n = 3) and POAG (n = 3) eye pairs, one eye was perfused at 10 mm Hg while the fellow eye was perfused at 20 mm Hg for 2 hours. Eyes were perfusion fixed at like pressures, dissected into quadrants, embedded in Epon Araldite, and scanned by threedimensional micro-computed tomography (3D micro-CT). Schlemm’s canal volume, CC orifice area, diameter, and number were measured using ANALYZE software.

RESULTS. Normal eyes showed a larger SC volume (3.3-fold) and CC orifice area (9962.8 vs. 8825.2 μm2) and a similar CC diameter (34.3 ± 17.8 vs. 32.7 ± 13.0 μm) at 10 mm Hg compared to 20 mm Hg. In POAG eyes, SC volume (2.0-fold), CC orifice area (8049.2μm2- 6468.4 μm2), and CC diameter (36.2 ± 19.1 vs. 29.0 ± 13.8 μm) were increased in 10 mm Hg compared to 20 mm Hg perfusion pressures. Partial and total CC occlusions were present in normal and POAG eyes, with a 3.7-fold increase in total occlusions in POAG eyes compared to normal eyes at 20 mm Hg. Visualization of CCs increased by 24% in normal and by 21% in POAG eyes at 20 mm Hg compared to 10 mm Hg. Schlemm’s canal volume, CC area, and CC diameter were decreased in POAG eyes compared to normal eyes at like pressures.

CONCLUSIONS. Compensatory mechanisms for transient and short periods of increased pressure appear to be diminished in POAG eyes. Variable response to pressure change in SC and CCs may be a contributing factor to outflow facility change in POAG eyes.

Original languageEnglish (US)
Pages (from-to)5834-5841
Number of pages8
JournalInvestigative Ophthalmology and Visual Science
Volume55
Issue number9
DOIs
StatePublished - 2014

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Perfusion
Pressure
Primary Open Angle Glaucoma
Anatomy
Software
Tomography

Keywords

  • Anterior Segment
  • Collector Channel
  • Glaucoma
  • POAG
  • Schlemm’s Canal

ASJC Scopus subject areas

  • Ophthalmology
  • Sensory Systems
  • Cellular and Molecular Neuroscience
  • Medicine(all)

Cite this

Anatomic changes in Schlemm’s canal and collector channels in normal and primary open-angle glaucoma eyes using low and high perfusion pressures. / Hann, Cheryl R.; Vercnocke, Andrew J.; Bentley, Michael D.; Jorgensen, Steven M.; Fautsch, Michael P.

In: Investigative Ophthalmology and Visual Science, Vol. 55, No. 9, 2014, p. 5834-5841.

Research output: Contribution to journalArticle

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abstract = "PURPOSE. To examine the anatomy of Schlemm’s canal (SC) and collector channels (CCs) in normal human and primary open-angle glaucoma (POAG) eyes under low and high perfusion pressure.METHODS. In normal (n = 3) and POAG (n = 3) eye pairs, one eye was perfused at 10 mm Hg while the fellow eye was perfused at 20 mm Hg for 2 hours. Eyes were perfusion fixed at like pressures, dissected into quadrants, embedded in Epon Araldite, and scanned by threedimensional micro-computed tomography (3D micro-CT). Schlemm’s canal volume, CC orifice area, diameter, and number were measured using ANALYZE software.RESULTS. Normal eyes showed a larger SC volume (3.3-fold) and CC orifice area (9962.8 vs. 8825.2 μm2) and a similar CC diameter (34.3 ± 17.8 vs. 32.7 ± 13.0 μm) at 10 mm Hg compared to 20 mm Hg. In POAG eyes, SC volume (2.0-fold), CC orifice area (8049.2μm2- 6468.4 μm2), and CC diameter (36.2 ± 19.1 vs. 29.0 ± 13.8 μm) were increased in 10 mm Hg compared to 20 mm Hg perfusion pressures. Partial and total CC occlusions were present in normal and POAG eyes, with a 3.7-fold increase in total occlusions in POAG eyes compared to normal eyes at 20 mm Hg. Visualization of CCs increased by 24{\%} in normal and by 21{\%} in POAG eyes at 20 mm Hg compared to 10 mm Hg. Schlemm’s canal volume, CC area, and CC diameter were decreased in POAG eyes compared to normal eyes at like pressures.CONCLUSIONS. Compensatory mechanisms for transient and short periods of increased pressure appear to be diminished in POAG eyes. Variable response to pressure change in SC and CCs may be a contributing factor to outflow facility change in POAG eyes.",
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T1 - Anatomic changes in Schlemm’s canal and collector channels in normal and primary open-angle glaucoma eyes using low and high perfusion pressures

AU - Hann, Cheryl R.

AU - Vercnocke, Andrew J.

AU - Bentley, Michael D.

AU - Jorgensen, Steven M.

AU - Fautsch, Michael P

PY - 2014

Y1 - 2014

N2 - PURPOSE. To examine the anatomy of Schlemm’s canal (SC) and collector channels (CCs) in normal human and primary open-angle glaucoma (POAG) eyes under low and high perfusion pressure.METHODS. In normal (n = 3) and POAG (n = 3) eye pairs, one eye was perfused at 10 mm Hg while the fellow eye was perfused at 20 mm Hg for 2 hours. Eyes were perfusion fixed at like pressures, dissected into quadrants, embedded in Epon Araldite, and scanned by threedimensional micro-computed tomography (3D micro-CT). Schlemm’s canal volume, CC orifice area, diameter, and number were measured using ANALYZE software.RESULTS. Normal eyes showed a larger SC volume (3.3-fold) and CC orifice area (9962.8 vs. 8825.2 μm2) and a similar CC diameter (34.3 ± 17.8 vs. 32.7 ± 13.0 μm) at 10 mm Hg compared to 20 mm Hg. In POAG eyes, SC volume (2.0-fold), CC orifice area (8049.2μm2- 6468.4 μm2), and CC diameter (36.2 ± 19.1 vs. 29.0 ± 13.8 μm) were increased in 10 mm Hg compared to 20 mm Hg perfusion pressures. Partial and total CC occlusions were present in normal and POAG eyes, with a 3.7-fold increase in total occlusions in POAG eyes compared to normal eyes at 20 mm Hg. Visualization of CCs increased by 24% in normal and by 21% in POAG eyes at 20 mm Hg compared to 10 mm Hg. Schlemm’s canal volume, CC area, and CC diameter were decreased in POAG eyes compared to normal eyes at like pressures.CONCLUSIONS. Compensatory mechanisms for transient and short periods of increased pressure appear to be diminished in POAG eyes. Variable response to pressure change in SC and CCs may be a contributing factor to outflow facility change in POAG eyes.

AB - PURPOSE. To examine the anatomy of Schlemm’s canal (SC) and collector channels (CCs) in normal human and primary open-angle glaucoma (POAG) eyes under low and high perfusion pressure.METHODS. In normal (n = 3) and POAG (n = 3) eye pairs, one eye was perfused at 10 mm Hg while the fellow eye was perfused at 20 mm Hg for 2 hours. Eyes were perfusion fixed at like pressures, dissected into quadrants, embedded in Epon Araldite, and scanned by threedimensional micro-computed tomography (3D micro-CT). Schlemm’s canal volume, CC orifice area, diameter, and number were measured using ANALYZE software.RESULTS. Normal eyes showed a larger SC volume (3.3-fold) and CC orifice area (9962.8 vs. 8825.2 μm2) and a similar CC diameter (34.3 ± 17.8 vs. 32.7 ± 13.0 μm) at 10 mm Hg compared to 20 mm Hg. In POAG eyes, SC volume (2.0-fold), CC orifice area (8049.2μm2- 6468.4 μm2), and CC diameter (36.2 ± 19.1 vs. 29.0 ± 13.8 μm) were increased in 10 mm Hg compared to 20 mm Hg perfusion pressures. Partial and total CC occlusions were present in normal and POAG eyes, with a 3.7-fold increase in total occlusions in POAG eyes compared to normal eyes at 20 mm Hg. Visualization of CCs increased by 24% in normal and by 21% in POAG eyes at 20 mm Hg compared to 10 mm Hg. Schlemm’s canal volume, CC area, and CC diameter were decreased in POAG eyes compared to normal eyes at like pressures.CONCLUSIONS. Compensatory mechanisms for transient and short periods of increased pressure appear to be diminished in POAG eyes. Variable response to pressure change in SC and CCs may be a contributing factor to outflow facility change in POAG eyes.

KW - Anterior Segment

KW - Collector Channel

KW - Glaucoma

KW - POAG

KW - Schlemm’s Canal

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U2 - 10.1167/iovs.14-14128

DO - 10.1167/iovs.14-14128

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JO - Investigative Ophthalmology and Visual Science

JF - Investigative Ophthalmology and Visual Science

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