title: Regional choroidal blood flow and multifocal electroretinography in experimental glaucoma in rhesus macaques.
abstract: OBJECTIVE
  To test a hypothesis of regional variation in the effect of experimental glaucoma on choroidal blood flow (ChBF) and retinal function.
  
  
  METHODS
  Five rhesus macaques underwent laser trabecular destruction (LTD) to induce elevated intraocular pressure (IOP). Intraocular pressures were elevated for 56 to 57 weeks. Multifocal electroretinographic (mfERG) and multifocal visual evoked cortical potential (mfVEP) testing were performed at regular intervals before and during the period of IOP elevation. At euthanasia, the IOP was manometrically controlled at 35 (experimentally glaucomatous eye) and 15 (fellow control eye) mm Hg. Fluorescent microspheres were injected into the left ventricle. Regional ChBF was determined.
  
  
  RESULTS
  All of the experimentally glaucomatous eyes exhibited supranormal first-order kernel (K1) root mean square (RMS) early portions of the mfERG waveforms and decreased amplitudes of the late waveforms. The supranormality was somewhat greater in the central macula. Second-order kernel, first slice (K2.1) RMS mfVEP response was inversely correlated (R(2) = 0.97) with axonal loss. Total ChBF was reduced in the experimentally glaucomatous eyes. The mean blood flow was 893 ± 123 and 481 ± 37 μL/min in the control and glaucomatous eyes, respectively. The ChBF showed regional variability with the greatest proportional decrement most often found in the central macula.
  
  
  CONCLUSIONS
  This is the first demonstration of globally reduced ChBF in chronic experimental glaucoma in the nonhuman primate. Both the alteration of mfERG waveform components associated with outer retinal function and the reduction in ChBF were greatest in the macula, suggesting that there may be a spatial colocalization between ChBF and some outer retinal effects in glaucoma.
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States.
authors.forename: T Michael
authors.initials: TM
authors.lastname: Nork
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States.
authors.forename: Charlene B Y
authors.initials: CB
authors.lastname: Kim
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States.
authors.forename: Kaitlyn M
authors.initials: KM
authors.lastname: Munsey
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States.
authors.forename: Ryan J
authors.initials: RJ
authors.lastname: Dashek
authors.affiliation: Department of Ophthalmology and Visual Sciences, University of Wisconsin School of Medicine and Public Health, Madison, Wisconsin, United States.
authors.forename: James N Ver
authors.initials: JN
authors.lastname: Hoeve
mesh_terms: D000818:Animals; D001369:Axons / Q000473:pathology; D002829:Choroid / Q000098:blood supply*; D004195:Disease Models, Animal; D004596:Electroretinography / Q000379:methods; D005074:Evoked Potentials, Visual / Q000502:physiology; D005260:Female; D005902:Glaucoma, Open-Angle / Q000503:physiopathology*; D008253:Macaca mulatta / Q000502:physiology*; D009900:Optic Nerve / Q000473:pathology; D012039:Regional Blood Flow / Q000502:physiology*; D014793:Visual Cortex / Q000502:physiology
keywords: choroidal blood flow; experimental glaucoma; multifocal electroretinography