Cerebrospinal Fluid PressureIntracranial PressureCerebrospinal FluidScleraOptic DiskCerebrospinal Fluid ShuntsIntraocular PressureIntracranial HypotensionExtracellular FluidPressureHeadacheOptic Nerve DiseasesOptic NerveGlaucomaDogsIsofluraneConnective TissueHydrostatic PressureBlood PressureCerebrospinal Fluid OtorrheaCerebrospinal Fluid ProteinsEthmoid BoneOphthalmoscopesTransducers, PressureEye EnucleationRetinal ArteryGlaucoma, Open-AngleExtracellular SpaceOcular HypertensionFinite Element AnalysisRetinal VeinElastinGlial Fibrillary Acidic Protein