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Ocular anatomy SectionⅠ Eyeball Orbit Lacrimal apparatus Extraocular muscles visual organ & visual pathway Vascular supply to the eyeball Eyeball Orbit • • • • • • • Frontal Zygomayic Maxillary Ethmoidal Sphenoid Lacrimal Palatine Lacrimal apparatus 1. Lacrimal gland 2. Lacrimal passages • • • • Lacrimal puncta Lacrimal canaliculi Lacrimal sac Nasolacrimal duct Extraocular muscles • • • • • • Medial rectus Inferior Lateral rectus Superior rectus Superior oblique Inferior oblique Extraocular muscles visual organ outer:cornea,sclera Wall Eyeball media:iris,ciliary,choroid inner:retina content:aqueous humor,lens,vitreous body visual organ visual retina Optic Optic Optic pathway nerve chiasm tract Lateral optic occipital lobe geniculate body radiation optical center appendages:eyelid,conjuncliva,lacrimal, ocular,orbitalis apparatus muscles, visual pathway Vascular supply to the eyeball Artery • Central retinal artery,CRA • Ciliary artery,CA • • • Short posterior CA Long posterior CA Anterior ciliary CA vein 1. Central retinal vein,CRV 2. Vortex vein 3. Anterior ciliary vein Vascular supply to the eyeball SectionⅡ Cornea Sclera Iris aqueous humor Lens Choroid Vitreous body retina Ciliary body Cornea • Oval – transverse:11.5~12mm – vertical:10.5~11mm • curvature:anterior:7.8mm posterior:6.8mm • antisymmetry • thickness:centre:0.5~0.55mm periphery:1mm • Refractive index:1.3771 Cornea Refractive power: 43D 2/3 of total Cornea Histologic structure: Epithelium Basement layer Bowman’s membrane Stroma Descemet’s membrane endothelium Cornea 1.Epithelium : 2.Bowman’s membrane : – 50μm • 12 μm – 5~6 layers • Squamous cell • No cell • Aliform cell • Collagen ,matrix • Basal cell – Renewing cycle≈7 days • Scar Cornea 3.Stroma : 4.Descemet membrane: – 500 μm – 10~12 μm – 2~3% corneal cell – No structure – 1%matrix(GAGs) – Fibrous lamina • 200~250 layers • Parallel to surface • Parallel collagen fiber • Ordered arrangement – Scar – elasticcity – Secreted by endothelial cell – Basal membrane of endothelial cell – regeneration Cornea 5.Endothelium : – 5 μm – Monolayer hexagen • 500 000 cells • Stop miosis • Tight junction • Pump Cornea • Blood vessel: – Limbus vascular net • Innervation : – One of the most full tissue – ophthalmic nerve of Trigeminal nerve(N5) – Inner avascularity • Sensory nerve – Less nutrition • Parasympathetic nerve – demyelination – Available when edema Physiology • Enegy • Transparency maintaining Physiology – Anatomy • avascularity,no pigment • Epithelium ordered arrangement ,no keratinization • Stroma ordered arrangement • Endothelium ordered arrangement – Tight junction of endothelium – Related hydration • pump • Hydration of stroma Sclera • Posterior 5/6 of fibrous mem • White , firm • Forward connect cornea-corneoscleral limbus • Backward :optic nerve – – Sheath Cribriform plate • Thickness Muscle attachment:0.3mm Nerve surrounding:1.0mm Sclera Histology – Episclera :vascular contain – Sclera stroma:collagen fiber – Plate layer:pigment cell Sclera Physiologic function: • Appearance maintaining • Content protection • refraction Corneoscleral limbus • Transition zone: – ant:bowman`s terminal-descemet terminal – pos:scleral spur/iris root vertical plane • 1.5~2.0mm width • appearance – Semitransparant zone – White sclera • Angle of AC Angle of anterior chamber • Ant-lateral:corneoscleral limbus • Pos-medial:anterior ciliary and iris root • Include: – Schwalbe line – trabecular reticulum – Schlenm cannel – Scleral spur – Ciliary zone – Iris root iris • Disc • Chamber separation • Puple :2.5~4.0mm • whorl – Puple area – Ciliary zone iris Histology • Anterior surface layer • Stroma layer • chromocyte • sphincter muscle of pupil——parasympathetic nerve • dilator muscle of pupil——sympathetic nerve • Pigmentary epithelium iris pupil – Regulation of incident light volumn – Depth of focus and aberration Ciliary body • Connect iris root and choroid • Triangle – corona:2mm • Ciliary process:40~80个 – Pars plana:4mm • Muscle ——parasympathetic nerve – – – meridional fibers Radial fibers Circular fibers Ciliary body contraction: – Accomodation • Ring muscle contraction • Suspensory ligament internal traction,loose – IOP • meridional fibers contraction • Choroid shift forward,scleral spur draw backward – Open AAC/scleral vein – Choroid blood volumn↑ – Ciliary blood volumn↓ aqueous humor • Full filled • 0.2ml • Refractive index:1.3774 • Drainage path – ciliary posterior chamber pupil anterior chamber trabecular Schlemm canal collection canal aqueous vein ciliary veins – choroid aqueous humor • physiology – dioptric media – IOP maintain – Uniform RI of conea – metabolism – accomodation choroid • ora serrata —— optic disc • Full of pigment and BV • Bruch membrane • nutrition,dark room Histology 10 inner limiting membrane 09 nerve fiber layer 08 ganglion cell layer 07 inner plexiform layer 06 inner plexiform layer 05 external plexiform layer 04 external;nuclear layer 03 outer limiting membrane 02 retinal rod and cone cell layer 01 RPE Lens • Transparent ,double convex mirror • Between pupil-iris and vitreous body • Diopter :19D – ant:10mm – pos:6mm • Axis length:4mm • D:9mm • RI:1.4371 Lens • Nonuniform RI • Elasticcity body • Accomodation intracapsular——RI Vitreous body • • • • Transparent colloid 4.5ml RI:1.3360≈aqueous humor Tight junction site: – – – – • Disc egde Fovea surrounding Basement of vitreous body Posterior capsular(youth) Cloquet canal – – Lens posterior pole——in front of disc Primary vitreous Retina • • • Transparent ,thin Anterior rim:ora serrata macula/fovea – – – • Posterior pole Keen RPE-pigment optic disk – – – – Disc form Nasal side of macula: 3mm 1.5×1.75mm optic cup C/D < 0.3 Retina Special side: – Optic disc • Only optic nerve fiber • Physiological blind spot – macular • thinnest • Only rod —— photopic vision,colour vision • Other layers abscent • Neuron singlet link • keen