Ocular anatomy

Eyeball

Orbit

Lacrimal apparatus

Extraocular musclesvisual organ & visual pathway

Vascular supply to the eyeball

SectionⅠ

Eyeball

Orbit

• Frontal• Zygomayic • Maxillary• Ethmoidal• Sphenoid • Lacrimal• Palatine

Lacrimal apparatus

1. Lacrimal gland2. 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

visual organ

Eyeball

appendages ： eyelid ， conjuncliva ， lacrimal ， ocular ， orbitalis apparatus muscles ，

Wall

content ： aqueous humor ， lens ， vitreous body

outer ： cornea ， sclera

media ： iris ， ciliary ， choroid

inner ： retina

visual retina pathway

Optic nerve

Optic chiasm

Optic tract

Lateral geniculate body

optic radiation

occipital lobeoptical center

visual pathway

Vascular supply to the eyeball

Artery• Central retinal artery,CRA• Ciliary artery,CA• Short posterior CA vein• Long posterior CA• Anterior ciliary CA 1. Central retinal

vein,CRV

2. Vortex vein

3. Anterior ciliary vein

Vascular supply to the eyeball

aqueous humorLens

Vitreous body

SectionⅡ

retina

Choroid

Ciliary body Iris

Cornea Sclera

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

Refractive power: 43D 2 ／ 3 of total

Cornea

Histologic structure ：

Cornea

Epithelium

Basement layer

Bowman’s membrane

Stroma

Descemet’s membrane

endothelium

1.Epithelium ：– 50μm

– 5 ～ 6 layers

• Squamous cell

• Aliform cell

• Basal cell

– Renewing cycle≈7 days

Cornea

2.Bowman’s membrane :

• 12 μm

• No cell

• Collagen ， matrix

• Scar

3.Stroma ：– 500 μm

– 2 ～ 3 ％ corneal cell

– 1 ％ matrix （ GAGs)

– Fibrous lamina

• 200 ～ 250 layers

• Parallel to surface

• Parallel collagen fiber

• Ordered arrangement

– Scar

Cornea

4.Descemet membrane ：– 10 ～ 12 μm

– No structure

– elasticcity

– Secreted by endothelial cell

– Basal membrane of endothelial cell

– regeneration

5.Endothelium ：– 5 μm

– Monolayer hexagen

• 500 000 cells

• Stop miosis

• Tight junction

• Pump

Cornea

• Blood vessel:

– Limbus vascular net

– Inner avascularity

– Less nutrition

Cornea

• Innervation :

– One of the most full tissue

– ophthalmic nerve of Trigeminal nerve(N5)

• Sensory nerve

• Parasympathetic nerve

– demyelination

– Available when edema

Physiology

• Enegy

• Transparency maintaining

– 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

Physiology

Transpar

ency

Transpar

ency

Transpar

ency

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

Histology

– Episclera ： vascular contain

– Sclera stroma ： collagen fiber

– Plate layer ： pigment cell

Sclera

Physiologic function：

• Appearance maintaining

• Content protection

• refraction

Sclera

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

• 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

iris

• 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↓

Ciliary body

• 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

aqueous humor

choroid

• ora serrata —— optic disc

• Full of pigment and BV

• Bruch membrane

• nutrition ， dark room

Histology

10 inner limiting membrane09 nerve fiber layer08 ganglion cell layer

07 inner plexiform layer

06 inner plexiform layer05 external plexiform layer

04 external;nuclear layer

03 outer limiting membrane02 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

• 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

Retina