Visual system Oculus et structurae pertinentes © David Kachlík 30.9.2015.

Visual systemVisual system

Oculus et structurae Oculus et structurae pertinentespertinentes

© David Kachlík 30.9.2015

Odilo Redon© David Kachlík 30.9.2015

Orbita = Orbita = OrbitOrbit

• tetrahedral pyramid tilted dorsally

• aditus x apex

• 10 openings + their contetnt

• m. orbitalis Mülleri – smooth muscle in the fissura orbitalis inferior

• content: eyeball, oculomotor muscles, fat pad and related structures


Orbita – osseous wallsOrbita – osseous walls

• cranially: pars orbitalis o. frontalis (fovea trochlearis + spina trochlearis, incisura/foramen frontalis/supraorbitalis, fossa glandulae lacrimalis), ala minor o. sphenoidalis (fissura orbitalis sup.)

• medially: processus frontalis maxillae (fossa sacci lacrimalis), os lacrimale, lamina orbitalis o. ethmoidalis (foramen ethmoidale ant. et post.), ala minor o. sphenoidalis

• laterally: facies orbitalis o. zygomatici (foramen zygomaticoorbitale), facies orbitalis alae majoris o. sphenoidalis


Orbita – osseous wallsOrbita – osseous walls

• caudally: facies orbitalis o. zygomatici, facies orbitalis corporis maxillae (sulcus et canalis infraorbitalis, fissura orbitalis inf.), processus orbitalis o. palatini

• aditus orbitae → apex orbitae

• orbita is divided by theoretical planes into 3 levels


Orbita – related structuresOrbita – related structures

• medially: cellulae ethmoidales (via very thin lamina orbitalis ossis ethmoidalis)

• caudally: sinus maxillaris

• cranially: fossa cerebri anterior

• dorsally: sinus cavernosus + fossa pterygopalatina


Visual systemVisual system

• bulbus oculi = eyeball

• structurae pertinentes oculi = related structures of the eye

• topography: regio orbitalis

• development


EyeballEyeball

• tunica fibrosa (externa)

• tunica vasculosa (media)

• tunica interna (nervosa)

• corpus vitreum (vitreous body) + lens


EyeballEyeball

• polus anterior, posterior

• equator x meriadiani• axis bulbi externus,

internus• axis opticus (= „linea

visus“)


Tunica fibrosa (externa)Tunica fibrosa (externa)

• sclera

• cornea


Tunica fibrosa (externa)Sclera

• dense connective tissue (= reticulum trabeculare), collagen fibres, fibroblasts, ground substance

• lamina episcleralis, substantia propria, lamina fusca

• lamina cribrosa (entrance of n. II.)• 5/6th of the eyeball surface, ø 2,2 cm• sinus venosus sclerae (canalis Schlemmi s. Lauthi)• sulcus sclerae – sclerocorneal junction = limbus

corneae (angulus sclerocornealis)© David Kachlík 30.9.2015

Tunica fibrosa (externa)Cornea

• perfectly transparent, non-vascular• limbus, vertex• 5 layers

– epithelium anterius cornae (stratified squamous ep.)– lamina limitans anterior (Bowman´s membrane)– substantia propria corneae– lamina limitans posterior (Descement´s membrane)– epithelium posterius corneae („endothelium“)

• 11 x 12 mm - physiological astigmatism


Tunica vasculosa (media) = Uvea

• choroidea

• corpus ciliare (ciliary body)

• iris


Tunica vasculosa (media) = Choroidea

• lamina suprachoroidea (= lamina fusca sclerae)• spatium perichoroideum• lamina vasculosa (choroideal stroma)

– larger vessels, connective tissue, smooth muscle cells, nerves

• lamina choriocapillaris– capillaries

• lamina basalis = Bruch´s membrane– BM of pigment epithelium and capillaries + connective tissue


Tunica vasculosa (media) = Corpus ciliare

• annular shape, triangular profile

• processus + plicae ciliares

• orbiculus (external part), corona (internal part)

• smooth musculus ciliaris– fibrae meridionales,

radiales, circulares, longitudinales © David Kachlík 30.9.2015

Tunica vasculosa (media)= Corpus ciliare

• stroma– m. ciliaris: parasympathetic accomodation

focus at near (focus at far is assured with the elastic choroidea)– capillaries and nerves supplying the muscle

• epithelial cover – production of humor aquosus– BL – continuation of Bruch´s membrane– pigment epithelium – (continuation of pigm. epith. of

retina)– cilliary canal– nonpigment epithelium (continuation of sensory

epith. of retina)– BL– fibrae zonulares – fixation of lens© David Kachlík 30.9.2015

Tunica vasculosa (media)= Iris

• annular and flat shape• function of photograph stop (shutter)• margo ciliaris (external), m. pupillaris (internal)• pupilla• anulus iridis major + minor (containing circulus

arteriosus iridis major + minor)• m. sphincter pupillae (parasymp.) – miosis

(circular) • m. dilatator pupillae (symp.) – mydriasis (radiate)


Tunica vasculosa (media) = Iris

• plicae iridis, stroma iridis• anterior surface

– no epithelium cover– fibroblasts and melanocytes (colour)– dentate line – remnant of membrana pupillaris

Wachendorfi

• posterior surface– 2 layers of pigment epithelium– internal pigment– external myoepithelial

• m. sphincter pupillae• m. dilatator pupillae


Lens

• polus anterior, posterior• axis, equator, radii (seams in shape of Y and

inverted-Y)• capsula lentis• substantia lentis – cortex, nucleus• zonula ciliaris Zinni

– fibrae zonulares– spatia zonularia

catharact - replacement© David Kachlík 30.9.2015

Lens

• transparen biconvex nonvascular structure• capsula lentis – similar to BL• epithelium lentis – unilayered cubic

– anterior surface only

• substantia lentis– cortical – contains oblong cells (fibres) with organels

and nucleus– nuclear – cellular fibres without organels and nucleus– cells contain specific proteins (filensin, crystallins)


Accomodation

• focus at near– contraction of m. ciliaris– fibrae zonulares relax– lens bulges– parallel contraction of m. sphincter pupillae (=

miosis)

• focus at far– vessels tonus keeps fibrae zonulares tightened– lens is flatened– contraction of m. dilatator pupillae (= mydriasis)


Corpus vitreum = Vitreous body

• membrana, stroma, humor vitreus• 99% of water• hyaluronic acid, collagen fibres• cells – hyalocytes – during development only!• no regeneration ! – in trauma flows out and

replaced with aqueous humor• canalis hyaloideus Cloqueti – remnant of fetal

arteria hylaloidea• fossa hyaloidea• maintains the internal eyeball pressure,

compress retina to the choroidea© David Kachlík 30.9.2015

Humor aquosus= Aqeous humor

• produced by corpus ciliare• absorbed in angulus iridocornealis• 0,2-0,3 ml of pellucid and colourless fluid• daily production - 3 ml• content: 0,7-1,2% NaCl, glucose and urea traces

(0,1%), no proteins!• corresponds to the lymph inside the eyeball• intraocular pressure: 14-17 mmHg

intraocular pressure compression of retina glaucoma © David Kachlík 30.9.2015

Camerae bulbi = Chambers of eyeball

• camera postrema s. vitrea– between corpus ciliare, lens and retina– contains corpus vitreum– spatium retrozonulare

• camera posterior– between iris, lens and corpus ciliare– contains and produces humor aquosus

• camera anterior– between cornea and iris– angulus iridocornealis– contains and absorbs humor aquosus


Angulus iridocornealis = Iridocorneal angle

• in site of sclerocorneal junction

• trabecular net in the posterior wall = spatia anguli i.c. = Fontana´s spaces

• no direct connection to Schlemm´s canal

• reabsorption of humor aquosus

• maintains the intraocular pressure

• !!! no application of parasympatheticolytics in patient with glaucoma !!!


OCT

Optic coherent

tomography

measurements of light reflexion © David Kachlík 30.9.2015

Break


Tunica interna (nervosa)= Retina

• pars caeca – pars iridica– pars ciliaris

• ora serrata

• pars optica – 11 layers– pigment part– sensory part


Tunica interna (nervosa)Retina – pigment part

• unilayered cubic epithelium• cells with thight junctions• apical cell parts contain melanin granules• encompass the external segments of sensory

cells• interfotoreceptor matrix

nutrition of cells, regeneratin of fotopigment, degradation of membranous discs© David Kachlík 30.9.2015

Tunica interna (nervosa) Retina – sensory part

• light-sensitive neurons (transducers)– rods and cones

• trasmission neurons (integraters)– bipolar and ganglionic cells

• association neurons– horizontal and amacrinne cells

• suppoting cells (glia)– Müller´s cells


Tunica sensoria (interna)Rods = Bacilli

• synaptic disc• axon• nucleus• internal segment

– GA, ER, MIT; synthesis of ATP and rhodopsin

• external segment– membranous discs with fotopigment– migrate externally until the separate

black and white vision© David Kachlík 30.9.2015

Tunica sensoria (interna)Rods = Coni

• synaptic foot• fotopigment - iodopsin• external segment

– membranous discs with fotopigment• communicate with environment

• colour vision– 3 types of cones– „blue“ – 420 nm– „green“ – 535 nm– „red“ – 565 nm© David Kachlík 30.9.2015

Tunica sensoria (interna)Transmisison neurons (Integraters)

• Bipolar cells– rod-like bipolar cells– cone-like bipolar cells – dwarf x diffused– contacts with ganglionic cells

• Ganglionic cells– diffused type – contact with more bipolare cells– dwarf type – contact with dwarf bipolare cell– axons of ganglionic cells form nervus opticus


Tunica sensoria (interna)Association neurons

only neuritic processes – in both directions

• horizontal cells– contacts with rods and cones

• amacrinne cells– contacts with bipolar and ganglionic cells

modification and synchronization of signal


Tunica sensoria (interna)Supporting cells

• Müller´s cells– macroglia– their BL = membrana limitans interna– zonulae adherentes with rods and cones

• = membrana limitans externa


Tunica sensoria (interna)Layers of optic part of retina

• 11 layers

!!! do not be frightened !!!


Tunica sensoria (interna) Layers of optic part of retina

• stratum pigmentosum (1.)• stratum nervosum (2.-10.)

– stratum segmentorum externorum et internorum(2.)

– stratum limitans externum (3.)– stratum nucleare externum (4.)– stratum plexiforme externum (5.)– stratum nucleare internum (6.)– stratum plexiforme internum (7.)– stratum ganglionicum (8.)– stratum neurofibrarum (9.)– stratum limitans internum (10.)© David Kachlík 30.9.2015

Tunica interna (nervosa) Specific spots of retina

discus n. optici (= blind spot)

• n. II leaves the eyeball

• no light-sensitive cells excavatio disci


Tunica sensoria (interna)Specific spots of retina

• fovea centralis („macula lutea; yellow spot“)–distant layers diverted laterally–sharpest and most brilliant colour

vision spot–cones only (100.000 cones)

foveola (2500 cones)


OCT

Optic coherent

tomography


OCT


OCT

ABRUPTIO RETINAE


Arterial supply of the eye

a. carotis interna a. ophtalmica • aa. ciliares posteriores breves choroidea• aa. ciliares longae (24) corpus ciliare +

iris• aa. musculares aa. ciliares ant., a.

epiclerales, aa. conjuctivales lat.• a. centralis retinae retina• a. lacrimalis aa. palpebrales lat.• aa. palpebrales med. aa. conjuctivales med.© David Kachlík 30.9.2015

Vasa sanguinea retinae– fundus oculi

a. centralis retinae arteriolae

• a. temporalis sup.+inf.• a. nasalis sup.+inf.• a. macularis sup.+inf.

(+ media)

veins correspond to arteries, they often cross


A. cilioretinalis (cilioretinal a.)

• present in 10-33% of eyes• branches from the a. ciliaris posterior brevis• exits the discus n.II separately from a. centralis

retinae• additional supply to macula lutea from

choroidal circulation• provide a small amount of blood supply to the

retina when a. centralis retinae is occluded• 90% located temporally, 10% nasally• occlusion of a. cilioretinalis → central visual

loss• occlusion of a. centralis retinae → spare

central vision and macula lutea© David Kachlík 30.9.2015

A. cilioretinalis (cilioretinal a.)


Venous drainage of eye – 3 directions

• vv. episclerales

• vv. ciliares ant. vv. sclerales sinus venosus sclerae Schlemmi s. Lauthi

• vv. vorticosae (4 in quadrants of eyeball)

• v. centralis retinaev. ophthalmica sup. sinus cavernosusv. ophthalmica inf. plexus pterygoideusv. angularis v. facialis v. jugularis int.

! danger of inflammation spreading !© David Kachlík 30.9.2015

Nervous supply of eye

• n. opticus – special sensory– pars intraocularis, canalis, itracranialis– vagina interna, externa

• n. ophthalmicus nn. ciliares longi – somatosensory

• n. lacrimalis, n. frontalis, n. nasociliaris – for surrounding structures

• nn. ciliares breves ganglion ciliare – autonomic (visceromotor)

(sympathetic fibres non-interpolated, parasympathetic interpolated)

• n.III., n. IV., n.VI – somatomotor


Nervus opticus

• evagination of diencephalon (thalamus opticus)

• axons separated with endoneurium

• covered with meninges

• a. et v. centralis retinea runs inside the nerve


VISUAL PATHWAYProjection → Ascendent → Sensoric

4 - neuronal, partially crossed

1. neuron: rod and cones of retine2. neuron: bipolar cells 3. neuron: ganglional cells n. II chiasma

opticum corpus geniculatum laterale4. neuron: cells in corpus geniculatum laterale

tractus geniculocorticalis (= radiatio optica Gratioleti) lobus occipitalis, area 17 (around sulcus calcarinus)• Meyer´s loop into temporal lobe© David Kachlík 30.9.2015

VSIUAL PATHWAY branches from 3rd neuron

• to hypothalamus (nucleus suprachiasmaticus) – converts optical signals to highest vegetativ centres (seeing meal = salivation)

• pathways of pupillar reflex - through area pretectalis

• to nucleus accessorius dorsalis n. III /Edinger-Westphal/ - parasymphatetic pathway with n. III ganglion ciliare nn. ciliares breves m. ciliaris et m. sphincter pupillae /miosis + accomodation/

• to reticular formation tractus reticulospinalis centrum ciliospinale /Budge/ C8-Th1 sympathetic pathway in truncus symphaticus ganglion cervicale superius plexus caroticus internus et ophtalmicus nn. ciliares breves m. dilatator pupillae /mydriasis/

• pathway for convergence nucleus interstitialis /Cajal/ fasciculus longitudinalis medialis nuclei of all ophtalmogyric nerves

• tectal optic circuit - tractus tectospinalis (control of synkinesis of eyes, head, neck to visual stimuli and for coordination with gross movements of body)


Structurae oculi accessoriae= Related strctures of eye

• Apparatus ligamentosus

• Palpebrae = Eyelids

• Conjunctiva

• Apparatus lacrimalis

• Apparatus muscularis

• Supercilium


Apparatus ligamentosus

• periorbit

• vagina bulbi (= capsula Tenoni)– lig. suspensorium bulbi

• spatium episclerale

• corpus adiposum orbitae

• fasciae musculares


Tunica conjunctiva

• t.c. bulbi x t.c. palpebrarum• fornix superior, inferior• continuation of epithelium of cornea, dorsally to

the eyelid, covers anterior surface of the eyeball• stratified cylindric epithelium• contains goblet cells• glanduale conjuctivales Wolfringi• caruncula lacrimalis


Víčka = Palpebrae

• palpebra superior, inferior• tarsus superior (10 mm), inferior (5 mm)• lig. palpebrale med. (2 pruhy) + lat.• facies ant.+post., rima palpebrarum, commissura

palp. med.+lat., limbus ant.+ post.• angulus oculi med.+ lat.• m. tarsalis sup. (Mülleri) + inf. – smooth muscles• pars palpebralis m. orbicularis oculi - n. VII• m. levator palpebrae superioris - n. III• cilia © David Kachlík 30.9.2015

Palpebrae = Eyelids

• palpebra superior, inferior• tarsus superior (10 mm), inferior (5 mm)• lig. palpebrale med. (2 bands) + lat.• facies ant.+post., rima palpebrarum, commissura

palp. med.+lat., limbus ant.+ post.• angulus oculi med.+ lat.• m. tarsalis sup. (Mülleri) + inf. – smooth muscles• pars palpebralis m. orbicularis oculi - n. VII• m. levator palpebrae superioris - n. III• cilia © David Kachlík 30.9.2015

Palpebrae = Eyelids• external cutaneous part

– keratinizing stratified squamous epithelium

– gl. sebaceae Zeissi • inflammation - hordeolum

– cilia + gl. ciliares Molli• apocrinne glands

• m. orbicularis oculi• tarsus

– fibroelastic plate– gl. tarsales Meibomi

• sebaceous glands - chalazion

• internal conjunctival part– sulcus et epithelial transition


Apparatus lacrimalis = Lacrimal apparatus

• glandula lacrimalis – pars orbitalis + palpebralis– 12-15 separate ductuli excretorii

• glandulae lacrimales accessoriae Krausei• rivus lacrimalis• lacus, papilla, caruncula lacrimalis• puctum, canaliculus lacrimalis• saccus lacrimalis ductus nasolacrimalis

(plica lacrimalis Hasneri) meatus nasi inf.© David Kachlík 30.9.2015

Glandula lacrimalis• tubuloacinar serous glands with

myoepithelial cells


Muscular apparatus

• mm. recti bulbi: sup., inf., med., lat. (VI.)• mm. obliqui bulbi: inf., sup.(IV.)

– /fovea trochlearis, spina trochlearis, trochlea, vagina m.o.b.s./

• m. levator palpebrae sup. (pars spf.+prof.)• n. III – other 5 muscles

• smooth svaly: m. orbitalis Mülleri, m. tarsalis sup. Mülleri + inf.© David Kachlík 30.9.2015

Movements of the eye-Movements of the eye-ball I.ball I.

movements around axis = ductions

• around vertical axis:– adduction (internal)– abduction (external)

• around horizontal axis: – elevation (sursumduction; supraduction): up– depression (deorsumduction; infraduction):

down

• around sagittal (antero-posterior) axis:– intorsion (incykloduction): tilted internally– extorsion (excykloduction): tilted externally© David Kachlík 30.9.2015

Movements of the eye-ball Movements of the eye-ball II.II.

paired movements (both eyes working together)• simultaneous movement of both eyes in the same

direction = version (conjugate movements) – dextroversion (to the right) + levoversion (to the left)– supraversion (sursumversion) + infra/deorsumversion (up + down)– dextro/levoelevation + dextro/levodepression (up/down and to

side)– dextro/levocykloversion (rotation to the right/left)

• simultaneous movement of both eyes in opposite directions = vergence (disconjugate movements), convergence = both eyes moving nasally or inward , divergence = both eyes moving temporally or outward

• strabismus; heterotropia; squint = one eye constantly is turned inward (“crossed-eye”), outward (“wall-eye”), upward, or downward. http://www.tedmontgomery.com/the_eye/eom.html


Movements of the eye-ball


Strabismus concomitans

• esotropia (s. convergens)

• exotropia (s. divergens)

• hypertropia (s. sursumvergens)

• hypotropia (s. deosumvergens)


Development of visual system

• neuroectoderm of the forebrain

• superficial ectoderm of head

• mesoderm in between

• cells from neural crest



• primordia from beginning of 4th week (22nd day)

• formation of optic grooves in the region of forebrain

• grooves deepen in optic vesicles• formation of optic peduncle• induction of ectoderm = thickening• formation of lens (optic) placode



• envagination of lens (optic) placode

• formation of hollow lens vesicle without connection to the external surface

• optic vesicles envaginate = optic cup

• envagiantion of optic pedicle and cup + migration of vascular mesenchyme = formation of vitreous vessels


Development of retina

• origin from optic cup

• external layer – pigment epithelium

• internal layer – proliferates into pars nervosa

• intraretinal space – successively fades out

• inversion of retina


Development of n. II

• fibres from ganglionic cells growth through the optic pedicle

• fissure (evagiantion) fades out


Development of corpus ciliare

• protrusion of both layers of optic cup

• pigment epithelium – from external layer

• non-pigment epithelium – from internal layer

• ciliary canal – from optic cup cavity

• m. ciliaris and connective tissue – from mesenchyme


Development of iris

• margin of eye cup

• external layer – smooth muscles

• internal layer –pigment epithelium


Development of lens

• from lens (optic) vesicle– anterior surface – no

change = epithelium anterius

– posterior surface – cells elongate as far as lumen disappers

• formation of primary fibres• secondary fibres – derived

from epitheliuum anterius cells

– capsula lentis – thickened BL of epitheliuum anterius

• a. hyaloidea – fades out• pupillary membrane –

covering lens – fades out© David Kachlík 30.9.2015

Development of camere bulbi

• camera anterior – fissure between primordial lens and cornea

• camera posterior – fissure in optic cup on sides of lens vesicle


Development of cornea, choroidea and sclera

• cornea– superficial ectoderm– mesenchyme– cells of neural crest

• choroidea and sclera– surronding mesenchyme


Development of palpebrae

• 6th week: cutaneous folds across cornea

• 10th week: both folds fuse

• 28th week: folds separate again

• inbetween: conjunctina adheres internally

• muscles: IInd branchial arch

• tarsus and glands from mesenchyme


Development of lacrimal glands

• evaginations of superficial ectoderm

• non-functionnal until 6th week– newborn does not water in eyes


finally…END !


Visual system Oculus et structurae pertinentes © David Kachlík 30.9.2015.

Documents

Transcript of Visual system Oculus et structurae pertinentes © David Kachlík 30.9.2015.