Eye

Transcription

Eye

Visual system
Oculus et structurae
pertinentes
© David Kachlík 30.9.2015
Odilo Redon
Orbita = Orbit
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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 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 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 structures
• medially: cellulae ethmoidales (via very
thin lamina orbitalis ossis ethmoidalis)
• caudally: sinus maxillaris
• cranially: fossa cerebri anterior
• dorsally: sinus cavernosus + fossa
pterygopalatina
Visual system
• bulbus oculi = eyeball
• structurae pertinentes oculi =
related structures of the eye
• topography: regio orbitalis
• development
Eyeball
• tunica fibrosa
(externa)
• tunica vasculosa
(media)
• tunica interna
(nervosa)
• corpus vitreum
(vitreous body) +
lens
Eyeball
• polus anterior,
posterior
• equator x meriadiani
• axis bulbi externus,
internus
• axis opticus (= „linea
visus“)
Tunica fibrosa (externa)
• sclera
• cornea
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)
Cornea
• perfectly transparent, non-vascular
• limbus, vertex
• 5 layers
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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
= 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
= Corpus ciliare
• annular shape,
triangular profile
• processus + plicae
ciliares
• orbiculus (external
part), corona
(internal part)
• smooth musculus
ciliaris
– fibrae meridionales,
radiales, circulares,
longitudinales
= 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
= Iris
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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)
= 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
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
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
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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
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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© David
to the
Kachlíkchoroidea
30.9.2015
Humor aquosus
= Aqeous humor
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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
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
© David Kachlíkparasympatheticolytics
30.9.2015
in
OCT
Optic
coherent
tomograph
y
measurement
s of light
reflexion
Break
Tunica interna (nervosa)
= Retina
• pars caeca
– pars iridica
– pars ciliaris
• ora serrata
• pars optica – 11 layers
– pigment part
– sensory part
Retina – pigment part
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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,
© David Kachlík 30.9.2015 discs
degradation of membranous
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
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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
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
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
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
Supporting cells
• Müller´s cells
– macroglia
– their BL = membrana limitans interna
– zonulae adherentes with rods and cones
• = membrana limitans externa
Layers of optic part of retina
• 11 layers
!!!  do not be frightened  !!!
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.)
David Kachlík 30.9.2015
– stratum limitans© internum
(10.)
Specific spots of retina
discus n. optici (= blind spot)
• n. II leaves the eyeball
• no light-sensitive cells
 excavatio disci
Specific spots of retina
• fovea centralis („macula
yellow spot“)
lutea;
–distant layers diverted laterally
–sharpest and most brilliant colour
vision spot
–cones only (100.000 cones)
 foveola (2500 cones)
OCT
Optic
coherent
tomograph
y
OCT
OCT
ABRUPTIO
RETINAE
Arterial supply of the eye
a. carotis interna  a. ophtalmica 
• aa. ciliares posteriores breves  choroidea
• aa. ciliares longae (24)  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
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
David Kachlík 30.9.2015
central vision and macula lutea
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 retinae
v. ophthalmica sup.  sinus cavernosus
v. ophthalmica inf.  plexus pterygoideus
v. angularis  v. facialis  v. jugularis int.
! danger of inflammation spreading !
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)
Nervus opticus
• evagination of diencephalon (thalamus
opticus)
• axons separated with endoneurium
• covered with meninges
• a. et v. centralis retinea runs inside the
nerve
VISUAL PATHWAY
Projection → Ascendent → Sensoric
4 - neuronal, partially crossed
1. neuron: rod and cones of retine
2. neuron: bipolar cells
3. neuron: ganglional cells  n. II  chiasma
opticum  corpus geniculatum laterale
4. neuron: cells in corpus geniculatum laterale 
tractus geniculocorticalis (= radiatio optica
Gratioleti)  lobus occipitalis, area 17 (around
sulcus calcarinus)
•
© David
Kachlík 30.9.2015
Meyer´s loop into
temporal
lobe
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
Structurae oculi accessoriae
= Related strctures of eye
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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
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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
Palpebrae = Eyelids
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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
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
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glandulae lacrimales accessoriae Krausei
rivus lacrimalis
lacus, papilla, caruncula lacrimalis
puctum, canaliculus lacrimalis
saccus lacrimalis  ductus nasolacrimalis
(plica lacrimalis Hasneri)  meatus nasi inf.
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.
Movements of the eyeball I.
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movements around axis = ductions
around vertical axis:
– adduction (internal)
– abduction (external)
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around horizontal axis:
– elevation (sursumduction; supraduction): up
– depression (deorsumduction; infraduction):
down
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around sagittal (antero-posterior) axis:
– intorsion (incykloduction): tilted internally
– extorsion (excykloduction):
tilted externally
Movements of the eye-ball
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”),
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. © David Kachlík 30.9.2015
deosumvergens)
Development of visual system
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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
© David Kachlík
• 30.9.2015
pupillary membrane –
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
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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 !


Eye

Transcription

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