stefan sivkov, md, phd. development А. onset 22 day of gestation; from neuroectoderm, ectoderm...
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Stefan Sivkov, MD, PhDStefan Sivkov, MD, PhD
DevelopmentDevelopment
А. Onset 22 day of gestation; from neuroectoderm, ectoderm & mesoderm.
B. Diencephalic vesicle gives origin to optic vesicle; after invagination develops double-layered optic cup.
i) Inner layer develops into в pars nervosa of retina
ii) Outer layer gives pars pigmentosa of retina, pigmentous epithelium of iris and ciliary body.
C. Ectoderm gives origin of :i) Lens.ii) Corneal epithelium and conjunctiva.
D. Mesoderm gives origin of: i) Stroma of sclera and cornea. ii) Stroma of choroid.
DevelopmentDevelopment
Three partsThree parts
Optic apparatusOptic apparatus – – controls the light entering the eyecontrols the light entering the eye
Detector systemDetector system – for black / white and color vision – for black / white and color vision
Nerve pathwaysNerve pathways – – conveys signals to brainconveys signals to brain
3 coats3 coats
Tunica FibrosaTunica Fibrosa: : cornea, scleracornea, scleraTunica VasculosaTunica Vasculosa: : choroidea, corpus ciliare, irischoroidea, corpus ciliare, irisTunica NervosaTunica Nervosa: : retinaretina
3 chambers3 chambers
Anterior eye chamber Anterior eye chamber Posterior eye chamberPosterior eye chamberCorpus vitreumCorpus vitreum
Eye ballEye ball
Tunicae bulbi
Outer, tunica fibrosa bulbi
- cornea (transparent) - sclera (non-transparent, bluish in children, yellowish in adults)
Middle, tunica vasculosa bulbi
- iris and central opening, рupilla - corpus ciliare composed of: musculus ciliaris, processus ciliaris, zonula ciliaris with fibrae zonulares & spatia zonularia - choroidеа
Inner, tunica interna bulbi (retina)
- blind part, рars caeca retinae (from мargo pupillaris iridis to оra serrata): Pars iridica retinae (double-layered, pigmented cells) Pars ciliaris retinae (double-layered, pigmented inner layer) - рars optica retinae (stratified)
Eye chambersEye chambers
Three chambers filled with fluidThree chambers filled with fluid::
Camera aCamera anterior nterior bulbibulbi ( (betweenbetween cornea cornea && iris), iris),
Camera Camera рosterior рosterior bulbibulbi ( (betweenbetween iris, fib iris, fibraerae zonul zonulareare && lenslens) )
Corpus vitreumCorpus vitreum ( (between lens &between lens & retinaretina). ).
The nfirst two filled withThe nfirst two filled with humor aquohumor aquossusus,,
Corpus vitreumCorpus vitreum filled withfilled with humorhumor vitreus vitreus..
Tunica fibrosaTunica fibrosa
ScleraSclera
PosteriorPosterior 4/5 4/5 of tunica fibrosaof tunica fibrosa; ;
Collagen & elastic fibersCollagen & elastic fibers, , fibroblastsfibroblasts ( (substantia substantia
propria scleraepropria sclerae), ),
3 3 layerslayers::
episcleraepisclera: : outerouter
substantia propria scleraesubstantia propria sclerae: : middlemiddle
lamina fuscalamina fusca: : innerinner, , collagen & elastic fiberscollagen & elastic fibers
pigment cellspigment cells; ; borders choroidborders choroid
CorneaCornea
А. Anterior 1/5 of the coatБ. 5 – layered: - Epithelium anterius: squamous stratified
nonceratizing, 5 - 6 layers:- Lamina limitans anterior (Bowman): 7 -12 mcm,
collagen fibers, lacks cells, barrier agains infection, does not regenerates.
- Substantia prоpria: 200 laminae of parallel collagen fibers.
- Lamina limitans posterior (Descemet): 5 - 10 mcm, basal lamina of endothelium.
- Endothelium posterius: simple squamous epithelium
i) Avascular
ii) Transparent
iii) Limbus - connection with sclera:
Highly vascular
Contains sinus venosus sclerae
(Schlemm canal)
Tunica vasculosaTunica vasculosa
Three partsThree parts::
11. . PosteriorPosterior - с - сhoroideahoroidea
2. 2. MiddleMiddle - с - сorpus ciliareorpus ciliare
3. 3. AnteriorAnterior - - irisiris
2/3 2/3 of the coatof the coat Attached posteriorly to the scleraAttached posteriorly to the sclera
– Spatium perichoroidaleSpatium perichoroidale– Lamina suprachoroideaLamina suprachoroidea
Composed ofComposed of::– Connective tissueConnective tissue– Pigment cellsPigment cells– Blood vesselsBlood vessels
3 3 layerslayers::– Lamina vasculosaLamina vasculosa – Lamina choriocapillarisLamina choriocapillaris – Lamina basalis (Bruch)Lamina basalis (Bruch)
ChoroideaChoroidea
ChoroideaChoroidea
Orbiculus ciliarisOrbiculus ciliaris – posterior – posterior Corona ciliarisCorona ciliaris - - anteromedialanteromedial
– Processus ciliares (70-80)Processus ciliares (70-80) Dense capillary networkDense capillary network ProduceProduce humor aquosushumor aquosus Fibrae zonularesFibrae zonulares
Musculus ciliarisMusculus ciliaris - - laterallateral Fibrae meridionales (Brucke)Fibrae meridionales (Brucke) Fibrae radialesFibrae radiales Fibrae circulares (Muller)Fibrae circulares (Muller)
– Takes part inTakes part in ( (n. oculomotoriusn. oculomotorius))
Corpus ciliareCorpus ciliare
Coprpus ciliareCoprpus ciliare
OOrbiculus ciliaris, corona ciliarisrbiculus ciliaris, corona ciliaris
AccomodationAccomodation
Focusing for near visionFocusing for near vision
Contraction of the pupilContraction of the pupil
ConvergenceConvergence
AccomodationAccomodation
M. ciliarisM. ciliaris contractscontracts and and
moves forwardmoves forward
ThatThat relaxesrelaxes zonule zonule ciliares ciliares
and lens becomes more and lens becomes more
convexconvex
The eye adapts to near visionThe eye adapts to near vision
IIrisris
Color is genetically determinedColor is genetically determined. .
PigmentPigment: :
а. а. melaninmelanin && bb. . lipochromelipochrome..
MelaninMelanin - - genegene ofof 15 15 chromosome.chromosome.
LypochromeLypochrome - - genegene ofof 19 19 chromosomechromosome. .
IrisIris
Anterior partAnterior part Opening in the middleOpening in the middle, , pupillapupilla.. Margo pupillaris &Margo pupillaris & margo ciliarismargo ciliaris Annulus iridis minor &Annulus iridis minor & anulus iridis majoranulus iridis major StructureStructure
– Epithelium anteriusEpithelium anterius– Stroma iridisStroma iridis– M. sphincter & dilatator pupillaeM. sphincter & dilatator pupillae– Epithelium pigmentosumEpithelium pigmentosum
Attached to the sclera byAttached to the sclera by lig. pectinatumlig. pectinatum
IIris. Ligamentum pectinatumris. Ligamentum pectinatum
RetinaRetina Eye fundusEye fundus discus nervi opticidiscus nervi optici (2 x (2 x
1.5 mm), 1.5 mm), centralcentral - - excavationexcavation. . 4 mm 4 mm lateral islateral is an oval spotan oval spot, , foveafovea, ,
in the center ofin the center of macula macula lutealutea.. Centarl part of retinaCentarl part of retina – d=– d=21 mm 21 mm
from the center offrom the center of discus ndiscus n.. optici optici . . Diameter of retina -Diameter of retina - 42 mm. 42 mm.
StructureStructure
RetinaRetina ((0.5 mm0.5 mm)) inner layerinner layer..
N. opticusN. opticus – – axons of the ganlion cellsaxons of the ganlion cells..
Ganglion cellsGanglion cells, , efferent, the innermostefferent, the innermost. .
Photoreceptive cells, rod and cones,Photoreceptive cells, rod and cones, outerouter. .
1. 1. Pars pigmentosaPars pigmentosa - - detachment of retinadetachment of retina
2. Pars nervosa2. Pars nervosa
(1) Stratum neuroepitheliale(1) Stratum neuroepitheliale
Bacillus, ConusBacillus, Conus
(2) Stratum nucleare externum(2) Stratum nucleare externum Bipolar cellBipolar cell Horizontal cellHorizontal cell Amacrine cellAmacrine cell
(3) (3) Stratum nucleare internumStratum nucleare internum Ganglion cellGanglion cell NervusNervus Opticus (II)Opticus (II)
RETINARETINA
Three cellular layersThree cellular layers
Outer nuclearOuter nuclear – – bodies ofbodies of rods & conesrods & cones
Inner nuclearInner nuclear – – bodies of bipolar,bodies of bipolar,
horizontal & amacrine cellshorizontal & amacrine cells
GanglionGanglion – – bodiesa of ganglion cellsbodiesa of ganglion cells. .
Two synaptic layersTwo synaptic layers
Outer plexiformOuter plexiform
Inner plexiformInner plexiform
Structure of retinaStructure of retina
Stratum plexiforme Stratum plexiforme externumexternum
Stratum plexiforme Stratum plexiforme internuminternum
Synaptic layersSynaptic layers
Ora serrataOra serrata. . Pars opticaPars optica && pars ceca retinaepars ceca retinae
Fovea centralisFovea centralis
Rods and conesRods and cones
Optic nerveOptic nerve
Visual Visual
PathwayPathway
Modality: Modality: Vision Vision Receptor: Receptor: Photoreceptor Cell of RetinaPhotoreceptor Cell of Retina Cranial Nerve: II (Optic nerve)Cranial Nerve: II (Optic nerve)
1st Neuron:1st Neuron: Bipolar CellBipolar Cell 2nd Neuron: 2nd Neuron: Ganglion CellGanglion Cell optic nerveoptic nerve optic chiasmoptic chiasm optic tractoptic tract 3rd Neuron: 3rd Neuron: Lateral Geniculate Nucleus Lateral Geniculate Nucleus optic radiationoptic radiation Termination: Termination: Primary Visual Area (V I)Primary Visual Area (V I) Brodmann area 17Brodmann area 17
Modality: Modality: Vision Vision Receptor: Receptor: Photoreceptor Cell of RetinaPhotoreceptor Cell of Retina Cranial Nerve: II (Optic nerve)Cranial Nerve: II (Optic nerve)
1st Neuron:1st Neuron: Bipolar CellBipolar Cell 2nd Neuron: 2nd Neuron: Ganglion CellGanglion Cell optic nerveoptic nerve optic chiasmoptic chiasm optic tractoptic tract 3rd Neuron: 3rd Neuron: Lateral Geniculate Nucleus Lateral Geniculate Nucleus optic radiationoptic radiation Termination: Termination: Primary Visual Area (V I)Primary Visual Area (V I) Brodmann area 17Brodmann area 17
Visual PathwayVisual Pathway Visual PathwayVisual Pathway
1. Optic nerve1. Optic nerve
2. optic chiasm2. optic chiasm
3. optic tract3. optic tract
4. lateral geniculate body4. lateral geniculate body
5. optic radiation5. optic radiation
6. visual cortex6. visual cortex
(striate cortex)(striate cortex)
7. Meyer’s loop7. Meyer’s loop
8. lateral ventricle8. lateral ventricle
Visual PathwayVisual Pathway
1. Optic nerve1. Optic nerve
2. Optic chiasm2. Optic chiasm
3. Optic tract3. Optic tract
4. Lateral geniculate 4. Lateral geniculate
bodybody
5. Optic radiation5. Optic radiation
6. Visual cortex6. Visual cortex
(Striate cortex)(Striate cortex)
Visual Visual PathwayPathwayVisual Visual
PathwayPathway
Clinical Features of Visual Pathway LesionClinical Features of Visual Pathway Lesion Clinical Features of Visual Pathway LesionClinical Features of Visual Pathway Lesion
1. optic nerve1. optic nerve
2. optic chiasm2. optic chiasm
3. optic tract3. optic tract
4. 5. optic radiation4. 5. optic radiation
A. unilateral blindnessA. unilateral blindness
B. bitemporal hemianopsiaB. bitemporal hemianopsia
C. left homonymousC. left homonymous hemianopsiahemianopsia
D. left inferior homony-D. left inferior homony- mous quadranopsiamous quadranopsia
E. left superior homony-E. left superior homony- mous quadranopsiamous quadranopsia