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