understand basic eye anatomy for undergraduates.ppt

Ocular Anatomy S.Khairallah, M.D. 1
OCULAR ANATOMY
OCULAR ANATOMY
• GLOBE (EYE BALL)
• CONJUNCTIVA & EYELIDS
• LACRIMAL SYSTEM
• EXTRAOCULAR MUSCLES
• NERVES
• ORBIT

THE GLOBE(EYEBALL):
THE GLOBE(EYEBALL):
• TOPOGRAPHY & OPTICAL SYSTEM
• LAYERS(COATES)
• CHAMBERS
• LENS & ZONULES

THE EYEBALL,cont’d:
• TOPOGRAPHY & OPTICAL SYSTEM:
Axial length ..24 mm.
Equator ..16 mm.posterior to limbus
Diopteric power:
cornea … 40 D
lens … 20 D

THE GLOBE(EYEBALL):
THE GLOBE(EYEBALL):
• LAYERS(COATES)
• CHAMBERS
• LENS & ZONULES

COATES OF EYE
COATES OF EYE
OUTER
OUTER MIDDLE
MIDDLE
“Uveal tract”
INNER
INNER
CORNEA IRIS RETINA
LIMBUS CILIARY
BODY
_____
SCLERA CHOROID _____

OUTER COATE (LAYER):
• PRECORNEAL TEAR FILM
• CORNEA
• SCLERA
• LIMBUS

PRECORNEAL TEAR FILM:
• THREE LAYERS:
– Outer most : lipids …Meibomian , Zeiss
and Moll glands
– Middle : aqueous(watery) …Lacrimal and
accessory lacrimal glands
– Inner most : mucinous(mucoid) …Goblet
cells

• FUNCTIONS:
– Optical clarity
– Nutrition
– Defense mechanism

• CORNEA
• SCLERA
• LIMBUS

CORNEA :
CORNEA :
• THREE LAYERS:
– Epithelium / Bowman’s membrane
– Stroma
– Endothelium / Descemete’s membrane
• DIAMETER : 12 mm.Horiz. / 11 mm.Vertic.
• NERVE : Trigeminal,nonmylinated
• BLOOD SUPPLY: NONE “AVASCULAR”

• CORNEA
• SCLERA
• LIMBUS

SCLERA :
SCLERA :
• THREE LAYERS :
– Episclera
– Stroma
– Lamina fusca
• TWO OPPENINGS : anterior & posterior
• THICKEST ..1 mm. , THINNEST..0.3mm
• NERVES : anterior;long ciliary n.
posterior;short ciliary n.
both:sensory from trigeminal n.:
EXTREMELY PAINFULL WHEN INFLAMMED
EXTREMELY PAINFULL WHEN INFLAMMED

SCLERA,cont’d:
• BLOOD SUPPLY:
– Episclera & choroidal vesseles.
– Anterior to recti muscle’s insertion:-
• Anterior ciliary arteries  ciliary injection
– Posterior to recti muscle’s insertion:-
• Posterior ciliary arteries
• LYMPHATICS :
• None

• CORNEA
• SCLERA
• LIMBUS

LIMBUS:
LIMBUS:
• It is corneo-scleral junction
• Covered by conj./Tenon’s capsule
• Aqueous humor drainage system
• Nerves:autonomic n.& sensory
from trigeminal n.
• Blood:ant.ciliary arteries&episcleral
vesseles

COATES OF EYE
COATES OF EYE
OUTER
OUTER MIDDLE
MIDDLE
“Uveal tract”
INNER
INNER
CORNEA IRIS RETINA
LIMBUS CILIARY
BODY
_____

MIDDLE COATE:
MIDDLE COATE:
• =Uveal tract (uvea = grape (‫عنب‬
• 3 parts :
ANTERIOR INTER-
MEDIATE
POSTERIOR
IRIRS CILIARY
BODY
CHOROID

IRIS (
IRIS (:(
:(‫القزحية‬
‫القزحية‬
• It has a central hole (pupil) to control light
entering the eye ( ↓ glare)
• It’s thinnest at its insertion to Ciliary Body!
(traumatic iris dialysis)
• Two layers: anterior  stroma
posterior  epithelium
• Two muscles: sphincter pupillae m.(para.n.)
dilator pupillae m.(sym.n.)

IRIS,
IRIS,cont’d:
• Blood : major arterial circle of iris
• Nerve : sensory,nasociliary n.(5th
C.N.)

CILIARY BODY:
CILIARY BODY:
• It’s a triangular organ,base forward
• Two portions: uveal & epithelial
– Uveal portion:3 muscles;longitudinal,radial
and circular
– Epithelial portion:pars plicata & pars plana
• Blood:majot arterial circle of iris
• Nerve:short ciliary nerves

CHOROID:
CHOROID:
• It’s posterior part of uveal tract
• It’s 3 vascular layers , inner most :
choriocapillaris
• Blood: anterior & post. Ciliary arteries ,
drainage via vortex veins
• Nerve : short ciliary nerves

COATES OF EYE
COATES OF EYE
OUTER
OUTER MIDDLE
MIDDLE
“Uveal tract”
INNER
INNER
CORNEA IRIS RETINA
LIMBUS CILIARY
BODY
_____

Eyeball,INNER COATE:
INNER COATE:
• RETINA :
– Two major layers:
• Retinal pigment epithelium ( RPE) .. Outermost
• Neuro-sensory retina .. Innermost :
– Subdivided into 10 layers :
» Photoreceptors (rods,cones) … outermost
» Nerve fiber layer … innermost
– Centrally : Macula , fovea , foveola
– Blood : choriocapillaris & central retinal artery
– Functions :

THE GLOBE(EYEBALL):
THE GLOBE(EYEBALL):
• LAYERS(COATES)
• CHAMBERS
• LENS & ZONULES

Eye,CHAMBERS:
CHAMBERS:
ANT.CHM. POS.CHM VIT.CAVIT
Anteriorly Cornea Iris L.,zon.,CB
posteriorly Iris,lens Ant vit face Ret.,opt.n.
Laterally A/c angle Cil process Retina
medially --- Lens equato ---
volume 0.20 ml 0.06 ml 4.50 ml
Filled by Aqueous h. Aqueous h. Vitreous h.

Anterior chamber ANGLE:
Anterior chamber ANGLE:
• Between peripheral cornea & iris root
• ANGLE STRUCTURES: anterior to posterior
– Schwalbe’s line
– Trabecular meshwork  Schlemm’s canal
– Scleral spur
• FUNCTION : Drainage of aqueous humor

THE GLOBE(EYEBALL):
THE GLOBE(EYEBALL):
• LAYERS(COATES)
• CHAMBERS
• LENS & ZONULES

Eyeball , LENS:
LENS:
• Biconvex,transparent,colorless
• No vesseles,no nerves
• Held in position by zonules
• 10 mm.in diameter,4 mm.thick
• Consist of :
– Lens capsule
– Anterior lens epithelium
– Lens substances: cortex(new f.)&nucleus(old f.)

LENS ..cont’d:
LENS ..cont’d:
• Lens suture lines:ant.”y”,post.inverted”y”
• Contains 65% water , 35% proteins , trace
minerals ,↑ K+ ,ascorbic acid and
glutathione.
• AGING:
– Larger
– Harder(less elastic)
– Coloring: yellow  deep brown.why?

ZONULE :
ZONULE :
• = Zonule of Zinn , suspensory ligament
• Collagen fibrils
• Attach to nonpigmented epithelium of
ciliary body and either sides of lens
equator

OCULAR ANATOMY
OCULAR ANATOMY
• LACRIMAL SYSTEM
• NERVES
• ORBIT

‫اليك‬ ‫أتوب‬ ‫و‬ ‫اللهم‬ ‫استغفرك‬.. ‫وبحمدك‬ ‫اللهم‬ ‫سبحانك‬

understand basic eye anatomy for undergraduates.ppt

More Related Content

Similar to understand basic eye anatomy for undergraduates.ppt

More from QusaiAbusleem1

Recently uploaded

understand basic eye anatomy for undergraduates.ppt