This document provides an overview of the anatomy of the eyeball and its components. It discusses the three coats that make up the eyeball - the outer sclera and cornea, middle choroid, and inner retina. It describes individual structures like the iris, ciliary body, lens, vitreous body, as well as conditions like glaucoma, cataracts, retinal detachment, and more. The document is a lecture on ophthalmic anatomy from Professor Moira O'Brien of Trinity College Dublin.

2. MOB TCD
Eyeball
Professor Emeritus Moira O’Brien
FRCPI, FFSEM, FFSEM (UK), FTCD
Trinity College
Dublin

3. MOB TCD
Eyeball
• Surrounded by Tenon’s
fascia
• Attached to corneoscleral
junction
• Dura on optic nerve
• Check ligaments
• Suspensory ligament of
Lockwood
• Cone of muscles
• Fat

4. MOB TCD
Eyeball
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Consists of three coats
Outer layer
Sclera and cornea
Choroid
Retina

5. MOB TCD
Cornea
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Transparent
Avascular
Forms anterior 1/6
Smaller sphere than sclera
Depression at
corneoscleral junction

6. MOB TCD
Five Layers of Cornea
1. Corneal epithelium
2. Bowman’s or anterior
limiting membrane
3. Substantia propria
4. Descement’s or posterior
limiting membrane
5. Endothelium

7. MOB TCD
Cornea
• Posterior limiting
membrane breaks up at
the edges to form
pectinate ligament of iris
• Spaces are called the
spaces of the iridiocorneal
angle (fontana)

8. MOB TCD
Iridiocorneal Angle
• If the iridiocorneal angle is
narrowed
• Reabsorption of aqueous
humour into venous sinus of
sclera is blocked
• Causing glaucoma
• Blindness increased
intraocular pressure

9. MOB TCD
Cornea
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Cornea is avascular
Surface must be moist
Rheumatoid dry
Not wearing safety goggles
Scarring of cornea results
in blindness in that portion
of the cornea
• Trachoma, new vessel
formation in the cornea
• Transplants

10. MOB TCD
Sclera
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Posterior 5/6
Opaque
Insertion muscles
Vena vorticosae pierce at
equator
• Optic nerve 2.3 mm medial to
axis, the lamina cribrosa
• Central artery of retina
• Long and short cilary vessels
and nerves

11. MOB TCD
Suprachoroid Space
• Long ciliary nerves
• Long posterior ciliary
arteries going to iris

12. MOB TCD
Choroid
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Choroid proper
Ciliary body
Iris
Vascular layer in posterior
part
• Equator of eyeball
• Uveal tract or iridocyclitis

13. MOB TCD
Choroid
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Outer limiting membrane
Veins
Arteries
Capillaries
Inner limiting membrane of
bruch
• Attached to pigmented
layer of retina

14. MOB TCD
Ciliary Body
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Triangular
Apex posterior
Short base anterior
Deep surface thrown into
folds called the ciliary
processes
• Ciliary body is vascular,
pigmented

15. MOB TCD
Ciliary Zonule
• Suspensory ligament of lens
is attached to the cilary
processes
• The portion of the
suspensory ligament closest
to the ciliary
• Processes is called the
ciliary zonule

16. MOB TCD
Ciliary Muscles
• Smooth muscle
• Radial is attached to
scleral spur
• Circular within anterior
part of radial muscle
• Parasympathetic
oculomotor 3rd nerve
• Relays in ciliary ganglion

17. MOB TCD
Accommodation Reflex
• Contraction of ciliary
muscles
• Ciliary processes pulled
anteriorly
• Relaxes suspensory
ligament of lens
• Elasticity of lens
• It becomes more convex
• Pupils constrict
• Medial rectus contracts

18. MOB TCD
Iris

19. MOB TCD
Iris
• Cone shaped diaphragm
• Halfway along anterior of
base of choroid
• Central aperture pupil
• Vascular pigmented
• Amount pigment colour
• Blood vessels long
posterior, anterior cilary
arteries; two circles

20. MOB TCD
Iris
• Circular sphincter pupillae
• Oculomotor
• Behind lies radial or dilator
pupillae
• Sympathetic T1 develop
from ectoderm

21. MOB TCD
Aqueous Humour
• Aqueous humour is secreted
by ciliary processes into
posterior chamber
• Through the pupil into anterior
chamber
• Spaces of fontana into venous
sinus of sclera or canal of
Schlemn

22. MOB TCD
Posterior Chamber
• Bounded posteriorly by
suspensory ligament of lens
and lens
• Peripherally by ciliary
processes
• Anteriorly by iris

23. MOB TCD
Anterior Chamber
Anterior Chamber
• Bounded posteriorly by iris and
pupil
• Anteriorly by cornea
• Peripherally by spaces of
fontana or iridio-corneal angle

24. MOB TCD
Retina
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Nervous layer
Superficial to deep
Pigment cells
Rods and cones
Bipolar cells
Ganglion cells
Axons of the ganglion cells
form optic nerve

25. MOB TCD
Rods
• Rods are found at
peripheral portion of the
retina
• 70 rods connected to one
bipolar cell
• Peripheral vision
• Visual purple sees back and
white

26. MOB TCD
Cones
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Cones see colour
Photoreceptors
One cone to one bipolar cell
Found in fovea or macula
lutea
• Directly behind axis
• No nerve fibres or vessels
in front

27. MOB TCD
Blood Supply of Retina
• Rods and cones supplied
by capillaries of choroid by
diffusion
• Bipolar and ganglion cells
supplied by central artery of
the retina
• Enters through optic disc,
blind spot

28. MOB TCD
Optic Disc

29. MOB TCD
Diabetic Hypertensive

30. MOB TCD
Detached Retina
• Outer layer of optic cup
• Pigmented layer
• Inner layer
rods and cones
• Removed from their blood
supply

31. MOB TCD
Refractive Media
• Cornea
• Aqueous humour of anterior
and posterior chamber
• Lens
• Vitreous body

32. MOB TCD
Refractive Media
• Greatest refraction of light
• Takes place at the surface
of the cornea
• Very little refraction after
cornea

33. MOB TCD
Lens
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Crystalline
Translucent
Avascular structure
Lies in hyloid fossa
Posterior surface is highly
convex
• Does not alter its shape

34. MOB TCD
Lens
• Suspensory ligament is
attached to periphery of the
lens
• Cataract opaque lens
• Nutrition from aqueous
humour

35. MOB TCD
Lens
• Supplied by hyloid
• Artery during development
• Hyloid artery regresses
remains as the hyloid canal
• May persist, result a form of
blindness

36. MOB TCD
Vitreous Body
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Semiliquid
Translucent
Avascular gel
Enclosed in hyloid membrane
Opacities may develop in
elderly

37. MOB TCD
Subconjunctival Haemorrhage

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