This document provides an overview of the anatomy, nerve and blood supply of the uvea, which includes the iris, ciliary body, and choroid. It begins with an introduction to the uvea and its embryological development. It then discusses the anatomy and structures of the iris, ciliary body, and choroid in detail. It also reviews the blood supply and some clinical applications related to the uvea. The document is presented as part of an optometry lecture covering this topic in detail over several slides.

1. UVEA: ANATOMY, NERVE &
VASCULAR SUPPLY, CLINICAL
CORRELATION
Presenters:
Suraj Thapa Magar
Sarmila Acharya
2nd year
B.Optometry
Resource person:
Mr. Niraj Dev Joshi

2. Presentation Layout
1) Introduction
2) Embryology of the Uveal tract
3) Congenital anomalies of Uveal tract
4) Iris: anatomy and nervous supply
5) Ciliary body: anatomy and nervous supply
6) Choroid: anatomy
7) Blood supply of Uveal tract
8) Clinically applied aspects
9) References

3. • Coined from latin word uva - grape
• Middle vascular coat of eyeball
• From anterior to posterior:
- Iris
- Ciliary body
- Choroid
INTRODUCTION

4. Uveal tract firmly attached to sclera only at 3 sites
• The scleral spur
• The exit points of vortex veins
• The optic nerve

5. Embryology
NEUROECTODERM
 Epithelial layers of the iris
 Sphincter and dilator pupillae muscles
 Epithelial layers of the ciliary body
PERIOCULAR MESENCHYME
 Blood vessels of iris, choroid, ciliary
body
 Stroma of iris
 Ciliary muscle and stroma of ciliary body
 Choroid

6. Milestones
9th week of gestation Ciliary body begins to appear
12th week of gestation Sphincter pupillae appears
4th month Ciliary processes fully formed
5th month Iris and choroid are formed
6th month Dilator muscles begin to form
Sphincter muscle fully differentiated
Postnatal period dilator muscles reach adult
proportion by 5 years

7. Sometimes strands of
this tissue are left as
Persistent pupillary
m/m
Towards end of gestation , the central iris stroma
(pupillary m/m) disappears forming pupil.
-Represents remnants of vascular sheath of lens
-Strands arise from and insert into iris collarette.
The dilator muscle is not apparent until sixth month, and
differentiation of myoepithelial cells continues after
birth→pupillary miosis

8. Congenital Anomalies of Uveal Tract
Aniridia
 Partial or complete absence of iris
 True aniridia : rare
 A peripheral rim of iris present (although hypoplastic)
& this is called clinical aniridia

9. Heterochromia of iris
Heterochromia Iridium Heterochromia Iridis
Color of one iris differs from
the other
One sector of iris differs
from the remainder of iris

10. Corectopia
• Displacement of pupil
• Bilateral and symmetric
• A/w ectopia lentis, and the
lens and pupil are commonly
dislocated in opposite
directions
Polycoria
• More than one opening in the
iris
• Result of local hypoplasia of
iris stroma and pigment
epithelium

11. Colobomas
 Colobomas represent an absence of tissue
 may occur anywhere along optic fissure and can affect
the iris, choroid, macula & optic nerve
Because optic fissure closes first at equator of eye, & then in a
posterior and anterior direction, colobomas are most frequently
found at the two ends of the optic fissure, i.e iris and optic nerve
Generally Choroidal /Fetal Fissure Closes by 6th wk of gestation
Failure to fuse results typical COLOBOMAS

12. Uveal coloboma
- Coloboma : a condition where a portion of the structure is
missing
Typical coloboma:
Located inferonasally in
the region of closure of
embryonic fissure
a. Complete coloboma:
Extends from pupil to optic
nerve Includes retina, choroid,
ciliary body, iris
b. Incomplete coloboma:
Involve the iris alone, or iris and
ciliary body, or iris, ciliary body
& part of choroid

13. Atypical coloboma
- Occasionally found in other positions i.e. not related to
fissure closure
- It is usually incomplete

14.  Greek Word iris - color haloes/rainbows
 Anterior most part of uvea
 Diameter -12 mm
 Thickness -0.5 to 0.6 mm
 3 to 4 mm aperture slightly nasally-
pupil
 Attached to middle of anterior surface
of ciliary body
 Thinnest at root and tears easily away
from its attachment to ciliary body :
Iridodialysis
IRIS

15. POINTs TO BE NOTED
Pupillary margin
rests lightly on
anterior surface of
lens so when lens is
removed iris is flat
and often tremulous:
IRIDODONESIS
CYCLODIALYSIS is
separation of ciliary body
from scleral spur, creating
a direct connection
betwn anterior chamber
and suprachoroidal
space
increases aqueous
outflow and predisposes
the eye to hypotony

16. Macroscopic structure
Anterior surface
1. ciliary zone:
- radial steaks
- crypts: peripheral & central
- contraction furrows
2. Pupillary zone: between collarette and pigmented
pupillary frill

18. Posterior surface
- dark brown or black
- looks smooth
Under Magnification:
-schwalbe’s contraction folds:
radial furrows, commence 1mm from pupillary border
-schwalbe’s structural furrows:
start 1.5mm from pupillary border, narrow and deep to
start with but becomes wide and shallow as they approach the
ciliary margin
-circular furrows:
finer than radial furrows
cross the structural furrows at regular interval
more marked near the pupil

19. Contact between the posterior surface of iris
and anterior capsule of the lens is also altered
by pupillary size
It is greatest on mid dilatation
Precipitate angle closure glaucoma in some
predisposed eye with narrow angle

20. Microscopic structure
1. Anterior limiting layer
2. Iris stroma
3. Anterior epithelial layer
4. Posterior pigmented epithelial layer

21. 1. Anterior limiting membrane
• Condensed part of the stroma
• Consists of melanocytes and fibroblasts
• Deficient in areas of crypts, very thin at contraction
furrows
• Determines the color of iris
3 types of intercellular junctions present
- Gap junctions
- Intermediate junctions
- Discontinuous tight junctions

22. 2. Stroma
• Main bulk of iris tissue
• Consists of loosely arranged collagenous network
with mucopolysaccharide ground substance
contains
-The sphincter pupillae muscles
- Dilator pupillae muscles
-The vessels and nerves of iris
-Cellular elements: fibroblast, melanocytes, clump
cells and mast cells

23. Sphincter pupillae muscles
- 0.7mm wide , 0.1-0.17mm thick
- Encircles pupillary margin
- lies in stroma deep to the surface
- -
Even after broad iridectomy , which removes a sector of iris
sphincter,the remaining sphincter can still constrict the remaining
pupil margin
Origin is from anterior epithelium,but actually
separated from this layer by a thin sheet of collagen
& dilator fibre processes, to which it is firmly bound.
-Innervated by parasympathetic via short ciliary nerve

24. Dilator pupillae muscle
- 60um long &7um wide
- Filled with myofilaments
- Extend from iris root towards pupil
- When the muscle contract,it pulls the pupillary
margin towards the ciliary body, dilating the pupil
- Innervated by sympathetics via long ciliary nerve

25. Parasympathetic Control of pupillary Size
Sphincter Pupillae
Short ciliary Nerve
Ciliary Ganglion
Inferior Oblique Muscle
Oculomotor Nerve
Edinger Westphal
Nucleus

26. Dilator muscle
Long ciliary nerve
Ciliary ganglion
Ophthalmic division of Vth nerve
Cervical ganglion
Ciliospinal centre of Budge
Posterior Hypothalamus
Sympathetic Control of Pupillary Size:

28. Blood vessels
- Form bulk of iris stroma
- They arise mainly from circulus arteriosis major
- Some also arise directly from anterior ciliary arteries
-Responsible for radial streaks seen on anterior surface
of iris
Peculiarities of Iris : Absence of internal elastic lamina
non fenestrated capillary endothelium

29. Cellular elements of stroma
1) Fibroblast
• Most common stromal cell
• Found around blood vessels, nerves, muscle
tissue and throughout the iris substance
2) Melanocytes
• Branching elements with processes
• Contain melanin granules

30. 3) Clump cells
• large round pigment cells without processes
• filled with inclusion granules
4) Mast cells
• They are round
• Have villous processes
Extracellular matrix of stroma
-Contain type VI collagen
-Laminin and fibronectin

31. 3. Anterior Epithelial Layer
• Anterior continuation of pigment epithelium of
ciliary body
• Lacking of melanocytes
• Basal processes of the cells of this layer give rise to
dilator pupillae muscle

32. 4. Posterior pigmented epithelial layer
• Anterior continuation of non pigmented
epithelium of ciliary body which in turn is the
continuation of sensory retina
• Contain abundant columnar type pigment cells
• It curves around the pupillary margin and extends
for a short distance onto anterior border layer of
iris stroma as the pigment ruff.

33. - presence of iris pigment epithelium on anterior
surface of iris
- Congenital or a/w rubeosis irides,
neurofibromatosis,etc
Clinical significance
Ectropion uveae

34. Forward bowing of iris
Angle closure glaucoma
Contact between the posterior surface of iris
and lens creates a relative pupillary block to the
flow of aqueous humor through the pupil,which
is more marked in mid dilatation

35. Applied anatomy
Iris Nodules
- Accumulated deposits of epithelioid cells and lymphocytes
deposited onto the iris without tissue destruction.
Two types:
Koeppes nodule at pupillary border Busaccas nodules near collarette

36. Iris Atrophy
- Areas of degeneration of iris
- Commonly seen in iridocyclitis

37. • Forward continuation of the choroid at ora serrata
• In cut section, triangular in shape
CILIARY BODY

38. • Anterior side of triangle- part of anterior chamber
angle
• In middle- attached to the iris
• Outer side of triangle- lies against the sclera with a
suprachoroidal space in between
• Inner side of triangle divided into 2 parts:
1) Pars plicata-anterior
2) Pars plana-posterior

39. 1) Pars plicata / corona ciliaris
• Anterior part
• About 2 to 2.5 mm long
• Contain ciliary muscles
• Have finger like ciliary processes
2) Pars plana / orbicularis ciliaris
• Posterior smooth part
• 5mm wide temporally
• 3 mm wide nasally

41. Microscopic structure
From without inwards, consists of five layers:
1) Supraciliary lamina
2) Stroma of the ciliary body
3) Layer of pigmented epithelium
4) Layer of non-pigmented epithelium
5) Internal limiting membrane

42. 1) Supraciliary lamina
• Outermost condensed part of stroma
• Consists of pigmented collagen fibres
• Continuation of suprachoroidal lamina
• Anteriorly, continues with the anterior limiting membrane of
iris
2) Stroma of the ciliary body
• Consists of collagenous connective tissue and fibroblast
• Embedded in it:
a. Ciliary muscle
b. Blood vessels
c. Nerves
d. Pigment cells & other cells

43. Ciliary muscle
• Non striated muscle
• Occupies most of the outer part of the ciliary
body
Three main groups:
1) The longitudinal or meridional fibres
2) The oblique or radial fibres
3) The circular fibres

44. 1) Longitudinal or meridional fibres
-Most external and closest to the sclera
-Pass posteriorly into the stroma of ciliary body
2) Oblique or radial fibres
-Radiate out from the
scleral spur
3) Circular fibres
-Occupy anterior and inner
portion of the ciliary body
-Nearest to the lens
-Runs parallel to the limbus
-Directly act as sphincter

45. Main action of all parts of ciliary muscles is to slacken
the suspensory ligament of lens & thus helps in
Accommodation.
-Longitudinal muscle fibres form tendinous attachment
to the scleral spur: their contraction increases aqueous
flow by opening up the spaces of trabecular meshwork

46. Contraction of the ciliary
muscle,especially longitudinal
and circular fibres pulls the
ciliary body forward in
accommodation.

47. Vascular stroma
-Contains major arterial circle just in front of circular
fibres
- Arterial circle is formed by the anastomosis between
the long posterior ciliary arteries and anterior ciliary
arteries and send branches to iris and ciliary body

48. 3) Layer of pigmented epithelium
• Forward continuation of RPE
• Anteriorly, continuous with anterior epithelium of
iris
4) Layer of non-pigmented epithelium
• Consists mainly of low columnar or cuboidal cells
• Forward continuation of sensory retina which stops
at ora serrata.
• Continues anteriorly with posterior pigmented
epithelium of the iris

49. 5) Internal limiting membrane
• Lines the non-pigmented epithelium
• Forward continuation of internal limiting membrane of
the retina.

50. Nerve supply of the ciliary body
• Sensory fibres run from the nasociliary branch of the
ophthalmic division of the trigeminal nerve, as the
long ciliary nerve
• These fibres enter the ciliary body and terminate in
iris, cornea and ciliary muscle
Sensory Nerves

51. Edinger
Westphal
nucleus
Autonomic Nerves
Parasympathetic fibres
Oculomotor
nerve
Accessory
Ganglion
Short ciliary
nerve
Ciliary
muscle

52. Ciliary processes
• Whitish finger-like projections
from pars plicata part of the
ciliary body
• 70 to 80 in number
• Each process is about
2mm long and 0.5mm in diameter
• Are the site of aqueous
production

53. Ultrastructure of ciliary processes
Consists of:
a. The network of capillaries
b. Stroma of ciliary
processes
c. Two layers of epithelium

54. a. The network of capillaries
• Occupies the centre of each process
• Each capillary consists of a very thin endothelium
with fenestration
• Lined by basement m/m
• Mural cells or pericytes present within basement
membrane

55. b) Stroma of the ciliary process
• Very thin
• Separates capillary network from epithelial layers
• Consists of ground substance: mucopolysaccharide,
proteins & solute of plasma
• Few collagen connective tissue fibres
• Wandering macrophages

56. c) Two layers of epithelium
• Their apical surfaces in apposition to each other
Outer pigmented epithelium:
• Contains numerous melanin granules
Inner non-pigmented epithelium:
• Contain mitochondria, zonula occludentes &
lateral and surface interdigitations
• The tight junction between cells of this layer form
blood aqueous barrier

58. • Posterior portion of the middle vascular coat
• Extremely vascular
• Extends from optic disc to ora serrata
• The inner surface: smooth, brown and lies in contact with
RPE
• The outer surface: rough and attached to sclera
• Posteriorly-0.22 mm thick
• Anteriorly-0.1 mm
CHOROID

59. • Firmly attached to the margin of the optic disc
• Loosely at points where vessels and nerves enter it
• Attachment to sclera is strongest

60. Microscopic Structure
From without inwards, consists of four
layers:
1) Suprachoroidal lamina
(lamina fusca)
2) Stroma of the choroid
3) Choriocapillaries
4) Bruch’s membrane
(basal lamina or lamina vitrae)

61. 1) Suprachoroidal lamina
• Thin membrane 10 to 34 μm
• Made of condensed collagen fibres, melanocytes
and fibroblasts
• Continues anteriorly with supraciliary lamina
• Space between this m/m and sclera: suprachoroidal
space (contain long & short posterior ciliary arteries
and nerves)

62. -Contains vessels, nerves, cells & connective tissue
-Stromal cells include:
a. Melanocytes
b. Fibrocytes
c. Macrophages
d. Mast cells
e. Plasma cells
2) Stroma of the choroid
Main bulk is formed by vessels, arranged in two
layers:
a. Haller’s layer: outer layer of large vessels
b. Sattler’s layer: inner layer of medium vessels

63. • Consists of a rich bed of wide bore fenestrated
capillaries (18 to 50μm)
• Receives most of its blood from medium & large
vessels of stroma
• Nourishes RPE & outer layers of sensory retina
• Density greatest at macula
3) Choriocapillaries
• Choriocapillaries are divided into non
overlapping lobules or hexagonal
patches

64. • Innermost layer of choroid
• Thin non cellular lamina
• Lies between
choriocapillaries and
pigment epithelium of
the retina
• 2 to 4 μm thickness
4) Bruch’s membrane

65. Comprises of five layers
a. Basal lamina of RPE
b. Inner collagen layer
c. Middle elastic layer
d. Outer collagen layer
e. Basal lamina of choriocapillaries

66. • Choroidal ischaemia often occurs as a pale hexagonal
patches (mosaic pattern)
• During choroidal phase of FFA, these lobules fill
independently from one another, giving a transiently
patched or blotched appearance
Clinical significance

67. Bruch’s membrane become thickened with
increasing age and produces hyaline
excrescence known as Drusens

68. Uveal tract supplied by 3 sets of arteries:
1) Short posterior ciliary arteries
2) Long posterior ciliary arteries
3) Anterior ciliary arteries
BLOOD SUPPLY OF THE UVEAL
TRACT

70. 1) Short posterior ciliary arteries
Arise as two trunks from the ophthalmic artery
Each trunk divides into 10 to 20 branches
Pierce the sclera around the optic nerve
Supply the choroid in segmental manner

71. 2) Long posterior ciliary arteries
Arise as nasal and temporal branch from the ophthalmic artery
Pierce the sclera obliquely on medial & lateral side of optic nerve
Run forward in suprachoroidal space to reach ciliary muscle,
without giving any branch
Anastomose with each other & with the anterior ciliary arteries to
form major arterial circle
And give branches which supply the ciliary body

72. 3) Anterior ciliary arteries
Derived from muscular branch of ophthalmic artery
7 in number: 2 each from arteries of SR, IR & MR, 1 from that
of LR
Pass anteriorly in the episclera
Give branches to sclera, limbus & conjunctiva
Ultimately pierce the sclera near the limbus to enter ciliary
muscle

73. Anastomose with two long posterior ciliary arteries to form
major arterial circle
Several Branches arise from major arterial circle & supply ciliary
process (one branch for each process)
Many branches from major arterial circle run radially through
iris towards pupillary margin
Anastomose with each other to form minor arterial circle

75. • Four in number
(superior temporal,
inferior temporal,
superior nasal and
inferior nasal)
• Pierce sclera obliquely
on each side of SR and
IR muscles about 6 mm
behind the equator
Venous Drainage
 Venae vorticosae
(vortex veins or posterior ciliary veins)

76. • Two superior vortex veins open into superior ophthalmic
vein
• Two inferior vortex veins open into inferior ophthalmic
vein

77. Uveitis:
Inflammation of Uveal tissue only
Classification:
1.Anterior uveitis:
Some Clinically Applied Aspects
Inflammation of Uveal tissue from iris upto pars plicata
of ciliary body
-Iritis: inflammation predominantly affect iris
-Iridocyclitis: iris and pars plicata part of ciliary body are
involved
-Anterior cyclitis: pars plicata part of ciliary body is
predominantly affected

78. 2.Intermediate Uveitis:
Inflammation of pars plana and peripheral
part of retina and underlying choroid
3.Posterior Uveitis:
 Inflammation of choroid and retina
Hence the term choroiditis, chorioretinitis,
retinochoroiditis or neurouveitis is used
4.Panuveitis:
Inflammation of whole uvea

80. Pain
Redness
Photophobia
Salient features of Uveitis

81. Posterior
synechiae
Cataract Glaucoma
due to PAS
Band
keratopathy
Posterior
synechiae
Cataract Glaucoma
due to PAS
Band
keratopathy
Complications of uveitis

82. Common clinical signs
a) Aqueous Cells:
-Presence of inflammatory
cells in the anterior chamber
-The inflammatory response causes white blood cells
such as neutrophils, monocytes and lymphocytes to
leave the inflamed iris vessels to reach aqueous
humour.

83. Aqueous Flare:
- Turbidity of the aqueous
humour caused by increased
protein level
- Blood aqueous barrier
breakdown results in protein (albumin) exudation in
the anterior chamber giving the normally clear,
colorless aqueous humour a milky appearance k/a flare