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2. UVEAL TRACT
Uvea known as middle
vascular coat of eyeball.
Anterior to posterior it can
be divided into three parts---
 Iris
Ciliary body
Choroid
Note– Uvea is a Greek
word meaning Grapes.

3. IRIS
 Anterior part of the uveal tract.
 Forms diaphragm like structure in front of lens.
 Center of iris has an 3-4 mm aperture called Pupil.
 At periphery it is attached to the anterior surface of ciliary
body.
 Divides the space between the cornea and lens into anterior
and posterior chamber.

5. TOPOGRAPHY OF IRIS
 Average diameter of the iris is 10 to 11 mm.
 The thickness of iris root is approximately 0.5
mm.
 It is thickest at collarette, which is located
approximately 1.5 mm from the pupillary
margin
 It is thinnest at iris root, the part of iris which
joins with the ciliary body

6. EMBRYOLOGY
 Both layer of epithelium is derived from marginal region of
optic cup. (Neuroectoderm)
 Sphincter and dilator pupillae muscle derived from anterior
epithelium . (Neuroectoderm)
 Stroma and vessels developed from vascular mesoderm
present anterior to optic cup.

7. MACROSCOPIC APPEARANCE
 Anterior surface—
Divided into cilary and pupillary zone by zigzag line called
collarette.
It is the thickest region of the iris which lies about 2 mm
from the pupil margin.

8. Cilliary zone-
It extend from the collarette to iris root.
There are some depressions or pit arranged in
rows present in this area known as crypts.
Crypts are found in two locations. Those
present near collarette are relatively larger and
known as Fuchs’s crypt and few are seen in
periphery of the iris
Pupillary Zone-
It lies between the collarette and pigmented
pupilary frill
It is 1.6 mm wide,relatively smooth and flat.

10. POSTERIOR SURFACE
Posterior surface of
the iris is much more
uniform.
Posterior surface of
the iris is darker than
the anterior surface and
shows numerous radial
contraction folds.

11. MICROSCOPIC STRUCTURE
Microscopically iris consist of four layers
1) Anterior limiting membrane.
2 Iris stroma
3 Anterior epithelium layer
4-- Posterior pigmented epithelium layer.

12. 1.Anterior limiting layer :
 It lines the iris and is the anterior most condensations of iris
stroma.
 The layer consist of mainly fibroblasts and melanocytes.
 Previously, this layer is known as ENDOTHELIAL LAYER .
 This layer is mainly responsible for the colouring action of iris.
2. Iris stroma:
Iris stroma forms the main bulk of iris tissue and contains
sphincter pupillae, dilator pupillae muscles, vessels and nerves.
3. Anterior epithelium layer :
It is the anterior continuation of the pigmented epithelium of
retina and ciliary body.
4. Posterior pigmented epithelium layer-
Anterior continuation of the non- pigmented epithelium of the ciliary body
and the sensory retina

14. CILIARY BODY
 It is the anterior portion of the uveal tract , which is
located b/w the iris and the choroid.
 middle part of vascular coat of eyeball.
 Triangular in shape.
 Inner side of triangle is divided into two parts.
 The anterior portion - pars plicata
 The posterior portion-pars plana
 The outer side of triangle lies against the
sclera.
 composed of muscles , vessels and epithelium.

17. EMBRYOLOGY
 Both epithelial layer of ciliary body develop from
the anterior part of the two layers of optic
cup.(neuroectoderm)
 Stroma of the ciliary body , ciliary muscle and blood
vessels are developed from the vascular layer of
mesenchyme surrounding the optic cup.

19. MICROSCOPIC STRUCTURE
🞭 Microscopically ciliary body consist of five layers.
o Supraciliary lamina.
o Stroma.
o Layer of pigmented epithelium.
o Layer of non pigmented epithelium.
o Internal limiting membrane.

20.  Supraciliary lamina –
 outermost condensed part of the stroma consist of pigmented
collagen fibres.
 Anteriorly become continues with the anterior limiting
membrane of iris.
 posteriorly, it is the continuation of the suprachoroidal lamina.
 Stroma—
 Consist of connective tissue of collagen and fibroblast.
 Ciliary muscle, vessels, nerves and cells are embedded in
stroma.
 Layer of pigmented epithelium-
 Forward continuation of the retinal pigmented epithelium.
 Anteriorly become continues with the anterior pigmented
epithelium of iris.

21.  Layer of non pigmented epithelium-
 Forward continuation of sensory retina.
 Continues anteriorly with the posteriorly pigmented
epithelium of iris.
 Internal limiting membrane-
 Forward continuation of the internal limiting membrane of
the retina.
 Lines the non-pigmented epithelial layer.

22. CILIARY PROCESS
🞭 Finger like projection from the pars plicata part of the
ciliary body.
🞭 They are white in color
🞭 Process is lined by two layer of epithelial cell .
🞭 It contain blood vessels and loose connective tissue
🞭 these process are the site of aqueous production.
🞭 Each process is about 2 mm long and 0.5 mm in
diameter.
🞭 They are about 70 to 80 in numbers.

24. CILIARY MUSCLE
 Occupies most of the outer part of the ciliary body.
 These are non striated muscle having three parts
1. Meridional fibers- Help in aqueous outflow.
2. Circular fibers
3. Oblique fibers
- Help in accommodation.
- Help in Aqueous outflow.
 Ciliary muscle is supplied by parasympathetic fibers
through the short ciliary nerves.
Action- Main action is to slacken the suspensory
ligament of the lens and thus help in
accommodation.

29. EMBRYOLOGY
 Mainly derived from the inner vascular layer
of the mesenchyme that surrounds the optic
cup
 Melanocytes of choroid originate from the
neural crest.

30. MICROSCOPIC STRUCTURE OF
CHOROID
 Choroid consist of four layers.
 Suprachoroidal lamina.
 Stroma.
 Choriocapillaris.
 Bruch's membrane.

32. 1.Suprachoroid lamina (lamina fusca):
Thin membrane of condensed collagen fibers,
melanocytes and fibroblast.
It consist of potential space between sclera and choroid
known as supra choroidal space.
 The potential space contains the long posterior ciliary arteries
and nerves.
2. Choroidal stroma:
Consist of loose collagenous tissue with some elastic and
reticular fibers.
 Contain pigmented cells and plasma cells.
 It forms the main bulk of the choroid.
It consist of two types of vessels Medium vessels and large
vessels

33.  3. Layer of Choriocapillaris
 It nourishes the pigmented epithelium and outer layer of sensory
retina.
 Choriocapillaries contain a basement membrane.
 Receive blood from medium and large vessels of stroma.
 The capillary walls are fenestrated and contains pericytes
4. Bruch's membrane:
 innermost layer of choroid having thickness 2-4 mm.
 Multilayered structure lies between the choriocapillaris and
pigmented epithelium of retina.
 It consist of five layers:-
• Basement membraneof retinal pigmentedepithelium
• Inner collagenfibers
• Middleelasticfibers
• Outer collagenfibers

36. BLOOD SUPPLY OF UVEAL TRACT
🞭 The uveal tract is supplied by three sets of artery.
 Short posterior ciliary artery- Arises as two trunks from the
ophthalmic artery .
 It pierce the sclera around the optic nerve and supply the
choroid in a segmental manner.
 Long posterior ciliary artery-- two in number nasal and temporal
.
 Pierce the sclera obliquely on medial and lateral side of the
optic nerve and supply the ciliary body.
 Anterior ciliary artery– Derived from muscular branches of
ophthalmic artery.
 7 in numbers– 2 each of superior, medial, inferior rectus
muscle and one from lateral rectus muscle
 these artery gives branches to sclera , limbus and conjunctiva.

38. NERVE SUPPLY
 The iris receives its sensory and autonomic
nerve supply from the long and short ciliary
nerves.
 The long ciliary nerves are branches of the
nasociliary branch of the ophthalmic division
of the trigeminal nerve. These fibers
innervate the dilator pupillae.
 • The short ciliary nerves arise from the
ciliary ganglion and contain postganglionic
parasympathetic nerve fibers.
 The parasympathetic innervates the
sphincter pupillae.

39.  The choroid is innervated by the long and
short ciliary nerves.
 The long ciliary nerves are branches of the
nasociliary nerves, a branch of the
ophthalmic division of the trigeminal nerve.
(sensory & parasympathetic) –
 The short ciliary nerves arise from the ciliary
ganglion and carry parasympathetic fibers
and sympathetic fibers.
 The ciliary muscle is innervated by the
postganglionic parasympathetic fibers
derived from the oculomotor nerve; The nerve
fibers reach the muscle via the short ciliary
nerves.

41. UVEITIS
 Also known as Iridocyclitis.
 Inflammation of uveal tissue.
 Common cause of blindness.
 Associated with systematic autoimmune disease.
 Symptoms and signs
 Ciliary flush
 Burning of the eye
 Redness of the eye
 Blurred vision
Photophobia or sensitivity to
Light.
 Irregular pupil.

42. ENDOPHTHALMITIS
 It is an inflammation of the internal coats of the eyeball
 It is a possible complication of all intraocular surgeries,
particularly cataract surgery, with possible loss of vision and the eye
itself.
 CAUSES-
 Bacterial and fungal infection
 penetrating trauma
 allergic reaction
 Symptoms-
 severe pain
 loss of vision
 redness of the conjunctiva
 Photophobia
 Management-
 Topical therapy
 Subconjunctival infections
 Intravitreal injection.

43. PANOPHTHALMITIS
 Inflammation of the whole eyeball including tenon’s
capsule.
 Eyeball is filled with pus
 Uveal tract is infiltrated with inflammatory cells like WBC.
 Symptoms-
 Ocular pain
 Headache
 Complete loss of vision
 Swelling of eyes.
 Management-
 anti-inflammatory and analgesics should be started
immediately.
 use broad spectrum of antibodies to prevent further
spread of infection.