Iris

Ciliary Body

Choroid

Cornea to Equatorial Lens. 

Inclusive of both Anterior and Posterior chambers.

1. Anterior Border Layer

2. Iris Stroma

3. Anterior Iris Epithelium

4. Posterior Iris Epithelium

Pigmented and non-pigmented cells

Collagen fibrils

Ground substance

Action of making pupil smaller.

Contraction of the sphincter muscle. 

Relaxed dilator muscle.

"Miotic Pupil"

Action of pupil dilation.

Relaxation of sphincter muscle.

Contraction of dilator muscle.

"Mydriatic Pupil"

Fibers arranged radially. 

Contraction pulls iris toward the root.

Myoepithelial derived from neural ectoderm

Pigmented

Basal portion composes the dilator muscle

Heavily pigmented

Simple Columnar Epithelium

A. Anterior Border Layer

B. Pigment Ruff (Pupillary Margin)

C. Sphincter Muscle

D. Arcades of Minor Arterial Circle

F. Dilator Muscle

G. Anterior Epithelium

H. Posterior Epithelium

A. Pupillary Portion

B. Ciliary Portion

C. Fuch's Crypts

D. Pupillary Ruff

E. Major Arterial Circle

F. Minor Arterial Circle

G. Sphincter Muscle (Circular)

H. Dilator Muscle (Radial)

I. Radial (Longitudinal) Contraction Furrows

Ciliary Processes

Wider, anterior portion

Flat Body

Extends posteriorly from pars plicata

Fibrous attachments to lens

Tension on zonules varies with contraction state of the ciliary muscle.

Contraction of muscle = Decreased zonule tension

Relaxation of muscle = Increased zonule tension

[Outer - Inner]

1. Supraciliaris

2. Ciliary Muscle

3. Ciliary Stroma

4. Ciliary Epithelium

Outermost layer of ciliary body

Loose CT in ribbonlike layers

Allows the ciliary body to slide against sclera without damaging the tissue

Smooth Muscle fibers 

Arranged: radially, longitudinally, circularly

Adjacent to Supraciliaris

Parallel to sclera

Bundles resemble a narrow V (base at scleral spur, apex at choroid)

Inner to the fibers of Brucke

Wider, shorter 

Transition from logitudinal fibers to circular fibers

Innermost region of Ciliary Muscle

Sphincter type of action

Near major arterial circle

1. Longitudinal Fibers

2. Radial Fibers

3. Circular Fibers

D. Scleral Spur

Loose CT

Between Ciliary Muscle and Epithelial Layers

Highly Vascular--contributes to ability to make aqueous

Forms core of ciliary processes

Outer-Pigmented Layer

Inner Non-pigmented Layer--responsible for secretion of aqueous humor components

Blood-Aqueous Barrier

Aqueous produced by active secretion and microfiltration (aka ultrafiltration)

Depends on Na+/K+ ATPase pump

Carbonic Anhydrase catalyzes the production of HCO3- 

Secretion can be slowed by inhibiting enzyme

Gives rise to:

Anterior Iris Epi

Outer, pigmented ciliary epi

Retinal pigmented epi (RPE)

Gives rise to:

Posterior Iris Epi

Inner, non-pigmented ciliary epi

Neural retina

Ora Serrata to Optic nerve

Sandwiched between reina and sclera

Provides nutrition to outer 1/2 of retina

Outer --> Inner

1. Suprachoroidal Lamina ("Lamina Fusca")

2. Choroidal Stroma

3. Choriocapillaris

4. Bruch's Membrane ("Basal Lamina")

CT joining Sclera to Choroid

Pigmented

Suprachoroidal space carriees long posterior arteries and nerves to anterior of globe

Pigmented, vascularized, loose CT

Vessels arise from short posterior ciliary arteries

Haller's & Sattler's Layers

Sole blood supply to macular region of retina

Outer --> Inner

1. Basement membrane of choriocapillaris

2. Outer collagenous zone

3. Elastic layer

4. Inner collagenous zone

5. Basement membrane of retinal pigment epithelium

Selective control of release into posterior chamber

Tight junctions usually prevent passage of large molecules

Non-fenestrated blood vessels of the iris and zonula occludnds junctions of the endothelial cells also contribute

Enter globe around optic nerve

Branches form the choroidal circulation

Travel through suprachoroidal space

Join anterior arteries to form Major Circle of iris

Nasociliary branch of Trigeminal Nerve (CN V)

Pain with movement of inflamed tissues

Go to ciliary muscle and choroidal vessels

Sympathetic from cervical ganglion also go to iris dilator.

Parasympathetic from ciliary ganglion also go to iris sphincter.

Pigment Loss

Dilator atrophy

Sphincter muscle sclerosis: challenge to dilate

CT increases

Accommodation decreases: Presbyopia

Decrease in choroidal blood flow

Bruchs membrane:

Thickens

Deposition of basement membrane in collagenous zones

"Drusen" - Macular Degeneration precursor, yellow-white deposits in inner collagenous zone

Movement of nutrients and waste pdt is hampered