ANATOMY & PHYSIOLOGY OF THE EYEBALL

Department of OphthalmologyBrawijaya University

2008

School Rules• Pay Attention• Be Silent

External landmark of the eye

Medial canthus

Limbus

Orbital section of lid

Lateral canthus

Tarsal section of lid

Internal part of the eye

The ConjunctivaTransparent mucous membrane :• Palpebral conjunctiva

Posterior surface of the eyelid• Bulbar conjunctiva

Allows eye movement• Fornices conjunctiva

Junction between palpebral conjunctiva and bulbar conjunctiva

The Conjunctiva

Bulbar conjunctiva

Fornices conjunctiva

Palpebral conjunctiva

The conjunctivaHistology :• Conjunctival epithelium :

– Surface epithelial : mucous secreting goblet cells proper dispersion precorneal tear film

– Basal epithelial • Conjunctival stroma :

– Adenoid layer : follicle-like structure– Fibrous layer : papillary reaction

The Conjunctiva

Papillary reaction

Follicular reaction

The conjunctiva• Blood supply :

– Artery : Anterior cilliary & palpebral– Anastomose with vein

• Nerve supply : – N. Trigeminus, ophthalmic division

• Lymphatics :– Join with eyelids lymphatics

The Sclera & Episclera• Sclera :

– collagen ↑↑• Episclera :

– Blood vessel ↑↑ to nourish sclera• Blood supply :

– Artery posterior cilliary (short & long)• Nerve supply :

– Cilliary nerve

The CorneaTransparent :• Uniform structure• Avascularity• Desturgence

The Cornea

The Cornea• Source nutrition for the cornea :

– Vessel of the limbus– Aqueus humor– Tears

• Sensory nerve :– N. Trigeminal, ophthalmic division

Uveal tract• Uvea : Iris, Cilliary body, Choroid• Iris :

– Control the amount of light entering the pupil• Cilliary body :

– Formation of the aqueus• Choroid :

– Between retina and sclera– Blood vessel ↑↑

Uveal Tract

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The Lens • Biconvex

• Avascular• Colorless• Transparent• Thick : 4 mm : 9 mm• Suspended by

zonula zinii

The Lens Lens has ability adjust its focus from

distance to near object because lens has ability to change shaped

Accomodation

The vitreous• Clear, avascular,gelatinous body• Vitreous contains water (99%), collagen,

hyaluronic acid• Vitreous base : straddles the ora serrata• Vitreous body : central & cortex vitreous • Outermost part of the vitreous (hyaloid) :

Vitreous cortex, divided into anterior cortex & posterior cortex

The vitreous

The Retina• Thin membranous structure that lines

the posterior aspect of the eye• Divided : central zone & peripheral

zone• Retinal base : anterior ora serrata posterior N. opticus• Retinal cells are stratisfied in 10 layers

The Retina

The Retina• Internal limiting membrane• Nerve fiber layer• Ganglion cell layer• Inner plexiform layer• Inner nuclear layer• Outer plexiform layer• Outer nuclear layer• Photoreceptor cell (rod &

cone)• Retinal pigment epithelium

(RPE)• Bruch membrane

Photoreceptors of the retina• ROD :

– Perifer >>– Scotopic vision

(vision in dim light

• CONE :– Central >>– Photopic vision

(vision in bright & color)

The Optic Nerve (N. II)• Part of anterior

visual pathway (optic nerve, optic chiasm, optic tract)

• Light retina optic nerve brain

RED EYE

Department of OphthalmologyBrawijaya University

2008

Various types of red eye• Conjunctival injection • dilatation of posterior conjunctival

vessel• Fornices limbus• Bright red• Epinephrine test ( + )

Various types of red eye• Perilimbal (circumcorneal) dilatation :

cilliary flush• Limbus fornix• Epinephrine test ( - )

Various types of red eyeEpiscleral injection Dilatation of episcleral

vessel Pink-purple

Various types of red eyeScleral injection dilatation of deeper episcleral

vessel Purple bluish discoloration

Various types of red eye• Subconjunctival bleeding rupture of the

vessel ( extravasation of the blood ) Bright homogenous localized red eye

Common causes of red eye• Mild irritation of the eye• Acute conjunctivitis• Acute anterior uveitis• Acute glaucoma• Corneal trauma or infection

Mild irritation of the eye

• Symptom :– Red eye– No pain– No visual

disturbance– No discharge

• Sign :– Conjunctival

injection diffiuse, more toward fornices

– Others : within normal limit

Acute Conjunctivitis• Symptom :

– Red eye– Foreign body

sensation– Itch– No visual

disturbance– Discharge :

moderate to copious

• Sign :– Conjunctival

injection diffiuse, more toward fornices

– Discharge– Papillary reaction– Follicular reaction– Cornea : clear

Acute Conjunctivitis

Acute Anterior Uveitis• Symptom :

– Red eye– Pain : moderate– Visual disturbance :

slightly blurred– No discharge

• Sign :– Conjunctival

injection diffuse, mainly circumcorneal

– Cornea : usually clear

– Pupil size : small

Acute Anterior Uveitis

Acute Glaucoma• Symptom :

– Red eye– Pain : severe– Nusea, vomiting– Visual disturbance :

markedly blurred– No discharge

• Sign :– Conjunctival injection

diffiuse– Cornea : Steamy– Pupil : moderately

dilated & fixed– Intra ocular pressure ↑

Acute Glaucoma

Corneal infection and Trauma• Symptom :

– Red eye– Pain : severe to

moderate– Discharge : watery or

purulent– Visual disturbance :

usually blurred

• Sign :– Conjunctival

injection diffuse– Cornea : change in

clarity related to cause

– Pupil : normal

Corneal infection

Corneal trauma