Dr. Mujahid Khan

Ophthalmic Artery:
• It is a branch of Internal Carotid Artery
• Emerges from cavernous sinus
• Runs forward lateral to the optic nerve
• Reaches the medial wall of the orbit
• Gives away several branches

• Is a small branch
• Pierces the meningeal sheath of optic nerve & gain entrance to the nerve
• Enters the eyeball at the centre of optic disc
• Divides into 2 branches called end arteries

• Can be divided in two groups
• Anterior group enters the eyeball near the corneoscleral junction
• Posterior group enters the eyeball near the optic nerve

• It supplies the lacrimal gland

• Are distributed to the skin of the forehead

• Superior ophtalmic vein communicates in front with the facial vein
• Inferior ophthalmic vein communicates with the pterygoid plexus through the inferior orbital fissure
• Both the veins pass backward through superior orbital fissure & drain into cavernous sinus

• No lymph nodes or vessels are present in the orbital cavity

• Eyeball consists of 3 coats:
• The fibrous coat
• The vascular pigmented coat
• The nervous coat

• Made up of posterior opaque part, the sclera & anterior tranparent part cornea

• Composed of dense fibrous tissue
• Pierced by optic nerve posteriorly and is fused with the dural sheath of the nerve
• Lamina Cribrosa is the area of sclera that is pierced by optic nerve fibers
• Also pierced by ciliary arteries & nerves
• Is continuous in front with the cornea

• Is transparent
• Responsible for refraction of light entering the eye
• It is in contact with the aqueous humor posteriorly

• Consists from behind forward:
• Choroid
• Ciliary body
• Iris

• Is composed of an outer pigmented layer and an inner highly vascular layer

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• Is continuous posteriorly with choroid
Anteriorly lies behind the peripheral margin of iris
• Composed of:
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• Ciliary ring
Ciliary process
Ciliary muscle

• Ciliary ring is the posterior part of the body, has shallow grooves, Ciliary striae
• Ciliary processes are radially arranged folds connects the suspensory ligaments of the lens
• Ciliary muscle is composed of meridianal and circular fibers of smooth muscles

• Is a thin, contractile, pigmented diaphragm
• Has central aperture called pupil
• Is suspended in the aqueous humor between the cornea and lens
• Its periphery is attached to the anterior surface of the ciliary body
• Divides the space between cornea and lens into anterior & posterior chambers

• Consists of an outer pigmented layer & inner nervous layer
• Its outer surface is in contact with choroid
• Inner layer in contact with the vitreous body
• Posterior three-fourths is the receptor organ
• Macula lutea is the oval yellowish area in the center of the posterior part
• Fovea centralis is the central depression

• Optic nerve leaves the retina to medial side of macula lutea by the optic disc
• Optic disc is depressed at its center, where it is pierced by central artery
• Optic disc is insensitive to light and referred as blind spot
• Optic disc is seen to be pale pink with ophthalmoscope examination

• Enters the orbit from middle cranial fossa by passing through the optic canal
• Accompanied by ophthalmic artery
• It is surrounded by sheaths of pia, arachnoid and dura maters
• It runs forward and laterally within the cone of the recti muscles

• Pierces the sclera at a point medial to the posterior pole
• The meninges fuse with the sclera
• The subarachnoid space extends forward as far as the eyeball
• A rise in pressure of the CSF within the cranial cavity is transmitted to the back of the eyeball

• Arises from the ophthalmic division of the trigeminal nerve in the lateral wall of the cavernous sinus
• Enters the orbit through the lower part of the superior orbital fissure
• Crosses above the optic nerve with the ophthalmic artery
• Ends by dividing into the anterior ethmoidal and infratrochlear nerves

• Communicating branch to the ciliary ganglion
• The long ciliary nerves (2-3 in number)
• Posterior ethmoidal nerve
• Infratrochlear nerve
• Anterior ethmoidal nerve
• External nasal nerve

• It is about the size of a pinhead
• It is a parasympathetic ganglion
• Situated in the posterior part of the orbit on the lateral side of the optic nerve
• Receives its preganglionic parasympathetic fibers from the oculomotor nerve via nerve to inferior oblique
• The postganglionic fibers leave the ganglion in the short ciliary nerves

• Aqueous Humor
• Vitreous body
• lens

• Clear fluid fills the ant. & post. Chambers
• Is a secretion from ciliary processes
• Drained away through canal of Shlemm
• Obstruction to its draining results in glaucoma
• Glaucoma causes degenerative changes in the retina

• Supports the wall of the eyeball
• Maintains its optical shape
• Nourishes the cornea and lens
• Removes the products of metabolism

• Is a tranparent gel
• Fills the eyeball behind the lens
• Hyaloid canal is a narrow channel runs through it extends from optic disc to posterior surface of the lens
• Canal is filled with hyaloid artery in fetus
• Contribute in the magnifying power of eye
• Supports posterior surface of lens

• Is a transparent, biconvex structure
• Enclosed in a transparent capsule
• Situated behind the iris & in front of vitreous
• Encircled by ciliary process
• Assumes globular shape due to tense elastic capsule
• Its circumference attached to the ciliary process by suspensory ligament

• Suspensory ligament keeps the elastic lens flattened
• Ciliary muscle contracts to accommodate the eye for close objects
• Lens becomes dense & less elastic in advance age resulting in presbyopia
• Glasses are used to overcome presbyopia