Explain what periorbital ecchymosis is and how it occurs?

Extravasation of blood into the periorbital skin.

The loose nature of subcutaneous tissue within the eyelids can cause accumulation of fluid.  If the soft tissues of the eye are crushed against the sharp bone, swelling and hemorrhage will occur in the eyelids. 

What sinuses are involved with a fracture of the medial wall of the orbit? 

What sinus may be involved in an inferior wall fracture of the orbit? 

what happens is the superior wall is penetrated? 

ethmoidal and sphenoidal sinuses

maxillary sinus 

it passes into the frontal lobe of the brain

Define exophthalmos.

Tumors of the _____ and _____ may erode the walls of the orbit and press on the optic nerve. 

The easiest entrance to the orbital cavity for a tumor in the brain is through the _______, however tumors can also gain entrance through the _______

Protrusion of the eyeball. 

ethmoid and sphenoid sinuses (middle cranial fossa tumor) 

superior orbital fissure

inferior orbital fissure  (temporal or infratemportal fossa tumore) 

The lateral side. 

The lateral wall is slightly shorter than the medial wall

Why does ptosis occur if the oculomotor n. is paralyzed? 

Damage of what nerve doesn't allow the eyelids to close fully? 

What response is lost when this nerve is destroyed? 

What also occurs? 

What does the above cause? 

CN III innervated the levator palpabrae superioris 

Facial N. (obicularis oris) 

Rapid protective blinking

Tonus is lost to the inferior eyelid and the lid falls away from the eye. 

Drying of the cornea, excessive lacrimation

What is a sty (hordeolum)? 

What causes it? 

Sty: a painful red suppurative swelling on the eyelid

Ciliary gland blockage

Cysts of the sebaceous gland are called what?

Obstruction of a tarsal gland produces inflammation and what? What does that cause?  

chalazia

tarsal chalazion

Pain as it protrudes near the eyeball and rubs against the eyelids

What is hyperemia of the conjunctiva? What causes it? 

What is the common name for conjunctivitis

Bloodshot eyes

Local irritation 

Pink eye. 

How do subconjunctival hemorrhages manifest? 

What nerves does the pupillary light reflex involve?

The sphincter pupillae m. is innervated by ______ fibers

When these fibers are interrupted what happens?  

bright or dark red patches deep to and within the bulbar conjunctiva 

CN II (afferent) and CN III (efferent) 

parasympathetic 

The pupil dilates due to uncontested action of sympathetic fibers to the dilator pupillae m. 

The retina and optic n. develop from the ____ ______. 

This is an outgrowth of the ___ ____ (embryonic forebrain) 

Explain the relationship between the optic n. and cranial meninges? 

The ______ artery and vein cross the subarachnoid space and run with the distal optic n. 

optic cup. 

optic vesicle 

Since the optic nerve is an extension of the brain, it takes the cranial meninges with it. The surround the nerve and the nerve is an extension of the subarachnoid space. 

Central artery and vein

The pigment cell layer of the retina develops from the _________ layer of the optic cup.  The neural layer develops from the ________ layer of the optic cup. 

outer

inner

Layers of the developing retina are separated in the embryo by the ______ ________.

What are the two parts of the retina? 

The pigment layer is firmly attached to the ______ but the _____ layer isn't. Thus the retina can easily detach 

intraretinal space

optic part (pigment and neural) and non-visual retina part

choroid

neural layer

A detached retina usually results from .....

What may a person with a detached retina complain of? 

A detached retina usually results from seepage of fluid between the neural and pigment cell layers of the retina. 

Flashes of light or specks floating in the eye. 

What causes edema of the retina? 

Define papilledema

What does it result from? 

Increased CSF pressure that slows venous return from the retina. 

Papilledema: swelling of the optic disc. Typically viewed during ophthalmoscopy 

Increased ICP and increased CSF pressure around optic n. 

Corneal abrasions and lacerations occur from...

As people age their lenses become _____ and ______. These changes reduce the ________ power of the lenses which causes a condition known as ________.  

Cloudiness in the lens is called ____. 

sharp objects, foreign objects, particles 

harder and more flattened.

Focusing

presbyopia 

cataracts. 

Blunt trauma to the eye can result in hemorrhage within the anterior chamber of the eyeball called _______.

When the eyeball has to be removed, where does an artificial eye sit? What allows some movement of the artificial eye? 

hyphemia or hyphema 

In the fascial sheath for the eye. 

The muscles of the eye remain attached to the muscle fascial sheaths which attach to the eye fascial sheath. 

If a patient has an absent corneal reflex, what nerve is affected? Why? 

What is the danger with a damaged sensory innervation to the cornea? 

CN V-1 and possibly CN VII (orbicularis oris) 

CN V-1 is responsible for sensory innervation to the cornea

The cornea is susceptible to injury by foreign particles

What muscles are affected by oculomotor n. palsy (CN III)?

What are the symptoms? 

ocular muscles, levator palpabrae superioris, sphincter pupillae

Eyelid droops & can't be raised, pupil fully dilated and non-reactive, pupil abducted and depressed

What is Horner's syndrome? 

What are the signs? 

Why does constriction of the pupil occur? 

A syndrome of interruption of the cervical sympathetic trunk. 

Pupillary constriction, eyelid drooping, absence of sweating on the face and neck, increased redness and temp of the skin

Parasympathetic stimulation of sphincter is unopposed. 

Explain glaucoma

What can result from glaucoma?

Pressure build-up of the anterior and posterior chambers of the eye due to a decrease in drainage of aqueous humor through the scleral venous sinus into the blood circulation

Blindness due to compression of the retina and retinal arteries.

Blockage of the central artery of the retina results in...

This usually occurs __________ and in _______ people

instant and total blindness

unilaterally

older

Occlusion of the central vein causes what? 

why? 

Slow, painless loss of vision

It may cause a block of one of the small retinal veins.