Blue boxes: Eye and Eye movements lecture

Question 1

Which two walls of the orbit are very weak?

Answer 1

The inferior and the medial walls of the orbit are weak

Question 2

Describe a blowout fracture to the orbit

Answer 2

Caused by an indirect trauma to the eye that displaces the orbital walls

Question 3

What could fractures of the medial wall of the orbit involve?

Answer 3

Ethmoidal and sphenoid sinuses

Question 4

What could fractures of the inferior wall of the orbit involve?

Answer 4

maxillary sinus

Question 5

Describe the superior wall of the orbit

Answer 5

It is stronger than the medial and inferior walls but it is translucent and can be penetrated easily; especially by sharp objects

Question 6

If you see protrusion of the eyeball, what should you be concerned about? (exophthalmos)

Answer 6

You should be concerned about intra-orbital bleeding which exerts pressure on the eye and pushes it out

Question 7

What is a concern of cancer in the sinuses?

Answer 7

Since it is so close to the optic nerve and the orbit, there is concern that it could mets or that it could compress the optic nerve

Question 8

How do tumors in the middle cranial fossa enter into the orbit?

Answer 8

Superior orbital fissure

Question 9

How do tumors that are in the temporal or the infratemporal fossa able to enter the orbit?

Answer 9

Through the inferior orbital fissure

Question 10

Why is the lateral side of the eyeball a good approach for orbital surgery?

Answer 10

The lateral side of the orbit does not extend as far anteriorly as the medial wall, so when the eye is turned in medially as far as possible, about 2.5 cm of the eyeball is exposed

Question 11

Differentiate between the sx that are seen in the eye when

1. There is a lesion in the oculomotor nerve
2. There is a lesion in the facial nerve

Answer 11

1. Paralysis of the elevator palpebral superioris and the superior eyelid droops
2. Paralysis of the orbiculares oculi preventing the eyelids from closing fully; no rapid protective blinking of the eye

Question 12

What are the various types of inflammation of the palpebral gland?

Answer 12

1. inflammation in the ducts of the ciliary gland: sty; painful and filled with pus
2. chalazia: cysts of the sebaceous glands
3. Tarsal chalazion: obstruction of the tarsal gland that protrudes toward the eyeball and rubs against the eyeball

Question 13

What is hyperemia of the conjunctiva? What causes it?

Answer 13

Redness of the eye that can be caused by irritation, or conjunctivitis

Question 14

What are subconjunctival hemorrhages?

Answer 14

Bright or dark patches deep to and within the bulbar conjunctiva that are the result of injury or inflammation

Question 15

Describe the development of the retina

Answer 15

1. From from the optic cup which is a neuroectoderm derivative
2. Optic vesicle carries the developing meninges with it; and the optic nerve is invested in the meninges and the central retinal artery is invested in the nerve
3. pigment cell layer of the retina from from the outside of the optic cup and the neural is from the inside of the optic cup

Question 16

Describe retinal detachment

Answer 16

Separation of the pigment cell later and the neural cell layer due to the seepage of fluid between the two layers

patient will complain of flashes of light or floating specks in the eye

Question 17

What are ways in which the retina can become detached?

Answer 17

Following a blow to the eye

Question 18

Describe the pupillary light reflex

Answer 18

Tested with a penlight testing the rapid constriction of the pupil which is testing CN II and CN III

Question 19

What is the first sign of compression of the oculomotor nerve?

Answer 19

Ipsilateral slowness of the pupil to contract

Question 20

Describe uveitis

Answer 20

Inflammation of the vascular layer of the eyeball that can cause visual impairment, and blindness

Question 21

When examining an eyeball with an ophthalmoscope, describe what you will see

Answer 21

retinal arteries are over the fundus from the optic disc

pale oval disc is on the medial side with the retinal vessels from the center

macula is on the posterior side of the eyeball and is darker than the retina because of the black melanin pigment that is made in the choroid

Question 22

Describe papilledema

Answer 22

an increase in CSF pressure that causes edema of the retina, which causes the optic disc to bulge, which can be seen in the fundoscopic exam

Question 23

Describe presbyopia

Answer 23

Blurriness and inability to focus due to the hardening and flattening of the lens

Question 24

What are cataracts

Answer 24

Cloudiness that is present on the eye secondary to a loss of transparency of the lens

Question 25

Describe coloboma of the iris

Answer 25

Secondary to the failure of the choroid fissure to close embryonically resulting in a keyhole pupil

Question 26

Describe glaucoma

Answer 26

Caused by a decrease in the outflow of the aqueous humor (through the canal of schlemm) that causes a pressure build up in the eye

blindness can result if left untreated for too long

Question 27

Describe an anterior hemorrhage of the eye

Answer 27

Caused by trauma to the eye or a blow to the eye, blood pools in the anterior chamber

Question 28

Describe an artificial eye

Answer 28

Artificial eye is inserted into the fascial sheath of the eye and the eye muscles will remain intact to the fascia, which means that there can still be minimal eye movements of the eye

Question 29

Describe a corneal reflex

Answer 29

edge of the cornea is touched with a piece of cotton; if a blink does not occur there could be a lesion in either CNv1 or CNVII

Question 30

Differentiate between a corneal abrasion and a corneal laceration

Answer 30

A corneal abrasion is typically caused by a particle that is present in the eye and a laceration is caused by a scratch to the eyeball

Question 31

What is Horner’s syndrome

Answer 31

Interruption of a cervical sympathetic trunk and there is no sympathetic stimulation of one side of the face; this results in constriction of the pupil, ptosis, anhydrosis, and redness of the skin from vessel dilation

Question 32

Describe oculomotor nerve palsy

Answer 32

Affects most of the eye muscles

superior eyelid droops and cannot be raised voluntarily (because of the obicularis oculi

pupil is fully dilated and abducted and depressed because of the lateral rectus and superior oblique (nothing is there to offset it)

Question 33

Describe abducent nerve palsy

Answer 33

Damage to the lateral rectus; individual cannot abduct the pupil; pupil is fully adducted and unopposed because of the medial rectus

Question 34

Describe blockage of the central retinal artery

Answer 34

Can cause total blindness; typically unilateral

Question 35

Describe blockage of the central retinal vein

Answer 35

The central retinal vein enters the cavernous sinus so thrombophlebitis of this sinus can cause a blockage of this vein which can result in slow painless loss of vision