Orbit and Eye Flashcards
1
Q
what happens to the orbit when there is blunt or penetrating trauma
A
blowout fracture- orbital floor and medial wall
2
Q
what are the symptoms of a blowout fracture
A
swelling, bruising, ocular trauma, diplopia, decreased movement of eye, enophthalmos, facial anesthesia (impingement of infraorbital nerve)
3
Q
what is the treatment for a blowout fracture
A
wait for swelling to subside, surgery for complex fractures, significant enophthalmos or entrapment of muscles
4
Q
what is the common tendinous ring made out of
A
thickening of periorbita
5
Q
which muscles do not originate in the annulus of zinn
A
obliques (superior and inferior) and levator palpebral superioris
6
Q
what is the primary and secondary action of the levator palpebral superioris
A
primary: elevation of upper eyelid (no secondary)
7
Q
what is the primary and secondary action of the superior rectus
A
primary: elevation, secondary: adduction and intorsion
8
Q
what is the primary and secondary action of the inferior rectus
A
primary: depression, secondary: adduction and extorsion
9
Q
what is the primary and secondary action of the medial rectus
A
primary: ADduction (no secondary)
10
Q
what is the primary and secondary action of the lateral rectus
A
primary: ABduction (no secondary)
11
Q
what is the primary and secondary action of the superior oblique
A
primary: depression and abduction, secondary: intorsion
12
Q
what is the primary and secondary action of the inferior oblique
A
primary: elevation and abduction, secondary: extorsion
13
Q
what direction are the axes of the eyes
A
anterior-posterior
14
Q
what direction are the axes of the orbits
A
lateral-medial
15
Q
what are the consequences of not having the axes of the eyes and orbits alined
A
actions of the superior and inferior recti and oblique muscles are complicated and to look straight ahead, the eyes must be slightly aDducted
16
Q
what do the superior rectus and superior oblique do together
A
intort
17
Q
what do the inferior rectus and inferior oblique do together
A
extort
18
Q
what do the inferior oblique and superior rectus do together
A
elevate
19
Q
what do the superior oblique and the inferior rectus do together
A
depress
20
Q
what do the lateral rectus, inferior and superior oblique do together
A
aBduct
21
Q
what do the medial rectus, inferior and superior rectus do together
A
aDduct
22
Q
how do you test the inferior oblique muscle on the H test
A
have the patient look UP
23
Q
how do you test the superior oblique muscle on the H test
A
have the patient look DOWN
24
Q
when do the superior and inferior oblique muscles raise and lower the eye
A
when the eye is aDducted or aBducted: the muscle axis is lined up with the eye axis
25
what is the special afferent innervation to the orbit/eye
CN 2 optic nerve
26
what is the general afferent innervation to the orbit
V1- ophthalmic division of trigeminal nerve (orbit, orbital contents and superior part of face) also suspends the ciliary gangion
27
what are 3 general efferent innervations to the orbit/eye
CN 3: oculomotor (GE to most of EOM and VE preganglionic parasympathetic to smooth muscles of eye), CN 4 and CN 6
28
what are the symptoms of a CN 6 lesion/palsy
(loss of lateral rectus) eye is turned medially and diplopia
29
what are the symptoms of a CN 4 lesion/palsy
(loss of superior oblique) affected eye is higher and deviated medially, very subtle, may also see head tilt away from affected side to counteract extorsion (from IO), diplopia
30
what are the symptoms of a CN 3 lesion/palsy
(oculomotor palsy) loss of all but lateral rectus and superior oblique muscles (also sphincter and ciliary), eye is directed down and out, ptosis, pupillary dilation and poor near focus
31
what is the blood supply to the orbit
branches of the ophthalmic artery (internal carotid): lacrimal, central retina, long/short posterior ciliary, supraorbital and supratrochlear, anterior and posterior ethmoidal and dorsal nasal
32
what is the venous drainage for the orbit
drain into the superior and inferior opthalmic veins which go to cavernous sinus (inferior ophthalmic vein may also drain into pterygoid venous plexus)
33
what is a cavernous sinus thrombosis
blood clot in cavernous sinus caused by a late complication of midface infection
34
what are the symptoms of a cavernous sinus thrombosis
headache, orbital content swelling, lateral gaze palsy, ocular motor palsy, ptosis, dilation, exophthalmos and visual impairment
35
what are the treatments for a cavernous sinus thrombosis
antibiotics, surgery to drain the sinus (morbidity is high and complete recovery is rare)
36
what is a carotid-cavernous sinus fistula
a rupture of internal carotid artery or its small dural branches in cavernous sinus caused by trauma or rupture of an aneurysm
37
what are the symptoms of a carotid-cavernous sinus fistula
trauma- marked swelling of orbital contents, pulsating exophthalmos, ocular motor palsy, vision impairment. Mild cases- diplopia and red, congested eye
38
what are the treatments for a carotid-cavernous sinus fistula
trans-venous endovascular surgery for serious cases, usually not life-threatening
39
what is the most common type of glaucoma
primary open angle glaucoma (OAG)- unknown cause
40
what are the symptoms of primary OAG
gradual loss of peripheral vision, "tunnel vision"
41
what are the treatments for primary OAG
usually a combination of drugs to lower IOP by increasing drainage or decreasing aqueous humor production
42
what is acute angle closure glaucoma
emergency- caused by iris bulging forward through the sudden dilation of pupils (darkness, stress, or medications)
43
what are the symptoms of acute angle closure glaucoma
severe, sudden eye pain, nausea and vomiting, halos, and blurred vision
44
what are the treatments for acute angle closure glaucoma
medications, iridotomy
45
what is secondary glaucoma
results in either primary open angle or acute angle-closure glaucoma, caused by eye injury, inflammation, tumor, diabetes, cataracts or steroids
46
what does the outer fibrous layer consist of
sclera and cornea
47
what does the middle layer (vascular/muscular) consist of
choroid: contains general afferents and vessels, ciliary body: smooth parasympathetic control, secretes aqueous humor, zonular fibers
48
what does the inner (visual) layer consist of
retina: optic part, optic disc and fovea centralis
49
what is the difference between a detached retina and a retinal tear
detached is an anterior displacement of vitreous that allows retina to pull away from choroid layer, tear is a hole in the retina and vitreous pools between it and choroid
50
what causes a detached retina
PVD (usually older patients), trauma, weak area in retina/thin, glaucoma, cataract surgery (most common in people over age 50)
51
what are the symptoms of a retinal detachment
flashes, sudden floaters, moving veil across vision
52
what are some treatments for a retinal tear or detachment
tear: photocoagulation, cryopexy (freezing) detachment: pneumatic retinopexy (air bubble or gas), scleral buckle or vitrectomy
53
what is another name for vortex veins
vorticose veins (4 large veins)
54
what causes papilledema
tumors, problems with CSF production/absorption, encephalitis, medications
55
what are symptoms of papilledema
headaches, blurry vision, diplopia
56
what are some treatments for papilledema
depends on the cause
57
what is the general afferent innervation to the cornea and sclera
ophthalmic nerve (V1)- nasociliary: long and short posterior ciliary branches
58
what is the visceral efferent to the smooth muscle of the eye (parasympathetics)
oculomotor nerve (CN3) parasympathetics - ciliary ganglion - short posterior ciliary nerves- to ciliary muscle and sphincter puillary muscle
59
what is the visceral efferent to the smooth muscle of the eye (sympathetics)
sympathetic plexus on internal carotid artery- through ciliary ganglion- long/short posterior ciliary nerves- dilator muscles
60
which structures out of: the cornea, lens, aqueous humor, and vitreous humor, bends light the strongest
the cornea and lens (but only the lens changes shape)
61
are the dilator pupillae fibers radial or circumferential
radial (sphincter pupillae are circumferential)
62
what is the afferent pupilary light reflex pathway
light hits retina --> CN 2 optic nerve carries signal to the brain
63
what is the efferent pathway for the pupilary light reflex
brainstem --> CN 3 oculomotor (inferior division) to parasympathetic root --> ciliary ganglion (synapse) then becomes the short posterior ciliary nerve which goes to sphincter pupilae muscle
64
what is the afferent pupilary dark reflex pathway
no light on retina --> CN 2 optic nerve --> brain
65
what is the efferent pupilary dark reflex pathway
brain --> spinal cord --> cervical sympathetic chain --> superior cervical ganglion (synapse) --> internal carotid plexus:
a) sympathetic root to ciliary ganglion (no synapse) to short posterior ciliary nerve to dilator pupilae muscle
b) V1 --> nasociliary nerve --> long ciliary nerve --> dilator pupilae muscle
66
what is the afferent pathway for the corneal touch reflex
short/long ciliary nerve --> ciliary ganglion (no synapse) --> nasociliary nerve --> V1 --> semilunar ganglion --> CN V --> brainstem
67
what is the efferent pathway for the corneal touch reflex
brainstem --> CN 7 --> temporal/zygomatic branches --> orbicularis occuli muscle
68
what happens if there are lesions on each CN 3, superior cervical ganglion or V1 of Trigeminal
dilated pupil/near focus problems = absence of pupil constriction, constricted pupil (miosis) = absence of pupil dilation, loss of corneal touch reflex
69
what is a stye (hordeolum)
acute, local inflammation from blockage of sebaceous and tarsal glands
70
what is a chalazion
chronic form of stye, can occur on skin, lid margin or tarsal side (more painful), usually bacterial
71
what are some treatments for a chalazion
warm compresses, antibiotics, steroids, incision and drainage
72
what is conjunctival hyperemia
(blood shot eyes) conjunctival blood vessels become engorged (local irritation)
73
what is conjunctivitis
"pink eye" infection of conjunctiva, usually bacterial or viral, can also be allergies
74
what are symptoms and treatment for conjunctivitis
redness, itchiness, discharge, treatment varies
75
what are the general afferents to the eyelid
V1 ophthalmic division of trigeminal nerve (lacrimal, supraorbital, supratrochlear, infratrochlear) and V2 infraorbital
76
what does a lesion of the general afferents to the eyelid cause
anesthesia of eyelid
77
what is the general efferent to the eyelid
CN 7 facial (temporal and zygomatic branches to orbicularis oculi)
78
what would a lesion to the general efferents of the eyelid cause
bells palsy or a cranial injury/cavernous sinus problem = complete upper eyelid ptosis
79
what is the visceral efferent to the eyelid
sympathetics to mullers muscle
80
what would a lesion to the visceral efferent of the eyelid cause
Horners syndrome
81
what is the general afferent to the lacrimal system
V1 ophthalmic division of Trigeminal nerve 5
82
what is the visceral efferent parasympathetic to the lacrimal system
secretomotor: preganglionics from CN 7 in greater petrosal nerve and nerve of the pterygoid canal to the pterygopalatine ganglion (synapse) --> postganglionics in zygomatic nerve and communicating branch to lacrimal gland
83
what is the visceral efferent sympathetic to the lacrimal system
inhibits secretion or change the viscosity of tears: preganglionics from T1-2 synapse in superior cervical ganglion --> postganglionics in internal carotid nerve and plexus to deep petrosal nerve and nerve of pterygoid canal to the pterygopalatine ganglion (no synapse) zygomatic nerve and communicating branch to lacrimal nerve
84
what is the blood supply to the lacrimal gland
ophthalmic artery branches
85
what is the venous drainage to the lacrimal gland
ophthalmic veins --> cavernous sinus
86
what are 3 types of tears
basal, reflex, and emotional
87
what are basal tears
lubrication, cleaning, removal of bacteria (normal parasympathetic stimulation)
88
what are reflex tears
from irritation, wash irritants from the cornea (afferent= trigeminal, efferent = facial)
89
what are emotional tears
from emotional stress, cause is unknown
90
what happens to tearing with a lesion in CN 5
reflex lacrimation is lost but emotional and basal lacrimation are retained
91
what happens to tearing with a CN 7 lesion- proximal to the geniculate ganglion
all lacrimation is lost, but tarsal, sebaceous and conjunctival glands can sometimes keep eye lubricated (i.e. basal tears)
