Lecture 1 - Orbit to TED Flashcards
(170 cards)
1
Q
First step of embryogenesis, multiplying (mitosis)
A
Proliferation
2
Q
Second step of embryogenesis- movement and changes in shape of cells
A
Motility
3
Q
Third step of embryogenesis- role assignment of cells
A
Determination
4
Q
Fourth step of embryogenesis- some genes will be expressed in only certain parts of the body
A
Differentiation
5
Q
part of the 3 layered gastrula that becomes the mouth
A
Blastopore
6
Q
part of the 3 layered gastrula that becomes the digestive tube
A
archenteron
7
Q
Fertilized egg- 2 cell- 4 cell- 8- cell- 16 cell - WHAT?- blastula- 2 layered gastrula- 3 layered gastrula
A
Morula
8
Q
Lung, Thyroid, Digestive/ Pancreatic cells are formed by which embryonic layer?
A
Endoderm (internal layer)
9
Q
Cardiac, skeletal, and smooth muscle cells, Tubule cells of kidney, and RBC’s are formed by which embryonic layer?
A
Mesoderm (middle layer)
10
Q
Skin and pigment cells and Brain Neurons are formed by which embryonic layer?
A
Ectoderm (external layer)
11
Q
ocular component developed at 2.5 mm stage
A
optic pit depressions
12
Q
ocular components developed at 4 mm stage
A
optic stalk, vesicle, lens plate
13
Q
ocular component developed at 5 mm stage
A
optic cup by invagination
14
Q
ocular component developed at 9 mm stage
A
Lens vesicle - separated from surface ectoderm
15
Q
ocular components developed at 13 mm stage
A
choroidal fissures close, posterior lens grows forward
16
Q
ocular components developed at 65 mm stage, after 3 months
A
all basic components of eye are now present
17
Q
ocular muscles derived from the Neuroectoderm
A
Iris sphincter and dilator
18
Q
ocular tissues derived from neuroectoderm
A
RPE, PCE, NPCE, pigmented iris epithelium,
19
Q
lens, conjunctive, and gland tissue are derivatives of which embryonic tissue
A
Surface Ectoderm
20
Q
ocular blood vessels, EOMs, temporal sclera are derivatives of which embryonic tissue?
A
Mesoderm
21
Q
Embryonic tissues that derive the vitreous
A
Mesoderm, Surface Ectoderm, Neuroectoderm
22
Q
Age of gestation when orbital bones fuse and ossify
A
6-7 months
23
Q
angle between orbits in stages of early development
A
180 degrees
24
Q
angle between orbits at time of birth
A
70 degrees
25
angle between orbits at adulthood
68 degrees
26
At what age does the orbit reach adult size
16 years old
27
Approximate volume of the adult orbit
30 ml
28
Effect of a maxillary sinus carcinoma on the orbit
roof of maxillary sinus is orbital floor, a carcinoma can invade upward and displace the orbit upward
29
infections of these sinuses can erode the lamina papyracea and involve the orbit.
ethmoid and sphenoid sinuses
30
infection of this sinus is often the cause of orbital cellulitis
Ethmoid sinus
31
defects in this orbital wall such as neurofibromatosis may result in visible globe pulsations transmitted from cerebrospinal fluid from brain
Defects in Orbital Roof
32
Structures passing through superior orbital fissure ABOVE the annulus of zinn
Lacrimal Nerve, Frontal Nerve, Trochlear Nerve, Superior Ophthalmic Artery
33
Structures passing through superior orbital fissure that pass THROUGH the annulus of zinn
Sup Division of Oculomotor Nerve, Nasociliary Nerve, Inferior Division of Oculomotor Nerve, Abducent Nerve
34
Structure passing through inferior orbital fissure
Inferior Ophthalmic Vein
35
Structures passing through Optic Canal and through annulus of zinn
Optic Nerve and Ophthalmic Artery
36
Internal carotid artery branches into the ophthalmic artery, that has more branches to supply blood to superficial face areas and the orbit. What are the branches of the Ophthalmic artery?
1. Central Retinal Artery, 2. Lacrimal Artery, 3. Short Posterior Ciliary Artery, 4. Long Posterior Ciliary Artery, 5. Ethmoidal Artery, 6. Supraorbital Artery, 7. Muscular Artery
37
Short posterior ciliary arteries branching from the ophthalmic artery form what structure in the optic nerve head?
Circle of Zinn
38
Long posterior ciliary arteries supply blood to what structure?
Choroid
39
two places that blood in the orbit drains into through veins
Cavernous sinus and pterygoid venous plexus
40
3 most common investigative testing scan types for ocular conditions
CT scans, MRI, Ultrasound
41
How does air appear on an x ray?
black
42
How does fat appear on an x ray?
dark gray
43
How does soft tissue and water appear on an x ray?
lighter shades of gray
44
How does bone and metal appear on an x ray?
white - more density = more white
45
CT scans of the orbit are typically done at 3 mm on which planes?
Axial - top/botton and Coronal - back/front
46
Disadvantages of CT scans
lack of tissue specificity (cannot distinguish diferent soft tissue masses) and potiential radiation effects
47
CT scan would be ordered when these 3 types of conditions are suspected
neoplasms, inflammatory masses, EOM hypertrophy - Graves
48
Scan that uses radiofrequency pulses to change movement of protons within of the nucleus of hydrogen atoms, releasing energy when returning to normal equilibrium
MRI - magnetic resonance imaging
49
unit of measurement to quantify the strength of the magnetic field in MRI
Tesla (T)
50
Tesla scale for MRI that provides the best anatomic details of the orbit, air/bone/fluid are hypointense (dark), fat is hyperintense so it is suppressed to eliminate the signal and achieve a better orbital view
T1 -weighted images
51
Tesla scale for MRI that is useful in revealing pathologic conditions (ischemia, inflammation, neoplasms) but not good for anatomic detail. Fluid is hyperintense, used with FLAIR (fluid attenuated inversion recovery) keeps the CSF dark, good for seeing white matter diseases due to periventricular changes
T2-weighted images
52
Form of MRI based on measuring the random motion of water molecules in a tissue, good for strokes and infarcs as it makes them look hyperintense.
Detects ischemia within minutes
Can estimate time of stroke
Diffusion Weighted Images
53
Form of MRI that shows areas of contrast- enchancement from a disturbance of the BBB
IV Gadolinium
54
When is a MRI contraindicated?
anything metal in body, pacemaker, life support, obese, claustrophobic
55
Type of scan where high frequency sound waves are emitted toward the tissue, the sound waves bounce back and are collected by receiver
Ultrasound
56
Type of ultrasound that can quantify the size and growth of a tumor and used to determine the axial length of the eye to determine the power of IOL implant after cataract surgery
A scan Ultrasound
57
Type of ultrasound that is the summation of multiple scans to give a 2D image
B scan Ultrasound
58
For an A scan ultrasound, every 1 mm error, typically caused by corneal compression (shorter than actual length) yields how much refractive surprise?
~3D refractive surprise, if compressed cornea and artificially short axial length, surprise will be too positive, causing a myopic surprise of 3 D for every 1mm too short
59
type of scan used to define the extent of an orbital venous disease, contrast injection can reveal presence of varices (dilated vessels)
Venography
60
type of scan required for detection of aneurysms less than 2 to 3 mm
Angiography
61
scan of choice for evluation of cerbrovascular veno-occlusive diseases such as dural venous or cavernous sinus thrombosis
Magnetic Resonance Venography - MRV
62
Invasive procedure to obtain cytology specimens from a lesion, performed with a CT scan for guidance, can be inconclusive, and risk for hemmorrhave, ocular penetration, tumor seeding along needle tracks
Fine - Needle Aspiration
63
Soft tissue involvement, proptosis, enopthalmos, dystopia, opthalmoplegia, changes in fundus can all indicate what kind of problems?
Orbital Problems
64
Which broad clinical sign of an orbit problem most often occurs in the form of lid and periorbital edema, ptosis, chemosis, and epibulbar injection?
Soft Tissue Involvement
65
3 Causes of soft tissue involvement that will cause orbital problems
thyroid eye disease- graves
orbital inflammatory diseases
obstruction to venous drainage - pseudotumor cerebri
66
Broad clinical sign of orbital problem assessed by estimating the amount of sclera visible above and below the limbus
Proptosis
67
what is assessed by only measuring the among of visible sclera above the limbus?
Lid Retraction
68
instrument that measures distance between front of cornea and orbital rim for each eye, normal is less than 20 mm depending on race and sex, and no more than 2mm should be seen between each eye.
Exophthalmometer - (left eye reads 18 and right reads 21, right eye has proptosis)
69
term for proptosis with lid lag
exophthalmos
70
Is exophthalmos congenital, acquired, or both?
both
71
is exophthalmos unilateral or bilateral?
can be either unilateral or bilateral
72
exophthalmos should be considered when exophthalmometry reads what?
greater than 21 mm (bilateral) OR more than 3 mm difference between both eyes (unilateral)
73
if a patient has exophthalmos, should you be able to reposition the globe by pushing in? (retropulsion)
No, if exophthalmos, there will be resistance
74
most common cause of unilateral exophthalmos in children
orbital cellulitis
75
what things need to be ruled out when searching for the cause of exophthalmos? (7)
Graves, space occupying lesions, orbital cellulitis, leukemia, pseudotumor, glaucoma, high myopia
76
What needs to be ruled out when patient has Enophthalmos (retracted globe)
contralateral size-reduction disorders
77
when is a condition considered proptosis vs exophthalmos, besides lid lag?
exophthalmos is secondary to an endocrine condition while proptosis is secondary to a non-endocrine condition
78
What is the Kanski method for observing asymmetrical proptosis?
Patient is looking down and you look from above and behind, or opposite: patient looks up and you look from below and in front of the patient
79
Increase in ORBITAL CONTENT behind or beside the eyeball or EXPANSIVE LESIONS (benign or malignant, arising from bone, muscle, nerve, vessels, or connective tissue) are the two causes of what condition?
causes of Proptosis
80
What subtype of proptosis is characterized by expansion within the muscle cone, displacing the eye straight ahead?
Axial proptosis - remember that inferior oblique is not considered part of the muscle cone
81
What subtype of proptosis is characterized by a mass outside of the muscle cone, that also causes sideways or vertical displacement of the globe
Non-Axial Proptosis
82
What subtype of proptosis is characterized by a pulsation of an orbital malformation or transmission of cerebral pulsations in the absence of a superior orbital roof
Pulsating Proptosis
83
What subtype of proptosis is characterized by changes of the Valsalva Maneuver (internal compression) and a sign of orbital varices or meningocele- protrusion of meninges (spina bifida)
Positional Proptosis
84
What subtype of proptosis may result from sinus meningocele - protrusion of meninges into a sinus cavity
Intermittent Proptosis
85
Symptoms of proptosis in relation to EOM movements
Dissociation causing extension to be asymmetrical between eyes, and cause Diplopia
86
Possible situations of proptosis that cause pain as a symptom
rapid expansion, inflammation, infiltration
87
How can proptosis cause pupillary reflexes or color vision as symptons, physiologically
ON nerve compression/involvement BEFORE dramatic Visual Acuity Loss (VAL)
88
When does proptosis cause Visual Acuity Loss as a symptom?
not UNTIL the lesion affects the optic nerve or if arises from the optic nerve
89
Syndrome occurring when the superior orbital fissure is involved in trauma or contains a tumor, diplopia occurring due to cranial nerve 3, 4, 6 involvement, and anesthesia of cornea and fascial anesthesia caused by Nasolacrimal nerve (V1) involvement
Orbital Fissure Syndrome
90
Syndrome occurring when an expanding lesion at the apex of the orbit, can cause axial or non axial proptosis and optic nerve compression, sometimes causes diplopia, facial and corneal anesthesia
Orbital Apex Syndrome
91
in Orbital Apex Syndrome, what does it mean if the eye is turned down and out when the lid is retracted and has complete ophthalmoplegia?
complete CN3 Palsy
92
In Orbital Apex Syndrome, what does it mean if there is pupil involvement?
Aneurysm of posterior cerebral artery
93
an Axial Direction for Proptosis is an indication of what? (2)
cavernous hemangiomas (benign blood vessel tumor), optic nerve tumors
94
an Eccentric, non axial Direction for proptosis is an indication of what?
extraconal lesions
95
Mild grading with Hertel exophthalmometer
Mild - 21 to 23 mm
96
Moderate grading with Hertel exophthalmometer
Moderate - 24 to 27 mm
97
Severe grading with Hertel Exophthalmometer
Severe - 28 mm or more
98
Name for condition that can be present if proptosis is severe enough that the palpebral aperture (fissure) cannot be closed completely
Lagophthalmos - inability to close eyelids
99
backward displacement of the eye in the bony socket, due to loss of function of the orbitalis muscle, loss of supraduction is common, can be caused by blow out fracture to orbital floor
Enophthalmos- opposite of proptosis
100
How can Enopthalmos be caused by structural abnormalities
trauma like blowout fracture can cause eye to shift backward, or congenital abnormality
101
What are some causes of atrophy of orbital contents that lead to Enophthalmos
radiation, scleroderma, eye poking in blind infants (blind infants press on their own eyes)
102
what diseases can cause Sclerosing orbital lesions that result in Enophthalmos
Metastatic cirrhosis carcinoma and chronic inflammatory disease
103
Condition that gives the appearance of enophthamos (pseudo-enophthamos)
micropthalmos or phtisis bulbi (non functional, shrunken eye)
104
Displacement of the globe in the Coronal plane, vertical or horizontal, usualy due to an extraconal orbital mass- lacrimal gland mass, may co- exist with proptosis or enophthalmos, usually congenital
Dystopia
105
When is dystopia a major cause for concern?
if it is acquired and not congenital - indicates extraconal tumor or orbital fracture
106
Malposition of the ocular globe and orbit due to a mono or bilateral asymmetry and distortion of the bony structure
Orbital Dystopia
107
What can cause orbital dystopia in the form of downward displacement of the superior orbital margin and roof, or infero-laterally with associated nasoethmoidal injuries
Craniofacial Injury
108
Inability to move the eye, 1. due to a muscle restriction effecting EOMS (myopathic) or 2. affecting the nerve pathways of EOMs are affected due to poor innervation weak movement due to poor innervation, (Neurogenic), or 3. paralysis/weakness of one or more of the EOMs
Ophthalmoplegia
109
In myopathic Ophthalmoplegia, if the eye is turned Eso, which muscle is affected?
If the eye is turned inward, the MEDIAL RECTUS is affected, because it is turned inward due to muscle restriction, preventing the eye from turning back to center gaze- If Exo - Lateral Rectus etc.
110
An orbital mass would cause which type of ophthalmoplegia?
Myopathic ophthalmoplegia
111
A cranial mass would cause which type of ophthalmoplegia
Neuropathic ophthalmoplegia
112
Thyroid disease or orbital myositis causes which type of ophthalmoplegia?
Restrictive - Myopathic
113
Which nerve is associated with lesions in the cavernous sinus, posterior orbit (carotid cavernous fistula, Tolosa-Hunt syndrome and malignant lacrimal tumors) as cause for ophthalmoplegia
Oculomotor Nerve
114
Common injury that can restrain EOM's or fascia resulting in myopathic ophthalmoplegia, typically seen as the Eye looking Down because of Inferior Oblique Restriction
Blowout Fracture
115
What happens as a result of a meningioma making eye movements very painful?
Splinting - holding eyes still to prevent pain causes muscle rigidity. DeJesus discussed using a balloon to inflate lungs with a broken rib to prevent lung collapse from shallow breaths
116
If an eye cannot be moved (positive result) by the forced duction test, what kind of ophthalmoplegia does the patient have?
Myopathic ophthalmoplegia if cannot be moved
117
If an eye can be moved (negative result) by the forced duction test, what kind of ophthalmoplegia does the patient have?
Neurological ophthalmoplegia if eye can be moved
118
after performing Differential IOP test, if an increase in IOP of 8 mmHg is seen, what kind of ophthalmoplegia is suggested?
Myopathic ophthalmoplegia if >6 mmHg- not a safe bet
119
after performing Differential IOP test, if an increase in IOP of 4 mmHg is seen, what kind of ophthalmoplegia is suggested?
Neurological ophthalmoplegia, if
120
How does myopathic ophthalmoplegia effect saccades?
normal velocity with a sudden halt
121
How does neurological ophthalmoplegia effect saccades?
decreased velocity
122
Major fundus changes seen in patients with ophthalmoplegia (5) FACCS
Optic Disc Swelling, Optic Atrophy (palor-whitening), Cupping, Collaterals (optociliary shunt vessels), Choroidal folds
123
one of the fundus changes from ophthalmoplegia, anastomosis of vessels to reroute blood from an obstructed vein, typically caused by retinal vein occlusion, optic nerve glioma or sheath meningioma, or chronic papilledema
Collaterals - optociliary shunt vessels
124
One of the major fundus changes from ophthalmoplegia, can occur in cases of intraocular hypotony, retinal detachment, or orbital mass, not associated with severe VAL, typically caused by orbital tumors, dysthyroid opthalmopathy, mucoceles
Choroidal folds
125
RVO, optic nerve glioma or sheath meningioma, and chronic papilledema can cause what in the fundus?
Collaterals- optociliary shunt vessels- associated with ophthalmoplegic fundus changes
126
Hypotony, retinal detachment, orbital mass/tumor, dysthyroid ophthalmopathy, mucoceles and no severe VAL are signs of what in the fundus area?
Choroidal folds - associated with ophthalmoplegia
127
Proptosis in the absence of orbital disease, caused by high myopia, globe is not pushed forward, but gives the appearance due to a small vacity, enlarged globe, retracted lid, recessed globe or droopy lid of opposite eye- good case hx needed to provide clues for cause
Pseudoproptosis
128
How does irregular facial asymmetry give the appearance of proptosis (psuedoproptosis)
smaller cavity can cause the eye to look like it is protruding outward
129
If the globe is severely enlarged, it can appear to bulge outward like proptosis, but instead, it can be caused by?
High myopia (longer axial length), Buphothalmos (enlarged eye, can be caused by congenital glaucoma)
130
What condition is suggested by lid retraction (psuedoproptosis cause) when there is also upward movement of the eye?
Congestive dysthyroid disease
131
What condition is suggested by lid retraction (psuedoproptosis cause) when there is a deficiency in upward gaze?
weakness of superior rectus after an operation on a rectus muscle
132
What condition is suggested by lid retraction (pseudoproptosis cause) when there is excessive stimulation of levator muscles in Bells phenomenon (up and out when eye closed?
Seventh nerve palsy
133
Lid retraction causing pseudoproptosis with upward eye movement can be caused by what muscle receiving excessive stimuli from nerve fiber of superior rectus
Levator muscles
134
What syndrome causes lid retraction with upward movement as a cause of pseudoproptosis, and is caused by pretectal or periaqueductal lesion in midbrain
Dorsal Midbrain Syndrome
135
Lid retraction with downward eye movement caused tumor trauma, or stroke effect are caused by ?
aberrant regeneration to CNIII
136
syndrome involving the superior oblique tendon sheath that causes lid retraction with downward movement of the eye
brown syndrome
137
parkinsonian-like disease that causes lid retraction with downward movement of the eye
progressive supranuclear palsy
138
A patient with a scar on the eye lid could prevent the levator muscle from doing what?
relaxing when looking down, causing the upper lid to retract
139
lid lag during downward gaze ( graefe sign) is typical in what kind of exophthalmos?
noncongestive type of dysthyroid exophthalmos
140
retraction syndrome with underaction of lateral rectus muscle and spillover to levator causing widening
Duane syndrome (remember brown is retraction when looking down, this is retraction when the levator muscle is not working
141
History, External Examination, Ocular examination, vital signs with temp, orbital CT scan, MRI or ultrasound, lab tests, consider excision or biopsy
Work up for unknown etiology of proptosis
142
What lab results would be shown if hyperthyroidism is the cause of the proptosis?
T3, T4 elevation and TSH decrease
143
condition caused by excessive quantities of thyroid hormones due to overproduction, ectopic overproduction (paraneoplastic syndrome) loss of storage function - leak from gland, usually presents in 30 - 40 y/o women
Thyrotoxicosis
144
Most common causes of hyperthyroidism
Thyroid Eye disease or Graves
145
condition caused by IgG antibodies producing inflammation of the EOMs, inflammatory cells infiltrate vascularized fibro-fatty orbital tissue
Thyroid Eye Disease
146
If a 35 year old female smoker comes into your office with complaint of lid retraction, proptosis, taking radioactive iodine for thyroid tx, and showing signs of optic neuropathy and restrictive myopathy, what is the most likely diagnosis?
Thyroid Eye Disease
147
Thyroid eye disease often presents with systemic hyperthyroidism (rapid pulse, hot dry skin, goiter, weight loss ) and can also be present with what condition marked by muscle weakness in addition to double vision and ptosis, sometimes in patients with thymus tumors
Myasthenia Gravis
148
What disease is classified like this?
No signs or symptoms
Only signs - lid lag, lid retraction
```
Soft tissue involvement- kertoconjuctiv, perioribital swell
Proptosis
Extraocular involvment
Corneal ulceration
Sight loss
```
Dysthyroid Ophthalmoplegia
149
Lid presents with one of these four conditions could be a sign of what disease: mild left lid retraction, mild bilateral lid retraction w/o proptosis, severe bilateral lid retraction, right lid lag on down gaze
Thyroid Eye Disease
150
cause of lid retraction in TED in only the levator palpebrae
fibrotic contraction
151
cause of lid retraction in TED that happens in response to hypotropia produced by fibrosis and tethering of the inferior rectus
secondary overaction of levator-superior rectus complex
152
cause of lid retraction in TED that occurs as a result of sympathetic overstimulation secondary to high levels of thyroid hormones
Humorally-induced overaction of Muller muscle
153
name of the sign marked by lid retraction in primary gaze
Dalrymple's Sign
154
name of the sign marked by a staring, frightening, and scary look
Kocher Sign
155
name of the sign marked by lid lag on downward gaze
Von Graefe
156
how do we treat mild lid retraction?
May not need treatment because it can spontaneously improve
157
how do we treat lid retraction by decreasing vertical dimensions of the wide palpebral fissures, after the proptosis and strabismus have been addressed (lids treated last)
Surgery - last treatment because orbital decompression will affect the motility and eyelid positions
158
3 surgeries that can be done for lid retraction:
mullerectomy, lower lid retractor recession, botulin injection
159
30 - 40% of patients with TED develop ophthalmoplegia secondary to muscle fibrosis, what are the 4 most common ocular motility defects: EADA
Elevation- IR
ABduction-MR
Depression- SR
ADduction-LR
Fibrosis means the muscle loses contractility, so for example, eye cannot elevate because the IR is stiff and scarred, not restrictive but unable to lengthen
160
uncommon but serious complication of compression of the ON or blood supply to orbital apex by congested and enlarged recti, may lead to severe visual impairment
Optic neuropathy
161
If optic neuropathy does occur in response to thyroid eye disease causing congested muscles to compress the optic nerve, what signs might be noticed?
Central vision loss- reduced VA, positive APD, decreased CV, VF defect, increased IOP
162
What is the treatment for optic neuropathy in the case of thyroid eye disease?
intravenous methylprednisolone, orbital decompression if medication is ineffective or contraindicated
163
Clinical Pearl: why should you never assume that disproportionate vision loss is nothing more than a minor corneal complication?
You will miss optic neuropathy!
164
primary Differential diagnosis for Graves disease-TED
3rd nerve palsy with aberrant regeneration
165
```
How do you treat TED/ Graves?
1 keratitis
2 eyelid edema
3 proptosis and corneal ulcer
4 diplopia w/ inflammation
5 vision loss due to optic neuropathy
```
1 treat exposure keratitis with Refresh (eyes dont close)
2 Elevate head at night if pt has eyelid edema
3 prednisolone then orbital decompression
4 prednisolone, taper off quickly if no improvement, EOM sx may be needed
5 Predinosolone, radiation, orbit decompression
166
TED proptosis Management Considerations
1 congestive phase for progressive and painful proptosis
2 when steroids are not effective
3 combination therapy
4 when non invasive methods are ineffective, for cosmetics, or as primary tx
1 oral or intravenous prednisolone
2 radiation therapy
3 irradiation, azathiprine (immune suppression), prednisolone
4 surgical decompression
167
TED Follow up- how often should you see a patient with no exposure problems and mild to moderate proptosis
every 3-6 months
168
TED follow up- why should a patient with TED and fluctuating diplopia or ptosis be given the Tensilon test (edrophonium chloride)
to rule out myasthenia gravis
169
TED follow up- is optic nerve compression a serious condition?
REQUIRES IMMEDIATE ATTENTION
170
TED follow up- besides optic nerve compression, what possible symptoms require prompt attention?
advanced exposure keratopathy and severe proptosis
