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67 Cards in this Set
- Front
- Back
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What is functional vision loss?
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subjective complaints that are contradicted by objective findings
-diagnosed by exclusion -adaptive mechanism to cope with stressful situations |
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What are malingerers
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people who feign illness usually for secondary gain such as emotional or financial reward
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What are some functional vision tests?
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1. patient observation
2. tangent screen visual fields at 1 m and then at 2 m with double the size 3. fog the good eye 4. stereo acuity tests 5. 4 diopter base out prism--recovery movement. 6. polaroid hectographed slide with polarizing glasses 7. plate 12 in ishihara |
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Macular disorders have what kind of color defect?
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blue/yellow
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optic nerve disorders have what kind of color defect?
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red/green
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If they have macular edema what test can you do to test it?
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photostress recovery time--30s
if they have macular edema, takes about 1 to 2 minutes to recover |
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What test can you do to test chiasmal lesion?
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red cap. desaturation in fields
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When do you have miosis?
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Aging
miotic drugs anterior uveitis Argyll Robertson pupil Horner's pupil |
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What is Argyll Robertson pupil?
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NEUROSYPHILIS
lesion in the region of Edinger Westhal nucleus you have a bilateral, miotic, irregular shaped pupil with POOR LIGHT response and GOOD NEAR response |
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What is Horner's pupil?
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loss of sympathetic tone
UNILATERAL miosi, and partial ptosis innervation to iris dilator and to Mueller's muscle in lids is interrupted aniso is worse in the dark heterochromia anhydrosis-loss of facial sweating |
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Why is there heterochromia in long standing Horner's?
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stromal melanin needs intact sympathetic so iris in affected eye is lighter in color
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Why is there mydriasis?
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1. mydriatic drug
2. trauma 3. Adie's pupil 4. oculomotor palsy III nerve 5. acute glaucoma |
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What is Adie's pupil?
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parasympathetic
lesion in ciliary ganglion affecting parasympathetic innervation aniso greater in light SLOW response to near, LAG in REDILATION ABSENT (weak) response to direct light VERMIFORM sectorial iris constriction reduced accommodation viral ciliary ganglion injury or idiopathic hypersensitivity to pilocarpine |
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Oculomotor palsy III nerve
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-ipsilateral ophthalmoplegia, ptosis
-3rd nerve passes lateral to posterior communicating artery and pupillary fibers lie on dorsomedial aspect of the nerve and can be compressed by aneurysm -posterior communicating artery aneurysm needs to be ruled out -vascular etiologies of 3rd nerve palsy with non-dilated pupil are HTN and diabetes where infarction of central nerve fibers results in EOM paralysis but spare pupil fibers |
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Acute glaucoma
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mid-dilated pupil from infarction involving iris sphincter, pain, redness, corneal edema, elevated IOP
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RAPD
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impairment of afferent pathway
lesion of optic nerve, chiasm, optic tract, or significant retinopathy -NO aniso |
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Where is the normal position of the upper lid?
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2mm below the limbus
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Where is the normal position of the lower lid?
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at the limbus
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What are some reasons for eyelid retraction?
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1. protrusion (bulging) of the globe (exophthalmos or proptosis)
2. retracted due to excessive sympathetic innervation to Muller's muscle 3. can be bilateral or unilateral 4.due to contralateral ptosis associated with Herring's law of excessive innervation required to lift ptotic lid transferred to opposite nonptotic lid |
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Grave's disease
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most common cause of lid retraction
clinical signs: lid retraction (Dalrymple's sign), proptosis (exophthalmos), lid and conjunctival edema, diplopia |
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What is an exophthalmometer?
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measures degree of proptosis or protrusion by noting the apex of cornea in front of the lateral orbital margin
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Asymmetry of how many mm is significant for proptosis?
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2mm
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Blepharoptosis
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ptosis. drooping of upper lid
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What are the lid retractors?
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CNIII, aponeurosis of the levator palpebral superioris and Mullers muscles
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What does the levator palpebral superioris divide into:
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Anterior portion: aponeurosis at the tarsal plate (innervated by CNIII)
Posterior portion: Muller's muscle (innervated by sympathetic system) |
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Myogenic ptosis
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muscle weakness, malfunction, mal-development or dystrophy of levator
*acquired |
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Congenital ptosis
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dygenesis-dystrophy of levator
poor elevation and depression ptotic lid higher on downgaze |
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most common cause of myogenic ptosis
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myasthenia gravis
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Myasthenia gravis
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abnormality in neuromuscular junction with abnormal AcH receptor sites. Associated with muscle weakness, difficulty swallowing, speaking, chewing, diplopia, ptosis
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What are some clinical observations of MG?
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1. lid twitch or flutter from down gaze to straight ahead
2. fatigue of lid in up gaze or repeated blinking 3. lid peek with prolonged closure resulting in incomplete lid closure (lagophthalmos) 4. rest or application of ice improved function with incre release of AcH |
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Aponeurotic ptosis
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involutional defect in levator aponeurosis or tendon insertion typically from AGING
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Clinical observations of aponeurotic ptosis
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1. stretching or disinsertion at or near superior border of tarsus
2. high or absent lid crease with thinning or attachment via skin aponeurosis 3. deep upper sulcus 4. ptosis worse on down gaze 5. over action of frontalis 6. diminished integrity of levator but function is still good 7. etiologies include aging trauma and contact lens use |
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Neurogenic ptosis
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CNIII deficit to levator or sympathetic innervational deficit to Muller
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What are some types of neurogenic ptosis
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oculomotor nerve palsy
Horner's Marcus Gunn jaw |
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Oculomotor nerve palsy
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neurogenic ptosis
trauma compressive lesions with complete ptosis, mydriatic pupils |
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Marcus Gunn jaw
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winking ptosis. neurogenic ptosis.
anomalous misdirected innervation of motor component of CN V between mastication muscle and ipsilateral branches of CNII to levator in which there is elevation of the ptotic lid with jaw movement |
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psuedoptosis
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mechanical ptosis
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What are some causes of psuedoptosis?
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lid edema, chalazion, dermatochalasis (excessive upper lid skin)
topical corticosteroid use hypotropia |
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MRD1
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margin reflex distance to upper lid
distance from corneal light reflex to upper lid is normally around 4-5mm |
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MRD2
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Margin reflex distance to lower lid
normal MRD2 is around 5mm |
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How do you exam levator function?
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measure excursions.
press hand on brow to eliminate frontalis action. place ruler at margin of upper lid while in down gaze and then measure position of lid margin in up gaze. normal excursion of levator function is 12-18mm with less than 4 mm indicates poor levator function |
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What are some causes of monocular diplopia
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refractive
media opacities dry eyes irregular cornea |
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What are some causes of binocular diplopia?
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Grave's disease
MG MS Trauma Decompensated phoria |
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What is the difference between palsy and paresis?
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palsy=complete
paresis=incomplete |
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What does CNIII innervate?
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iris sphincter
SR (upgaze) MR (ADduction) IR (downgaze) IO (upgaze) levator (elevation) |
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CNIII paresis results in...
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ptosis, down and out deviation, pupil dilation
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What does complete CNIII palsy look like?
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full ptosis
internal ophthalmoplegia of pupil and ciliary muscle down and out position from residual action of lateral rectus and superior oblique muscles |
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What does partial CNIII paresis look like
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some muscles affected more than others
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Painful CNIII paresis look like?
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pupil affected. consider compression by posterior communicating artery aneurysm-medical emergency with risk of subarachnoid hemorrhage
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What is CNIII paresis with pupil sparing?
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consider ischemic vascular diseases (diabetes, HTN)
resolution typically within 3-6 months-continue monitoring paresis and pupil status |
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What does CN IV (trochlear) innervate?
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superior oblique (intorts and depresses eye)
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CN IV paresis results in...
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vertical diplopia, hypertropia
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Congenital CN IV paresis
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patient adopts head position tilting away from affected side and imbalance increases when head is tilted to side of affected muscle--isolation of paretic muscle and diagnosis is made through Bielschowsky head tilt test and 3 step Park test
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Acquired CN IV paresis is from..
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vascular, trauma, MG, MS
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CN VI (abducens) supplies what muscle?
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lateral rectus (moves eye laterally)
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CN VI paresis results in...
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horizontal diplopia (esotropia), worse when patient looks towards affected side
patients compensate by turning face toward side of palsy to avoid using CN VI |
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acquired CN VI palsy is from...
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vascular, trauma, intracranial tumor, cavernous sinus, MG, MS, thyroid
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central defect
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involves fixation only (optic nerve or macula)
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cecocentral
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extends from fixation temporally to blind spot (optic nerve, toxic, nutritional)
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paracentral
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region next to but not including fixation (optic nerve)
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pericentral
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region symmetrically surrounding but not including fixation (optic nerve)
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arcuate
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corresponding to the nerve fiber layer
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altitudinal
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involves 2 quadrants either above or below fixation
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hemianopic
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involves field either to the right or left of fixation. either nasal or temporal with border aligned but does not cross the vertical meridian
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What are the signs and symptoms of cavernous sinus disease?
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vision loss, diplopia, ophthalmoplegia, orbital or hemicranial pain, pupil abnormalities, proptosis, conjunctival chemosis, orbital congestion, ptosis, dilated retinal veins, orbital bruit, ocular pulse amplitude
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What is converging into the cranial sinus?
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CN III, IV, VI 1st and 2nd deviations of V, sympathetic plexus and internal carotid
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etiologies of cavernous sinus disease?
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1 vascular
2. carotid-cavernous sinus fistula (CCF) 3. dural-cavernous sinus fistula 4. neoplasms 5. inflammations |
