Ophthalmology Flashcards
Diplolplia - define; monocular vs. binocular
- visual perception of two images of single object
monocular - diplopia persists when one of the eyes of covered
binocular - diplopia relieved when either eye covered
Monocular diplopia
- disappears when affected eye is covered and persists when unaffected eye is covered
causes - refractive, ocular surface, or structural intraocular lesioss are most common
- rare cerebral lesions reported
-> most common cause = cataract
Binocular diplopia
- disappears when either eye covered but present when both eyes open
causes - ocular misalignment due to lesion anywhere along pathway from central brainstem nuclei controlling eye movement, 3, 4 of 6 CN, at neuromuscular junction, or involving extra ocular muscles
-> most common cause = thyroid eye disease
Types of binocular diplopia
vertical - images above each other
horizontal - images beside each other
oblique
concomitant - ocular misalignment measures the same amount of prism diopters in all directions of gaze with cover testing
inconstant - misalignment measures different amounts in different directions of gaze (patient often reports images most separated in one position of gaze)
EOM CNIII
SR
IR
MR
IO
EOM CN IV
SO
EOM CN VI
LR
Diplopia worse in same gaze direction as field of action of EOM innervated by the cranial nerve indicates muscle _?
Muscle paresis (e.g. right 6th nerve palsy would produce worsened diplopia and limitation on up gaze)
Diplopia worse in direction of gaze opposite to field of action of an EOM indicates muscle _?
Muscle restriction (e.g. firbrosed inferior rectus will produce worsened diplopia and limitation on up gaze)
Which CN palsy would diplopia worsen with head tilt?
CN IV (right fourth nerve palsy would worsen diplopia on right head tilt)
Which CN palsy likely to result from increased ICP?
CN VI
CN III palsy
Urgent- r/o compressive aneurysm
- complete ptosis
- impaired elevation, depression, adduction, eye appears to be ‘down and out’
- dilated pupil
causes
- compression (aneurysm of posterior communicating artery)
- ischemic (brainstem stroke, Giant Cell Arteritis, microvascular schema from diabetes)
- trauma
CN IV palsy presentation
- looking to side affected -> affected eye looks straight
hypertropia of affected side (superior oblique muscle which affected in incyclotorter and depressor) is worse on contralateral gaze and ipsilateral head tilt - patient complains of vertical or torsional diplopia
causes
- trauma
- microvascular schema or giant cell arteritis
- compression (brainstem tumor)
- decompensation of congenital 4th nerve palsy
CN VI palsy presentation
- looking to towards nose with affected eye = adduct but impaired infraduction (not able to gaze down)
horizontal diplopia worse when looking toward side of palsied muscle and better when looking away from palsied muscle - eyes may appear isotropic in primary position
causes
- microvascular insult (schema from diabetes) or giant cell arteritis
- compression (tumor, aneurysm, raised ICP)
- trauma
Is spared pupil but otherwise complete CN III palsy more likely caused by microvascular or compression?
Microvascular because pupillary fibres travel on periphery of nerve and are first to be affected by mass lesion; image young patient without vascular RFs
Can temporal arteritis only present with ischmic optic neuropathy?
No - more likely to present with ischemic optic neuropathy but can present with any cranial nerve palsy, causing diplopia
- urgent investigations= ESR, CRP, CBC and temporal artery biopsy
- tx = high dose corticosteroids (prevent vision loss)
Imaging for diplopia
CT scan with fine cuts through orbit
MRI for intracranial lesions (optic chiasm), brainstem and posterior fossa pathology
Angiography (CTA, MRA, conventional) for pupil involving third nerve palsies
Red eye - orbital causes
Preseptal cellulitis - bacterial infection of superficial periorbital tissues and eyelid, not extending posterior to orbital septum, globe not involved, normal EOM without diplopia, normal pupils with no RAPD, can progress to orbital cellulitis
Orbital cellulitis - life-threatening infection often originating in adjacent sinuses and involving post-septal orbital tissue; can progress to cavernous sinus thrombosis or meningitis (caution fungal infection if DM)
Retrobulbar hemorrhage - collection of blood posterior to globe which compresses optic nerve and results in acute compartment syndrome, often trauma; eye appears prophetic with reduced EOM, sluggish pupillary reaction and RAPD, raised intraocular pressure, reduced vision; tx lateral canthotomy and cantholysis
Red eye - lids and lashes
Blepharitis - chronic inflammation of eyelid margin with scruf, telangiectasis, eyelash collarettes
Hordeolum - acutely inflamed eyelid gland
Chalazion - chronically inflamed meibomian gland
Red eye - conjunctiva and sclera
Conjunctivitis - commonest cause of red eye; bacterial, viral, autoimmune (Reiter syndrome), allergic; gonorrhoeal conjunctivitis is hyper acute purulent conjunctivitis which can lead to corneal perforation rapidly
Subconjunctival hemorrhage - common, pooled blood under conjunctiva, spontaneous onset, gradual resolution; if associated with trauma and encircles cornea 360degrees ensure globe rupture ruled out; check coagulation profile and offer lubrication and observation (rarely confused with Kaposi sarcoma)
Episcleritis - common, presents with foreign body sensation or mild irritation, often sectoral injection of superficial vessels, responds to topical lubricatoin
Scleritis - injection of deep scleral vessels, sclera with bluish color, associated headache and deep ache and soreness around eye, night pain, often associated with systemic autoimmune disease (RA)
Pingueculum/ pterugium - degenerative changes from sun exposure in conjunctiva, causing raised lesion at limbus often at 3 o’clock or 9 o’clock position
Foreign body - relevant hx, may have corneal abrasion with vertically-oriented epithelial defects, search upper and lower eyelid surfaces
Red eye - cornea
Infectious keratitis (HSV, bacterial ulcer) - white opaque infiltrate on cornea with associated injection of conjunctiva; with fluorescein staining, an epithelial defect (appears green) seen overlying white infiltrate; often poor contact lens hygiene or poorly managed abrasion
Foreign body - identify foreign body on cornea, ensure intraocular foreign body ruled out with orbital x-ray
Corneal abrasion- history trauma; epithelial defect seen by fluorescein uptake (appears green) over cornea with no white infiltrate; check pH to ensure no alkali or acid injury -> irrigate with Morgan lens if pH altered
Dry eye - prolonged contact lens wear or blepharitis; mild injection of conjunctiva and speckled pinpoint fluorescein uptake with no confluent epithelial defect - lubrication
Red eye - anterior chamber and iris
Acute angle closure glaucoma - severe unilateral periorbital headache, n/v; pt may see halos around lights, tender, hard eye with raised intraocular pressure >35, fixed mid-dilated pupil, shallow anterior chamber, diffuse conjunctival injection, corneal edema
Anterior uveitis - inflammation of iris and/or ciliary body; present with pain, redness, photophobia; pupil may be slightly constricted; WBCs and flare (proteinaceous aqueous) may be visualized in anterior chamber; etiologies such as trauma, secondary to corneal pathology, infections such as endophthalmitis, or autoimmune (JIA, ankylosing spondylitis, sarcoidosis, etc)
Hypopyon (collection WBCs) - possible endophthalmitis = severe inflammation within anterior chamber with layering of WBCs inferiorly creating crescent-shaped collection; r/o endophthalmitis (recent surgery or sepsis, bacteremia), or infectious keratitis if corneal ulcer present
Hyphema (collection RBCs) - crescent-shaped collection of RBCs inferiorly in anterior chamber, seen in trauma; assess intraocular pressure and ensure globe rupture r/o
Red eye - what must always be excluded?
Globe rupture (and r/o intraocular foreign body)
- 360 degree subconjunctival hemorrhage, peaked pupil, full thickness corneal or scleral laceration with prolapsed uveal tissue (dark tissue), obvious leak in setting of trauma
- no pressure should be placed on eye
- place protective shield over eye
- ensure tetanus UTD
- imaging by CT to r/o intraocular FB (MRI CI if metal FB suspected)
Red eye - lacrimal system
Dacroadenitis - swelling, erythema, tenderness of lacrimal gland in superolateral orbit
Dacryocystitis - erythema and swelling of skin overlying lacrimal sac inferomedial to eye with expression of purulent d/c from punch with pressure over lacrimal sac; ensure no surrounding cellulitis
Nasolacrimal duct obstruction - persistent unilateral tearing, d/c, crusting, recurrent conjunctivitis, recurrent dacrocystitis; commonly congenital and resolves in year 1 of life; may be acquired later in life
Common causes of red eye (CIF)
conjunctivitis (allergic, viral)
iritis
foreign body
Common pathogen in blepharitis
anterior - staphylococcus overgrowth
posterior - meibomian gland dysfunction
Common pathogen orbital cellulitis
bacterial - H. influenza, S. pneumonia, S. aureus, S. pyrogens
fungal - Phycomycetes and aspergillosis
Common pathogen conjunctivitis
Bacterial - S. aureus, S. pneumonia, H. influenza, Enterococcus, Chlamydia, N. gonorrhoea
Viral - Adenovirus, Coxsackie virus, HSV, HZV
Allergic - atopic, vernal, seasonal
Toxic - topical medications
Granulomatous - parinaud oculoglandular syndrome
Common pathogens keratitis
Bacterial - P. aeruginosa, S. aureus, S. epidermis, N. gonorrhoea, H. influenza
Viral - HSV, HZV
Fungal - Aspergillus spp, Fusarium spp, Candida spp
Protozoan - acanthamoeba
What sinuses surround the orbit?
Paranasal sinuses = frontal, maxillary, ethmoid, sphenoid
- infection or tumor can spread from sinuses (esp. ethmoid) into orbit causing orbital cellulitis or globe displacement with diplopia
Uveitis 7 systems to review to r/o causes
- rash (HZV ophthalmicus, syphilis)
- arthritis or low back pain (ankylosing spondylitis, Reiter syndrome, psoriasis, JIA)
- GI sx (IBD, Whipple disease)
- GU sx (tubulointerstitial nephritis, IgA glomerulonephritis, urethritis with Reiter syndrome)
- mouth and genital ulcers (Behcet disease)
- respiratory sx (TB, sarcoidosis)
- trauma (traumatic iritis, microhyphema)
Which red eye dx need urgent care?
- acute angle closure glaucoma
- endophthalmitis
- suspected globe rupture
- orbital cellulitis
- cavernous sinus thrombosis
- retrobulbar hemorrhage
- infectious keratitis
What lab for ankylosing spondylitis?
HLA-B27
What lab for sarcoidosis?
angiotensin-converting enzyme
+ CXR
What can topical steroids to eye exacerbate?
Corneal ulcers or dendrites from HSV epithelial keratitis
What CN affected with Herpes zoster ophthalmicus? What’s the sign?
CN V1
- nasociliary nerve involvement highly associated with ocular involvement
- > lesion on tip or side of nose = Hutchinson sign
What is Seidel test?
To test for laceration of cornea or sclera is full thickness and penetrated wall of the eye
- fluorescein stip over suspected perforation and use cobalt blue light - see stream of green fluorescein leaking from wound if +
Strabismus
misalignment of eyes leading to manifest deviation
Ocular misalignment
- phoria
eyes aligned under normal binocular vision
- misalignment develops when binocular fusion is disrupted (alternate cover test reveals deviation)
Ocular misalignment
- tropia
eyes are intermittently or constantly deviated under binocular viewing conditions
Ocular misalignment
- horizontal deviations
Esotropia - one or both eyes turn in
Exotropia - one of both eyes town outward
Ocular misalignment
- vertical deviations
Hypertropia - affected eye deviated upward relative to the other
Hypotropia - affected eye deviated downward relative to the other
Amblyopia
abnormal binocular development leading to decreased vision
- suspect when reduction in visual acuity is out of proportion to ocular findings alone
causes
- media opacities (congenital cataract)
- refractive error
- strabismus
Is esotropia or exotropia more common?
Esostropia
Is vertical strabismus typically comitant or incomitant?
Incomitant
Is vertical strabismus CN III, IV or VI palsy?
CN III or CN IV
What is Brown syndrome?
restriction of elevation in adduction due to scarring near trochlea or systemic inflammatory conditions affecting trochlea
What is double elevator palsy?
inability to elevate eye in adduction or abduction; must be differentiated from partial 3rd nerve palsy
A vs. V pattern strabismus
A pattern caused by overaction of superior oblique
V pattern caused by overaction of inferior oblique
What are tests for strabismus
Monocular cover/uncover test
Alternate cover test
Hirschberg test
What is monocular cover/uncover test
Detect presence of tropia and differentiate phoria from tropia
part 1 - cover eye and watch for movement in uncovered eye -> movement = tropia
part 2 - remove cover and watch for movement of initially covered eye -> movement = phoria (manifest when binocular fusion is interrupted)
What is alternate cover test
Detect presence of phoria and tropia - doesn’t differentiate between phoria and tropia
- one eye covered for few sec and then cover moved quickly to other eye, back and forth between the two eyes
- observe movement of uncovered eye -> moving to fixate on target signals presence of ocular misalignment (combined tropia and phoria)
What is Hirschberg test
Assess ocular alignment
- shine penlight from distance and identify whether light reflex is entered on pupil or deviated
- > light reflex deviated medially suggests eye deviated outward (exotropia)
- > light reflex deviated inferiorly suggests eye deviated upward (hypertropia)
Red reflex
- red flow emanating from ocular fundus that is observed through the pupil
- examine in neonatal, infants, and children
Leukocoria
Abnormal white reflex when assessing red reflex - raise suspicion for concerning intraocular pathology, e.g. Retinoblastoma, retinal pathology, congenital cataracts, etc
Treatment amblyopia
- significant refractive error corrected with glasses
- strabismic amblyopia = patch better-seeing eye + glasses if refractive components
- eye muscle surgery for strabismus after amblyopia managed
Anatomic approach to eye exam
Ocular adnexa -> cornea -> anterior chamber and iris -> lens -> vitreous -> retina -> vasculature -> optic nerve -> brain
Common causes of acute visual disturbance
- AACG
- hyphema
- subluxed lens
- vitreous hemorrhage
- central retinal vein occlusion
- central retinal artery occlusion
- anterior ischemic optic neuropathy
- migraine with aura
- pituitary apoplexy
- TIA
- occipital infarct/ hemorrhage
- blunt trauma
- penetrating trauma
etc
Blood and thunder fundus in what?
central retinal vein occlusion - extensive hemorrhage and cotton wool spots
What condition has cherry red spot in fovea and whitish oedematous retina?
central retinal artery occlusion
What is pituitary apoplexy
sudden severe headache with vision loss and cranial nerve palsies; occurs in setting of pituitary adenoma with sudden intralesional hemorrhage; life threatening
What will occipital infarct/ hemorrhage present with?
homonymous hemianopsia - may be posterior cerebral artery schema
Common causes of chronic visual disturbance
anterior segment
- corneal: dystrophy, scarring, edema, keratoconus
- lens: cataract (age-related, trauma, steroid-induced, metabolic)
- tumor: ciliary body or choroidal melanoma, choroidal metastasis, hemangioma
- macular: AMD, diabetic retinopathy, macular hold, choroidal dystrophy
optic nerve and chiasm
- glaucoma
- compressive: optic nerve sheath meningioma or glioma, pituitary adenoma, cyst, etc
- infiltrative: lymphoma or leukemia
- toxic/ nutritional: nutritional deficiencies (B1, B6, B12, folate), tobacco-alcohol, amiodarone, chloroquine, hydroxychloroquine, digitalis, ethambutol
- hereditary: Leber’s optic neuropathy (acute), dominant optic atrophy, recessive optic atrophy
- infectious
- radiation
Four common causes of chronic vision loss?
cataract
diabetic retinopathy
glaucoma
macular degeneration
Visual pathway
optic nerve -> chiasm -> optic tract -> lateral geniculate nucleus -> optic radiation -> optic lobe
Where is lesion in bitemporal hemianopsia and most common ddx?
optic chiasm
ddx (most common)
- pituitary adenoma
- suprasellar meningioma
- craniopharyngioma
- aneurysm of internal carotid artery
Where is lesion in right homonymous hemianopsia?
left optic tract OR
complete lesion of left optic radiation
Where is lesion in right homonymous superior quadrantopsia?
“pie in the sky” lesion, partial involvement of optic radiation in left temporal lobe (Meyer loop)
Where is lesion in right homonymous inferior quandrantopsia?
partial involvement of optic radiation in left parietal lobe
Where is lesion in right homonymous hemianopsia with macular sparing?
Posterior cerebral artery occlusion (watershed area with macula supplied by both PCA and MCA - sparing of MCA)
Is optic neuritis or retinal ischemia associated with pain?
Optic neuritis
What do you do if pt can’t read Snellen chart?
- Walk them closer
- if unable to read at 3ft then test ability to count fingers (CF)
- ability to detect hand motions (HM)
- ability to perceive bright light (LP)
Who are you comparing visual fields to when testing visual fields by confrontation?
Patient to your peripheral vision
What is fluorescein angiography? Indications?
Study blood flow in retina and choroid
- blue light (peak absorption of fluorescein at 465-490 nm) to take pictures of circulation through choroid and retinal vasculature (emit yellow-green light at 520- 530 nm)
- leakage from retinal vessels is abnormal
indications
- diabetic retinopathy
- renal vein occlusion
- AMD
- other
What forms the inner and outer blood-retina barrier?
- retinal blood vessels normally impermeable to dye (tight junctions) and form inner blood-retina barrier
- retinal pigment epithelium forms outer blood-retina barrier
Anisocoria
- different sized pupils
- no physiologic if >2mm difference
- measure in dark and bright light to identify abnormal pupil (smaller pupil abnormal if anisocoria increases in dark vs. larger pupil abnormal if anisocoria increases in bright)
Pathway of pupillary constriction
photoreceptors -> retinal ganglion cells -> optic nerve -> chiasm -> leave optic tract ->pretectal nucleus of midbrain -> Edinger-Westphal nuclei = CN III (bilateral innervation) -> parasymp neurons -> oculomotor nerve -> ciliary ganglion in orbit
short ciliary nerves leave ciliary ganglion to innervate pupillary sphincter muscle and cause pupillary constriction
What causes direct and consensual pupillary response?
Bilateral innervation from Edinger-Westphal nucleus
= light in one eye causes both pupils to constrict
Neurologic causes of abnormal pupils
Impaired pupil smaller (dilator muscle not functioning) = more anisocoria in dark
- Horner syndrome -> loss sympathetic innervation; central, pregnaglionic, or postganglionic lesion
Impaired pupil larger (pupillary sphincter not working) - more anisocoria in light
- CNIII palsy -> Adie pupil, traumatic mydriasis, pharmacologic dilation
What will you see if dilator muscle not functioning?
Impaired pupil smaller = more anisocoria in dark
What will you see if sphincter not working?
Impaired pupil larger = more anisocoria in light
Horner syndrome sx
- ptosis, miosis, anhidrosis
- dilation lag= slow dilation of affected pupil
- reverse ptosis = inferior lid appears to be slightly elevated
causes
- central = 1st order
- pregnaglionic = 2nd order
- postganglionic lesion = 3rd order
CN III Palsy sx
- ptosis, impaired elevation, adduction, infraduction, diplopia, pupil dilation
ddx
- ischemic
- compressive lesion (posterior communicating artery aneurysm, basilar artery aneurysm, orbital apex or cavernous sinus mass, uncal herniation -> Hutchinson pupil)
- traumatic
-> pupil unreactive to weak cholinergic agents but constricts to 1% pilocarpine
What condition is Hutchinson pupil seen in?
Uncal herniation
Relative afferent pupillary defect (RAPD)
- light of identical intensity is perceived as being of different intensity when presented before each eye because of a lesion often affecting the optic nerve
Swinging light test:
- > equal pupil constriction when light shone into eye perceiving normal light intensity
- > abnormal dilation of both pupils when light shone into eye perceiving less intense light
Ddx RAPD
- large unilateral retinal lesions (retinal detachment), ischemic CRVO, CRAO
- unilateral optic neuropathies: glaucoma, GCA, nonarterictic ischmic optic neuropathies, infiltration optic neuropathy, optic neuritis from demyelination, etc
- optic tract lesion can cause contralateral RAPD (asymmetric crossing fibers)
-> note cataract and amblyopia don’t cause RAPD
Light-Near dissociation
- pupils don’t constrict briskly to light but constrict more strongly to near stimulus
Ddx
- bilateral severe vision loss
- Argyll Robertson pupils (neurosyphilis)
- dorsal midbrain syndrome
- tonic pupil
- Adie tonic pupil
Argyll Robertson
neurosyphilis
- bilateral, small, irregular pupils
Inv - VDRL, FTA-ABS, CSF analysis
What is Parinaud syndrome
Dorsal midbrain syndrome
- lesion compresses dorsal midbrain - affects pupillomotor fibres but spares ventral fibres for near response
- dilated tonic pupils, limited up gaze, eyelid retraction, convergence-retraction nystagmus, skew deviation
What is tonic pupil?
damage to parasymp fibers of ciliary ganglion
4 major causes:
- local process (sarcoidosis, orbital tumor, trauma, temporal arteritis, surgery)
- neuropathic (DM, EtOH, Guillain-Barre, familial dysautonomia)
- infectious: neurosyphilis, HZV, HSV
What is Adie tonic pupil
- young (20-40s) females
- 80% unilateral
- lesion involves ciliary ganglion or short ciliary nerves - because efferent parasymp fibres leaving ciliary ganglion serving accommodation are more numerous than those serving pupillary constriction, lesions of ciliary ganglion may spare pupillary constriction to accommodation while impairing pupillary constriction to light
- affected pupil initially dilated (reduced parasymp innervation) and becomes smaller with time (little old Adie)
- features: light-near dissociation, sectoral palsy of iris causing vermiform movements, slow and tonic radiation after constriction to near stimulus, reduced accommodation
- cholinergic denervation super sensitivity occurs after days to weeks and may be demonstrated by pupillary constriction after instilling dilute pilocarpine with will not constrict normal pupil or dilated pupil of CN III palsy
