Eye Lecture Flashcards
Emmetropia
- Light rays fall directly on retina
- Normal vision
Myopia
- Light rays fall in FRONT of retina
- Nearsightedness
Hyperopia
- Light rays fall BEHIND retina
- Farsightedness
Astigmatism
Varying refraction due to irregular shape of cornea
cylindrical lenses needed as correction
Vital sign of the eye?
Visual acuity
Acute painless visual loss could be:
- Vitreous hemorrhage
- Retinal detachment
- Retinal artery occlusion
- Retinal vein occlusion
- Exudative macular degeneration
- Ischemic optic neuropathy
- Stroke
Vitreous hemorrhage
- “Spider webs” clouding vision
- A/w diabetes, sickle cell anemia
- Low red reflex, clouding of retina (or not seen at all)
Retinal detachment
- Photopsia/floaters
- “Curtain” covering vision
- Pts w/severe myopia
- Diplopia only goes away when the bad eye is closed
Photopsia
Flashes of light
Amaurosis fugax
- Transient painless monocular visual loss
- Occurs when blood clot or plaque blocks artery in eye
Retinal artery occlusion
- Sudden and nearly complete amaurosis fugax
- A/w carotid artery, valvular disease
- Vision limited to hand motion/light perception only
- Cherry red spot in macula, diffusely pale retina
Retinal vein occlusion
- A/w HTN, blood abnormalities (dyscrasias)
- Retinal hemorrhages, veins are tortuous and dilated
Exudative macular degeneration
- 60+ yo
- Slow, progressive
- Metamorphosia
- Retinal hemorrhage may be seen in macular region
Metamorphosia
Distortion of straight lines
Ischemic optic neuropathy
- Can be a/w HTN, diabetes
- Scalp tenderness, neck pain
- Marcus Gunn pupil, swelling of optic nerve head
Stroke
Normal exam of eye
Functional vision loss, painless
Corneal ulcer
-Hx of trauma or contact lens wear (esp during sleep)
Uveitis
- Inflammation of uveal tract (iris, ciliary body, choroid)
- Can be a/w sarcoid, TB, IBD, psoriasis
- Small pupil, sluggish or non-reactive to light, circumlimbal flush, low red reflex, usually unilateral
Circumlimbal flush
Circular reddening around cornea
Acute painful loss of vision could be:
- Corneal ulcer
- Uveitis
- Acute angle glaucoma
- Endophthalmitis
Acute angle glaucoma
- Older farsighted pts
- Blurry vision, haloes around light, pain
- Unilateral redy eye, non reactive pupil
Endophthalmitis
- Inflammation/infection of eyeball
- MC post surgical complication
- Redness, corneal edema, mucopurulent d/c, low red reflex
Chronic progressive painless vision loss could be:
- Refractive error
- Cataract
- Open angle glaucoma
- Atrophic macular degeneration
- Brain tumor
Binocular diplopia could be:
- CN 3, 4, 6 palsy
- Uncompensated strabismus
- Hyperthyroidism
- Myasthenia gravis
- Blow out fracture of orbit
MC cause of gradual visual loss?
Refractive error
Cataracts
Common in elderly
Low red reflex, visualization of retina is difficult, normal pupillary response
Open angle glaucoma
- MC in pts w/fam hx, myopia, DM, AAs
- Elevated IOP
Atrophic macular degeneration
- 60 yo+, may have fam hx
- Drusen (hyaline nodules) in retina
CN 3 palsy
- Usually painless diplopia
- A/w aneurysm, diabetes, tumor, trauma, uncal (brain) hernitation
CN 3 palsy PE findings
- At rest: eye can only gaze laterally, pupil dilated and may be fixed
- With herniation: unconsciousness, contralateral hemiparesis
- Droopy eyelid
How to confirm binocular diplopia?
Have pt close either eye and diplopia should resolve completely
CN 4 palsy
- Vertical diplopia, difficulty looking down
- A/w tumor, aneurysm, diabetes
CN 4 palsy PE findings
- Vertical diplopia
- Affected eye “sits” higher than other
- Head tilt as pt tries to compensate for vertical diplopia
CN 6 palsy
- Horizontal diplopia
- Tumor, DM, aneurysm, temporal arteritis
CN 6 palsy PE findings
-Eye “sits” with some esotropia (inward gaze)
Uncompensated strabismus PE findings
- If horizontal diplopia/deviation, exotropia OR esotropia
- If vertical, one eye will “sit” higher than other
Hyperthyroidism PE findings
- Proptosis w/decreased movement
- Results in diplopia
- Lid lag
Myasthenia gravis
- Weakness of facial muscles, upper limbs
- Worsens w/fatigue
Blow out fracture of orbits
- May result in CN entrapment
- SC air may be present
What can cause itching/burning of the eye?
Conjunctivitis (bacterial or viral)
What can cause FB sensation in the eye?
FB
Corneal abrasion
Dry eyes
Entropion
What can cause excessive tearing?
Ectropion
Entropion
Ectropion
- Outward turning of eyelid
- Tears do not reach drainage points
Entropion
- Inward turning of eyelid
- Excessive tear production
Visual acuity - distance from wall chart
20 feet
Visual acuity - distance from pocket Rosenberg chart
14-16 inches
OD
OS
OU
Right eye
Left eye
Both eyes
Interpret OD = 20/30 + 2
Pt read 20/30 line without mistakes and then got 2 right on the 20/20 line
Visual fields test
- Crude
- Each eye must be tested separately
- May only be possible to pick up significant deficits (not subtle)
Visual fields test - distance from patient
18 inches at the SAME level
If palpebral conjunctiva is pale, this could indicate:
Anemia
Arcus senilis
Whitish arc around edge of cornea in older patients (benign)
Pterygium
- Fleshy growth arising from conjunctiva over outer portion of cornea
- Usually nasal side
Cataract
- Opacity of the lens
- Pupil looks cloudy/hazy
- Reduced red reflex
Anterior depth chamber
- Iris is flat so you should see a small crescent of light on nasal side
- If there is a shadow, it would indicate a shallow anterior chamber due to bowing of the iris
Anisocoria
Unequal pupils
Normal in about 20% pts
Adie’s pupil
Large, very sluggish or no reaction to light, slow accommodation
CN 3 palsy pupillary reaction
No reaction to light or accommodation
Argyll-Robertson pupil
“Whore’s pupil”
Small, irregular pupils that accommodate but do not react (to light)
Horner’s syndrome pupil
- Small, but reactive to light and accommodation
- Ptosis is present on affected side
- Loss of sweating on affected side forehead
Marcus Gunn pupil
- Swinging flashlight sign
- 1st light into affected eye shows no reaction
- Then light in other eye affected eye constricts
- Shine back into affected eye and it dilates
How does a CN 3 palsy affect the eye movement?
Paralysis of medial, upward, downward gaze on affected side
- CN are not crossed so deficits are on the side of the lesion
- Also causes dilated non-reactive pupil and ptosis
How does a CN 6 palsy affect the eye movement?
Paralysis of lateral gaze on affected side
How does a CN 4 palsy affect eye movement?
Affected eye cannot look downward when turned inward
What is a rheostat?
Brightness/dimmer control on opthalmoscope
How do you perform the red reflex?
Tilt scope to ~15 degrees about 16 inches from patient
Venous pulsations of the eye
Sign of normal intracranial pressure
Venous pulsations of the eye are lost when:
ICP increases
Papilledema develops
Papilledema
Raised optic disc with blurred margins due to edema
T/F: Panoptic allows you to see entire fundus panoramically
True
Monocular vs. binocular diplopia
Monocular = problem with one of the eyes and it only is resolved when the bad eye is closed Binocular = EOM (should resolve when either eye is closed)
