Eyes and Visual Pathways Flashcards
What is in the eyes ROS when there is a positive response?
- sudden or gradual onset or pattern of change, type of change
- Associated symptoms: discharge/tearing, pain, redness, photophobia
- H/O prior eye issues
- Date and result of last eye exam
- Medications
Components of an Eye Exam
Visual Acuity
External
Internal
What is included in the visual acuity component of an eye exam?
Central/distant (CN II): Snellen or Rosenbaum
Peripheral: Visual fields (CN II)
What is included in the external component of an eye exam?
- Brows, lids, lashes, orbit, gaze (EOMs, nystagmus)
- Conjunctiva & sclera, cornea & lens, pupils
Nystagmus
- fine rhythmic oscillation of the eyes
- normal during extreme lateral gaze
What is included in the internal component of the eye exam?
retina
Horizontal Visual Field Defect
Occlusion of branch of central retinal artery
Monocular Visual Field Defect
Also called blind right eye
-lesion of the optic nerve
Bitemporal hemianopsia Visual Field Defect
- lesion at the optic chiasm and may involve only fibers crossing over to the opposite side
- visual loss involves the temporal half of each field
Homonymous hemianopsia Visual Field Defect
- same part of visual field is affected in both eyes
- lesion at optic tract
- multiple types
What are you looking for on the brows?
quantity, distribution, scales
What are you looking for on the lids?
- Palpebral conjunctiva
- Edema, color, position, lesions
- Orbicularis occuli closure
Dacryocystitis
- inflammation of the lacrimal sac
- swelling between the lower eyelid and nose
- acute: painful, red, tender
- chronic: obstruction of the nasolacrimal duct
- tearing is prominent and pressure on sac produces regurgitation of material
Ptosis
- drooping of the upper lid
- caused by myasthenia gravis, damage to CN III, damage to SNS supply (Horner’s disease), congenital
Exophthalmos
-protrusion of the eyeball triggered by autoreactive T lymphocytes
Entropion
- inward turning of the lid margin
- lower lashes irritate the conjunctiva and lower cornea
- common in elderly
Ectropion
- lower lid turned outward, exposing palpebral conjunctiva
- eye no longer drains well and tearing occurs
- common in elderly
Sty
Painful, tender, red infection in a gland at the margin of the eyelid
Chalazion
subacute nontender, usually painless nodule involving a blocked meibomian gland
- usually points inside the lid rather than on the lid margin
- not painful
Xanthelasma
slightly raised yellowish, well-circumscribed plaques that appear along the nasal portions of one or both eyelids
-may accompany lipid disorder
Retraction
- wide eyed stare suggests retracted eyelids
- symptom of hyperthyroidism
What are you looking for in the lashes?
Presence/absence of lashes, crusting and irritation combination with sty/chalzion
Blepharitis
swelling or inflammation of the eyelids, usually where the eyelash hair follicles are located
Abnormalities of EOM
- Imbalance muscle tone- congenital or CN disorder (lesions, trauma, MS, syphilis)
- Nystagmus (normal = extreme lateral gaze)
- Lid lag
What are the three layers of the eye?
- Fibrous (outer): sclera & cornea
- Vascular (middle): choroid, ciliary body & iris
- Inner: retina, optic & non-visual parts
What is bulbar fascia?
covers anterior part of cornea
How do you assess the conjunctiva and sclera?
- For: Color, injection, hemorrhage, foreign bodies
- Spread lids: sclera & bulbar conjunctiva
- Lid eversion (PRN): for palpebral conjunctiva
What ROS should you do if sclera is yellow?
GI ROS
What does blue sclera refer to?
Osteogenesis imperfecta, a congenital bone condition causing extremely fragile bones
What are you looking for when examining the cornea?
-Arcus, scar, pinguecula/pterygium, Kayser-fleischer ring (Wilson’s dz), shadows
Corneal arcus
- thin grayish whiet arc or circle not quite at the edge of the cornea
- accompanies normal aging
- usually benign
- in young people, suggests possible hyperlipoproteinemia
pinguecula
- harmless yellowish triangular nodule in the bulbar conjunctiva on either side of the iris
- appears frequently with aging, 1st on nasal and then on temporal side
pterygium
- triangular thickening of the bulbar conjunctiva that grows slowly across the outer surface of the cornea, usually from the nasal side
- reddening may occur
- may interfere with vision as it encroaches on pupil
Kayser-Fleischer ring
- golden to red brown ring, sometimes shading to green or blue
- from copper deposition in periphery of the cornea found in Wilson’s dz
- due to mutation in gene on chromosome 13
Corneal Scar
- superficial grayish white opacity in the cornea
- secondary to an injury or inflammation
- variable size and shape
- do not confuse with cataracts, which can only be seen through pupil
Cataracts
-opacities of the lenses visible through the pupil
Assessment of Pupils (CN II & III)
- Size (3-5mm), shape, symmetry (Miosis, mydriasis, Anisocoria)
- pupillary reaction
Miosis
constriction of pupils
Mydriasis
dilation of pupils
anisocoria
- pupils not the same size
- benign if normal pupillary reaction
- Tonic Pupil (Adie’s Pupil), CN III paralysis, Horner’s, Argyll Robertson
Tonic Pupil (Adie’s Pupil)
- impaired PSNS to iris
- pupil is U/L, large, regular
- reaction to light severely reduced and slowed, or absent
- near reaction is slow, but present
- deep tendon reflexes decreased
- slow accommodation = blurry vision
Oculomotor Nerve (CN III) Paralysis
-dilated pupil is fixed to light and near effect
-ptosis of upper eyelid
lateral deviation
Horner’s Syndrome
- affected pupil is small, but reacts briskly to light and near effort
- ptosis is present, with possibly loss of sweating in forehead
- when congenital Horner’s: iris is lighter in color than its fellow
Argyll Robertson Pupils
- small, irregular pupils
- accomodate but do not react to light
- seen in CNS syphillis
Parts of the fundus
- Optic disc
- Macula lutea
- Fovea
- Blood vessels
Normal Optic Disc
- Yellow-orange to creamy pink
- Well defined margins
- Physiologic cup (Usually ½ size of disc; may or may not be visible)
papilledema
- Pink, hyperemic
- optic disc appears swollen & blurred margins
- Physiologic cup is not seen
- may have history of trauma, pain in back of eyes
What is important to look for in the blood vessels of the fundus?
- AV crossing, AV nicking, tapering
- Copper wiring, silver wiring
- Hemorrhages (deep, superficial & preretinal)
- Neovascularization
- Microaneurysms
AV nicking
-vein appears to stop abruptly on either side of the artery
AV crossing
- vein crossing beneath the artery
- can be seen right up to the column of blood on either side
Tapering
the vein appears to taper down on either side of the artery
Cooper Wiring
- arteries become full and somewhat tortuous
- develop an increased light reflex with bright coppery luster
Silver Wiring
-portion of narrowed artery develops such an opaque wall that no blood is visible within it
Deep Retinal Hemorrhaging
- small, rounded, slightly irregular red spots that are sometimes called dot or blot hemorrhages
- occur in deeper layer of retina than flame shaped hemorrhages
- commonly caused by diabetes
Superficial Retinal Hemorrhaging
- small linear flame-shapped red streaks in the fundi
- shaped by superficial bundles of nerve fibers that radiate from the optic disc
- see in hypertension, papilledema, occlusion of the retinal vein
Preretinal Hemorrhaging
- develops when blood escapes into potential space between retina and vitreous
- larger than retinal hemorrhages
- obscures any underlying retinal vessels
- red cells settle when patient is erect
Neovascularization
- formation of new blood vessels
- they are more numerous, more tortuous, and narrower than other blood vessels in the area
- common in diabetics
- may obstruct vision
Microaneurysms
- tiny, round, red spots seen in and around macular area
- minute dilations of very small retinal vessels
- associated with diabetes
When looking at the fundus with the opthalmoscope, what are you looking for?
- “cotton wool” patch (soft exudates)
- hard exudates
- Drusen
- Macular Degeneration (wet and dry)
Cotton-Wool Patches
- white or grayish cotton like patches
- moderate in size but usually smaller than disc
- result from infarcted nerve fibers
- associated with HTN, DM
Hard Exudates
- creamy or yellowish bright lesions with well defined “hard” boxers
- small and round and occur in clusters or circular/linear/star-shaped patterns
- caused by HTN, DM
Drusen
- yellowish round spots that vary from tiny to small
- edges may be soft or hard and are haphazardly distributed
- appear in normal aging, but accompany other conditions (i.e. age-related macular degeneration)
- seen through peripheral fields
Macular Degeneration
- cause of poor central vision in older adults
- Wet (Exudative):neovascular macular degeneration; common in diabetics
- Dry (atrophic): more common and less severe
Examples of Age-Related Changes in the Eyes
- VA: glare sensitivity, presbyopia, macular degeneration
- Lids: entropion
- Growths: xanthalasma, pingecula & pterygium
- Cornea/lens: arcus, cataracts, glaucoma
- Precancerous/cancerous skin changes
What are the four types for anisocoria?
Tonic, CN III paralysis, Horner’s, Argyll Robertson
What are hard and soft exudates associated with?
HTN and diabetes
In younger people what is a corneal arcus associated with?
hyperlipoproteinemia
Risk Factors of Cataracts
-risk factors: old age, smoking, diabetes, corticosteroid use
What does hypertension, papilledema, occlusion of the retinal vein have in common?
seen in superficial retinal hemorrhaging
What type of macular degeneration is associated with diabetics?
Wet or Exudative
Fortifications
zig-zag arcs of light in vision
