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Abnormal Eyes

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sandyle909's version from 2016-09-06 02:31

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Normal Vision nasal side hits the temporal side (of retina); stays on the same side - doesn't cross optic chiasm
temporal side hits the nasal side (of retina); crosses the optic chiasm. ex: pituitary tumor = tunnel vision
Blind Eye defect at optic nerve (before optic chiasm - neither nasal nor temporal vision will make it to the brain)
Lesion at optic chiasm Ex: Pituitary TumorDefect in both temporal fields (tunnel vision)
Bitemporal hemianopsia
Lesion on optic tract Ex: Stroke, Tumor Produces defects on opposite side
Right Homonymous Hemianopsia Left optic tract defect
Left Homoymous HemianopsiaRight optic tract defect
Strabismus Misalignment of the eyes
Deviation of the eyes from their normally conjugate position
* If you seeabnormal corneal light reflection, do COVER UNCOVER TEST
Strabismus - Nonparalytic d/t an imbalance of EOM tone
deviation is constant in all direction of gaze
Esotropia v. Exotropia
Paralytic d/t weakness / paralysis of 1+ EOM
deviation varies depending on direction of gaze
CN has paralysis
Lateral Recturs (CN VI) moves gaze laterally
Superior Oblique (CN IV) moves gaze down and in
CN IIIAll of cardinal fields of gaze
Nonparalytic Strabismus - Esotropia eye moves inward (nasally) - LR weak
Corneal light reflect - light displaced laterally on affected eye
Nonparalytic Strabismus - Exotropia eye moves outward - MR weak
Corneal light reflect - light displaced medially on affected eye
Corneal light reflectNormal - same position on both eyes if they are conjugate
Cover- Uncover Test for Strabismus * If Corneal Light Reflect - abnormal (displaced medially or laterally)
Right esotropia (example) 1. Corneal light reflect ABNORMAL - LR weak, light displaced laterally
2. Cover Test - Right eye moves outward to fix on the light/ (left covered eye moves inward to the same degree!)
3. Uncover Test - Right eye deviates inward again, and left eye moves outward to fix on the light
CN III Paralysis - Paralytic StrabismusOculomotor n.
SO working, MR is NOT working
Dilated pupil, fixed on light & near effort
Ptosis of upper eyelid, lateral deviation of eye
CN IV Paralysis - Paralytic Strabismus - SO helps to look downTrochlear n., SO
MR is working, SO is not
Ex: Left CN IV Strabismus - Looking down to the right
The left eye cannot look down when turned inward. Deviation is maximum in this direction.
CN VI Paralysis - Paralytic Strabismus Abducens n., LR
R or L esotropia
at it's maximum when having the patient look in direction of the action of the weakened muscle
Near Far Accommodation Pt focus on object 10-12 cm away then focus on an object >6feet away
* Pupillary constriction - near effort; Pupillary dilation with - far effort / distance
"Narrows with near, dilates with distance"
Horner's Syndrome Sympathetic interruption
*1. Ptosis (drooping eyelid)
*2. Miosis (constriction of pupil)
*3. Anhidrosis (absent sweating of affected eye)
4. Aniscoria - unequal pupil size (>0.5mm diff)
pupils still react, just dilates more slowly
Tonic (Adie's) Pupil Parasympathetic interruption
sluggish reaction to light; mydriasis (dilated pupil)
Common cause of aniscoria
Orbital Contact Dermatitis Itchy rash to face
itching swelling around eyes R> L (after camping)
Periorbital/ Preseptal Cellulitis LG fever, swelling, redness, pain around L eye, unable to open L eye
increased nasal congestion, facial pressure / HA x 2 weeks priot to these s/s without any tx.
Chalazion *nontender; points inside lid
meibomian (sebaceous) gland, obstruction/inflammation
Hordeolum (Stye)*tender, pointing on eyelid margin (pimple/boil)
red infection near hair follicle of eyelash
Entropion - common in elderslid inversion
inward turning of the lid margin
irritation of conjuntiva and cornea
Ectropion - common in elderslid eversion
margin of lower lid turns outward
exposes palpebral conjuntiva
excessive tearing can occur
Dacryocystitis (lacrimal sac inflammation) swelling between base of nose and eye
Pingueculum (penguin) Yellow, triangular nodule on the bulbar conjunctiva on either side of the iris
harmless
vision WNL
Pterygium (DANGEROUS)Medial sclera - triangular thickening of bulbar conjunctiva that extends from inner canthus to cornea
may interfere with vision
Sclera Icterus yellow eyes
jaundice skin
elevated bilirubin
Exophthalmosabnormal protrusion of the eyeball
Grave's Disease (Thyroid dysfunction)
Xanthelasmafat / hyperlipidemia
demarcated yellow deposits of fat underneath the skin, around the eyelids
Conjuntivitisviral, bacterial (gooey), allergic (both eyes), irritant conjuntivitis
Episcleritisautoimmune
central nodule with radiation of vessels
usually self-limiting
Uveitis (iritis or iridocyclitis) *must refer * *hypopyon: inflammatory cells in anterior chamber of the eye
red *painful, photophobia, no discharge
risk: loss of vision
Infectious causes: Herpes, CMV
Systemic causes: Sarcoidosis, Juvenile Ideopathic Arthritis, Crohn's Disease
Subconjunctival Hemorrhage (benign) - extravasated blood in conjunctivacough, sneeze
asymptomatic
self-limiting
if recurrent, considering bleeding disorder
Hyphema *must refer *bleeding in anterior chamber!
secondary to trauma
Corneal Chemical Burn usually pt provides a history of - liquid or gas in eye
immediate, prolonged irrigation
must refer
Corneal Abrasion (with fluorescein staining) (something in right eye ever since mowing the lawn, photophobia, increased lacrimation, right eye pain)
Eye puncture - go to eye MD asap!puncture, wound with hemorrhage and asymmetric, non reactive dilated pupil
"filled with blood, dilated"
Cataractclouding (opacity) of the lens
painless, progressive vision loss
Ophthalmoscopic Exam Tipscompare findings BILATERALLY
inspect appearance of VESSELS
veins are larger than arteries
inspect for: HEMORRHAGE, EXUDATE, and edema of optic disc (papilledema)
inspect optic disc margin for any irregularities
Normal fundusarteries - light red, smaller
veins- dark red, larger
AV ratio 2:3 - 4:5
Hypertensitive Vascular Changes high blood pressure
1. copper wire - in the vessels closes to cup. Vessels get FULL/ TORTUOUS. Increase light reflex with coppery luster.
2. silver wire - when the vessel wall become too opaque the blood inside cannot be seen
3. A-V nicking- appearance of breaks in vein when artery and veins cross (a. overrides v., and makes it look like it's cutting it)
Hypertensive Retinopathy (Flame Hemmorhage/ Cotton Wool Patches)*Cotton Wool Patches aka: soft exudate - white gray ovid lesions with irregular (soft) borders
smaller than disc
cause: infarcted nerve fibers
DM retinopaty (Hemorrhages & Exudate) * Microhemorrhages seen along hard exudates
hard exudate are creamy/ yellow, appear bright and have well-defined borders
causes: DM, HTN
Proliferative DM Retinopathy (Neurovascularization) * development of new blood vessels arising from the disc and extending to the margins
more numerous and tortuous
associated: DM Retinopathy
Glaucoma with CuppingNormal cup to disc ratio 1:2
physiologic cup is usually less than 1/2 the diameter of the optic disc
Glaucoma - cup to disc ratio > 1:2
(d/t IOP)
Detached Retina *emergent referral to ophthalmologist* "curtain like shadow over vision"
flashes, floaters
risk of vision loss
Papilledema optic disc swelling that is caused by: ICP - INCREASED INTRACRANIAL PRESSURE
s/s: severe HA, n/v
Macular degeneration * area of the retina that absorbs the most light
degeneration of macula d/t - build up of drusen (cellular debris)
last step of eye exam = look directly at light
normal - reflection of light from macula
abnormal - light reflection decreases (as degeneration occurs)
memorize