Ch 15 Eyes Flashcards
CN VI (abducens) innervates \_\_\_\_ muscle CN IV (trochlear) innervates \_\_\_\_\_ muscle CN III (oculomotor) innervates \_\_\_\_\_ muscles
CN VI: lateral rectus (abduct)
CN IV: superior oblique (in and down)
CN III: all other nerves (superior, inferior and medial rectus, interior oblique
Corneal reflex involves CN ___ and ____
CN V (trigeminal): afferent CN VII (facial): efferent
intraocular pressure: balance between amount of ____ and resistance to its outflow at angle of _______
amount of aqueous humour
angle of anterior chamber
optic disc: where fibres from ____ converge to form _____ nerve
retina
optic nerve
retinal arteries are ____ and ____ compared to veins, grow ______ in calibre near periphery
bright red, narrower
smaller in calibre as they approach periphery
macula is on the ____ side of fundus
contains fovea which is area of ______ vision
temporal
sharpest vision
Pupillary light reflex
CN ___ is afferent
CN ___ is efferent
CN II afferent
CN III efferent
Accommodation tests for _____ and ______
convergence and pupillary constriction
macular degeneration is loss of ____ vision
glaucoma is loss of _____ vision from damage to ____
macular degeneration: central loss
glaucoma: peripheral loss, damage to optic nerve
Open angle glaucoma:
- aqueous humour is _____
- symptoms:
Closed angle glaucoma:
- aqueous humour is ____
- symptoms:
Open angle:
- aqueous humour slow to drain
- virtually no symptoms
- peripheral vision loss often unnoticed
Close angle:
- angle is blocked, no drainage
- sudden increase in IOP
- blurred vision, light sensitivity, halos around lights, nausea
halos around lights may occur with ______
narrow angle glaucoma
strabismus is deviation in ______ axis of eye
antero-posterior axis
what is anisocoria?
pupils of two different sizes
Myopia: light rays focus ____ of eye
-compensate with ____diopter
Hyperopia: light rays focus _____ of eye
-compensate with ____ diopter
Myopia: front of eye
-negative
Hyperopia: behind (if they could pass through)
-positive
What is normal cup to disc ratio?
cup width is <0.5 diameter of disc
What is normal macula size?
1 DD, located 2DD temporal to disc
what are pingueculae?
yellowish elevated nodules from thickening of bulbar conjunctiva
- from prolonged exposure to sun, wind, dust
- occur at 3:00 and 9:00
What is arcus senilis?
grey arc around limbus from deposit of lipid
no effect on vision
What is blepharitis? signs and symptoms?
inflammation of eyelids
- red, scaly, greasy flakes, crusted eyelid margins
- staph or seborrheic dermatitis at eyelid
symptoms: burning, itching, tearing, FB sensation, some pain
What is a chalazion? signs and symptoms?
beady nodule on eyelid
-infection/cyst of meibomian gland
-NONtender, firm, discrete swelling
if inflamed it will point INWARD (not eyelid margin)
What is a hordeolum (stye)? signs and symptoms?
Localized staph infection of hair follicles at eyelid margin
- painful, red, swollen
- pustule at eyelid margin
What is dacrocystitis vs dacroadenitis?
dacrocystitis: infection and blockage of lacrimal sac and duct
- pain, swelling, redness to inner canthus
- pressure will produce pus from puncta
dacroadenitis: infection of lacrimal gland
- pain, redness, swelling to outer third of upper eyelid
- from MMM (mumps, measles, mono)
What is miosis vs mydriasis?
Miosis: constricted fixed pupils
-from pilocarpine drops for glaucoma, narcotics, iritis, damage to pons
Mydriasis: dilated fixed pupils
- from dilating eye drops, acute glaucoma, trauma
- heralds CNS injury, arrest
What is Argyll Robertson Pupil?
- no reaction to light, constrict with acccomodation only
- small and irregular
- with neurosyphilis, brain tumour, meningitis, chronic ETOH
What is Horner’s syndrome?
- lesion of sympathetic nerve
- unilateral small regular pupil
- reacts to light and accommodation
- ptosis and anhidrosis also present
What is a tonic (Adie’s) pupil?
- sluggish reaction to light and accommodation
- usually unilateral
- no pathological significance
Signs and symptoms of acute glaucoma?
- circumcorneal redness around iris
- pupil DILATION
- cornea looks steamy
- sudden clouding of vision and sudden eye pain
- halos around lights
- *critical finding, needs emergency intervention**
Signs of symptoms of iritis
- dull red halo around iris and cornea (pronounced around iris)
- may have irregular pupil shape from swelling
- marked photophobia
- constricted pupils
- blurred vision
- throbbing pain
- critical finding, needs immediate referral
What is a hyphema?
- blood in anterior chamber
- result of blunt trauma
- suspect scleral rupture or major intraocular trauma
- *emergency**
What is a hypopyon?
- purulent matter in anterior chamber
- with iritis and anterior chamber inflammation
- emergency*
What are signs of papilledema?
- congestion and elevation of optic disc, blurred margins, hemorrhages
- absence of venous pulsations-
- visual acuity NOT affected
- serious sign of rising ICP
Scleral icterus extends up to _____ and is indicative of ________
extends up to cornea
-indicative of jaundice
