HEENT Flashcards
Module 2
3 layers of the eye from outside to inside?
sclera, choroid, retina
Names for posterior and anterior portion of Sclera?
Posterior - Sclera
Anterior - Cornea
What nourishes the sclera?
lacrimal fluid and oxygen from atmosphere
Describe the choroid
dark vascular layer in posterior portion, prevents light from scattering inside the eye
Anterior portion of choroid and describe where it is?
Ciliary Body
ring shaped part of middle layer behind the iris
How much of posterior eye is covered by retina?
what does it have and what does that do?
2/3
photoreceptor convert light energy to nerve impulses
What does ciliary muscle control?
shape of the lens
2 parts of the ciliary body and function?
muscle - controls shape of lens
processess - secrets aqueous humor
3 parts of the choroid?
Choroid, Ciliary body, iris
What does the ciliary process do?
secretes aqueous humor
6 parts of middle eye?
choroid, ciliary body, ciliary muscle, ciliary processes, iris, pupil
3 things in the retina?
rods, cones, fovea
What type of inheritance is color blindness?
who does it most affect?
most common type?
X-linked recessive
Males > Females (8% to 5%)
Red-Green
What focuses the light entering the eye on the retina?
lens
What flexes the lens and when it adjusts to focus on objects of varying distances, what is that called?
Ciliary Muscle
Accomodation
Normal name for myopia?
where are rays focused in comparison to retina?
eyeball to long or too short?
fixed by what?
nearsightedness
in front of retina
too long
biconcave lens
Normal name for hyperopia?
where are rays focused in comparison to retina?
eyeball to long or too short?
fixed by what?
farsightedness
behind retina
too short
binconvex lens
what is astigmatism?
what does that do to light rays?
3 ways to correct it?
irregular curvature of the cornea or lens
bent unevenly
glasses, contacts, LASIK
Posterior Cavity runs from what to what?
filled with what?
when is it formed?
function?
describe floaters?
lens to retina
vitreous humor (jelly-like)
embryonic development
shape
strands that form with aging in posterior cavity
Anterior Cavity runs from what to what?
filled with what?
function of what its filled with?
cornea and lens
aqueous humor
supplies nutrients to lens and cornea
Anterior chamber runs from what to what?
Posterior chamber runs from what to what?
cornea -> iris
Iris -> lens
How many of each eye muscle do we have?
4 rectus, 2 oblique
What is strabismus?
Causes (3)?
if not caught early, what can it cause?
common symptom?
one eye deviates to one side
strong/weak muscle, cerebral hemisphere disease, thyroid disease
amblyopia
diplopia
what is amblyopia?
lazy eye
3 causes of nystagmus?
inner ear disturbance, CN lesion, Drugs
What is ptosis?
2 causes?
drooping of the eyelid
bell’s palsy, myasthenia gravis
What cranial nerve controls pupillary reaction?
CN 3
How many muscles does iris contain?
names?
function? sympathetic or parasympathetic?
2
Circular (sphincter) - contracts in response to parasympathetic (constricted pupil)
Radial - contracts in response to sympathetic (dilated pupil)
Pupillary Drug Reactions
Constricted?
Red? (3)
Dilated?
opiates
weed, benzos, sedatives
stimmies, and hallucinogens
Accommodation changes what?
By what muscle and what ligament?
Stimulated by what nerve?
what inhibits accommodation (3)?
symptoms? (3)
thickness of lens
ciliary muscle and suspensory ligament
CN 3, oculomotor nerve
aging, inflammation, disease of CN3
diplopia, blurred vision, headaches
What is presbyopia?
loss of accommodation due to aging, lens becomes larger/more firm, reduced near-sighted vision (parents with menu)
What is a cataract?
Causes? (5)
Symptoms? (4)
Treatment? (1)
cloudiness of the lens
aging, diabetes, sun damage, congenital (rubella/toxoplasmosis), trauma
decreased visual acuity, blurred vision, glare, decreased color perception
surgery, damaged lens is replaced by artificial lens
Leading cause of blindness in the world?
Leading cause of preventable blindness in the world?
Cataracts
trachoma
Glaucoma is caused by what?
What age group gets chronic glaucoma?
Caused by what due to degeneration of ____ and ____
What does higher IOP compress and what does that cause?
excessive accumulation of aqueous humor
> 50
outflow obstruction of aqueous humor, trabecular meshwork and canal of schlemm
compresses blood flow to retina causing ischemia
Glaucoma sx (2)
_____ appears _____ or _____ on exam?
treatment?
gradual loss of peripheral vision, “halos” around lights
optic disc eroded or cupped
eye drops to reduce secretion of aqueous humor or to constrict pupil
what is displaced and what does it move towards in closed angle glaucoma?
what can build up to cause this?
causes? (3)
symptoms? (4)
Exam findings? (2)
Type of surgery for this? and what does that surgery do
iris towards cornea
debris
developmental abnormality, aging, scarring (trauma/infection)
sudden onset eye pain, nausea, headache, blurred vision
pupil dilated/unresponsive to light / cornea appears bulging/cloudy
Iridectomy - removal of part of iris to open passageway for drainage into canal of schlemm
Two forms of macular degeneration? which is worse?
What does neovascular (wet) do to the eye?
What does dry do to the eye?
risk factors? (4)
Wet treatment?
Dry Treatment?
Neovascular (wet) and Atropic (dry)
Neovascular (wet) is worse
rapid loss of central vision
more common, progressive, limited night vision and difficulty reading
HTN, Smoking, DM, FHx
anti-vegF injections
antioxidant vitamins (lutein and zeaxanthin)
Macular degeneration is major cause of blindness in what age?
Where does it occur in the eye?
> 60 years old
fovea centralis
What does conjunctivitis cause inflammation of? (2)
sx? (3)
What virus causes conjunctivitis? sx?
4 most common pathogens that cause pinkeye?
conjunctiva lining the eyes and sclera
redness, itching, excessive tearing with discharge
adenovirus, watery d/c, redness, photophobia
Staphylcoccus, Haemophilus, Strep Pnuemoniae, M. Cat
What infection causes Trachoma?
Where does the infection occur? what does it produce?
two symptoms?
if not treated, what happens?
chlamydia trachomatis
upper eyelid, pearl-like follicles
scratchy eye, no exudate
eyelids scar and turn lashes inward causing recurrent corneal abrasions
Keratitis is inflammation of the what?
3 causes? and what is the most common pathogen
2 symptoms?
treatment?
what is the risk? _____ -> _____ -> _____
cornea
bacterial, viral (herpes simplex), or injury
severe pain and photophobia
optho referral
ulceration of cornea -> scarring -> permanent vision problems
what happens during retinal detachment?
3 causes?
3 symptoms?
treatment?
retina tears away from choroid, allows vitreous humor to flow behind causing worse tear, cells stop functioning because can’t get nutrients from choroid
severe myopia, aging, scar tissue that creates tension on retina
NO PAIN, floating spots, darkened curtain
surgery before irreversible damage to the dying retinal cells occurs
Purpose of rods? Location?
Purpose of cones? Location?
Purpose of fovea? Location?
peripheral vision and dim light, periphery
color and detail, center of retina
central vision, center posterior of retina
