Opthamology Clinical Correlates Flashcards
What are the 8 components of a complete eye exam?
- vision
- external anatomy
- pupils
- ocular motility
- anterior segment
- ophthalmoscopy (dilated)
- IOP
- visual fields
What are the 3 most common eye issues?
cataracts
macular degeneration
glaucoma
What is a cataract?
an opacity of the normally clear lens, caused by age, metabolic disorder, trauma or heredity
Surgery for cataracts isn’t done immediately. What are the 3 indications that surgery is necessary?
the severity of visual loss is great
functional needs of the patient
need to improve view of the posterior segment of the eye to care for other ocular pathology
After what age does macular degernation start becoming very common>
after age 50, but over 70 in particular
What segment of vision is lost in macular degeneration?
central vision
What are the two types of macular degeneration?
dry and wet
What are the signs of dry macular degeneration?
drusen, pigmentation changes, retina atrophy
WHat happens in wet macular degeneration
the defect develps in the deep retinal layers
growth o f blood vessens under the retina - they’re are new and leaky vessels that lead to edema and hemorrhage
the hemorrhage eventually turns fibrotic as it heals, leading to scarring and serious loss of vision
WHat are the treatment options for dry macular degeneration?
- quite smoking
- take AREDs nutritional supplements
- manage systemic diseases like HTN
What are the treatments for wet macular degeneration?
anti-vegf drugs like avastin to disrupt formation of new blooc vessels
conventional laser treatments if those don’t work
What vitamins are helpful in macular degeneration?
antioxidant vitamins - beta carotene, vitamin C and vitamin E
minerals zinc and copper
Why do newer vitamin formulas omit the beta carotene?
in smokers, beta carotene increases risk of lung CA
In general, what happens in glaucoma?
increased ocular pressure causes optic nerve loss
What are the two main types of glaucoma?
open angle and narrow angle (acute)
In general, what is the treatment for glaucoma?
lower the eye pressure via medical or surgical (laser) means
Describe normal aqueous flow.
the aqueous humor is formed near the ciliary body and then flows through the pupil over the iris down to the trabecular meshwork where it’s absorbed thorugh schlemm’s canal into the aqueous vein
then it drains into the episcleral vein in the conjunctiva
WHat happens in open angle glaucoma?
the trabecular meshwork degrades such that the aqueous humor doesn’t drain appropriately and pressure builds up
How will the appearance of the optic disc look different on exam in glaucoma?
you’ll get optic nerve cupping = enlarged cup due to loss of rim tissue
this indicates loss of optic nerve fibers
What are the signs of glaucoma?
pressure over 30 mmHg
optic nerve cupping = optic nerve tissue loss
shrinking of visual fields/progressive blind spots
What technique can be used to quantify loss of optic nerve tissue?
optical coherence tomography (OCT)
What are the two basic strategies of glaucoma medications?
decrease IOP by decreasing aqueous production or increases outflow
Which form of glaucoma is an eye emergency?
narrow angle = acute glaucoma
WHat are the symptoms of acute glaucoma?
acute onset
severe pain with loss of vision
maybe nausea, vomiting
red eye
cloudy cornea
extremely high ocular pressure, over 40 mmHg
What is the cause of narrow angle glaucoma?
closure of the angle between the iris and the cornea
these people just have a narrower angle and if the pupil dilates too far, it will push the irish right up against the trabecular meshwork such that fluid won’t be able to leave the eye at all
this builds up pressure in the eye, which pushes the iris even further into the meshwork, making it worse
What is the treatment for acute glaucoma?
- pilocarpine to constrict the pupil and pull the iris away from the angle
- acetzolamide (diamox) - a diuretic to pull fluid off to lower pressure
- Immediately refer to ophthamology for peripheral iridotomy
What happens in diabetic retinopathy pathogenesis?
increase glucose chronically
damages blood vessel walls
VEGF is release in response
this causes abnormal vasoproliferation
new vessels are leaky, so fluid leaks into the retina, fibrosis occurs, causing damage and potentially complete loss of vision
What are the clinical stages of diabetic reitnopathy?
nonproliferative diabetic retinopathy
preproliferative diabetic retinopathy
proliferative diabetic retinopathy
What are some of the signs you’d see in nonproliferative diabetic retinopathy?
blot hemorrhages and microaneurysms
cotton wool spots (small infarcts)
macular edema
hard exudates (lipids that leak out with fluid and are left there when fluid is resorbed)
What’s the gold standard for diagnosing diabetic retinopathy?
fluorescein angiography
you inject a dye and then take a picture as the die is in the eye
this allows you to see areas of fluid leakage form the vessels
can also use OCT
How can you treat the macular edema that comes with diabetic retinopathy?
intravitreal injections of steroid triamcinolone
What additional symptoms would you see in preproliferative diabetic retinopathy that aren’t present in non-proliferative?
intrareitnal vascular abnormalities and venous bleeding
What symptoms will you ultimatley see in proliferative diabetic retinopathy
neovascular vitreoretinopathy
vitreous hemorrhage = boat hemorrhage
fibrosis
retinal traction and puckering
What is the treatment for diabetic retinopathy?
panretinal photocoagulation
it’s basically laser treatments along the edges of the retina where it’s ischemic - hopes to stop the neovascularization
How often should diabetics have dilated eye exams?
yearly!!
refer upon diagnosis in type 2 and within 5 years of diagnosis of type 1
What happens in hypertensive retinopathy?
after continuous high arterial pressure, the arterioles will narrow and undergo sclerosis
What are the signs of hypertensive retinopathy?
flame hemorrhages
cotton wool spots
optic nerve edema in severe cases
arteriovenous nicking
“silver wire arteries”
What is the treatment for hypertensive retinopathy?
lower the blood pressure!
What are the 7 potential causes of sudden visual loss?
amaurosis fugax
migraine scotoma
retinal detachment
retinal artery occlusion
retinal vein occlusion
temporal arteritis
stroke
Describe amaurosis fugas
it’s a sudden loss of vision in ONE eye
lasts only minutes
painless
it’s usually temporary vascular insufficiency (TIA in the eye)
What workup should be done first in amaurosis fugax? What was the cause until proven otherwise?
cardiovascular workup first
CAD until proven otherwise
What would you see in the eye with amaurosis fugax>
embolic material within a retinal arteriole = hollenhortst plaque
Why is a retinal cholesterol emboli (amaurosis fugax) worrisome if it’s non-occlusive?
It’s a warning sign of future disaster in the vascular system
they’ll need a full carido workup including carotid US and echocardiogram
What are the characteristics of an ophthalmic migrainte?
often acephalgic
SCINTILLATING SCOTOMA is the hallmark
painless and temporary!
involves both eyes, causing hemianopsia
usually lasts 20-30 minutes
cause: spasm of arteriole in occipital cortex
What happens in retinal detachment?
sudden painless loss of partial vision in one eye
may be progressive but ALWAYS SUSTAINED - will NOT response spontaneously like an ophthalmic migraine will
often accompanied by floaters and photopsias
often spontaneous, but can be associated with trauma
Is retinal detachment for common in myopia or hyperopia?
myopia
What is the treatment for retinal detachment?
surgery
they can try to use laster demarcation of the retinal tear, but if that doesn’t work they’ll do a scleral buckling procedure
this involves pushing the eye wall against the retina, thus sealing the tear
What happens in retinal arterial occlusion?
sudden severe loss of vision in one eye
painless
vision loss is usually permanent, but may recover if treated rapidly
the cherry red spot indicates acute central retinal artery occlusion
What is the goal to treat an arterial occlusion acutely?
you want to push the block to the periphery where the damage will be less
rebreathe CO2 (dilate vessels)
timolol to lower ocular pressure
IV acetazolamide to lower IOP
massaging the globe with lids closed
Retinal vein occlusion can also occur. It this more serious or less serious than arterial occlusion? With what chronic conditions is it more common?
it’s less serious
more common with HTN and DM
What is the risk for sequellae with retinal vein oclusion
neovascular glaucoma - so refer to ophthamology, but not as urgently as you would with an arterial occlusion
What will the eye look like on examination with a central retinal vein occlusion?
a squashed tomato
Why is a branched retinal vein occlusion even less serious than a central retinal vein occlusion?
there is less damage to the retina, so there is less risk of serious vision loss
What is temporal arteritis?
it’s giant cell arteritis
an inflammatory conditions that causes HA, scalp tenderness, fever, weight loss, jaw claudicaiton, polymyalgia rheumatica, vision loss - maybe total blindness
What are the two ways temporal arterities can affect the eye?
vision loss from:
- retinal arteriolar occlusion
- optic nerve infarction
What are the potential deadly sequelae of temprla arteritis?
aortic aneurysms or stroke
WHat diagnostic tests are run in a temporal arteritis workup?
ESR and CRP will be positive
temporal artery biopsy to look for PMNs in the arterial walls
What is the treatment for temporal arteritis?
high dose systemic steroids immediately
In a visual CVA, visual field loss occurs bilaterally on the ____ side of the cortical lesion.
contralateral
What symptoms will you see in a CN3 nerve palsy?
ptosis
may have dilated pupil
affected eye down and out
(think of the hulk)
What happens in a CNIV palsy?
paralysis of the superior oblique muscle
so VERTICAL DIPLOPIA
slight elevation of the affected eye
very subtle - refer to ophtho
What happens in a CN6 palsy?
paralysis of the lateral rectus
affected eye is esotropic (turned in)
HORIZONTAL diplopia
movement of the affected eye is partially or totally limited in the lateral gaze
What are some causes of conjunctivitis?
chemical injury
angle closure glaucoma
ocular foreign body
corneal abrasion
uveitis
conjunctivitis - bacterial, viral, allergic
subconjucntival hemorrhage
What are the worst chemical injuries for the eyes?
alkali burns
these stick to proteins that stick to the eye and keep buring it - it will burn thorugh the cornea in an hour
rinse until pH is neutral
What are some symptoms of a corneal abrasion?
sensation of foreign body present - even if gone
pain
tearing
photophobia
HOw do you diagnose a corneal abrasion
you use fluorescein staining, which will stain any area of the cornea where there is an abrasion under UB light
What 2 things do you need to be careful that you don’t miss in a corneal abrasion?
a corneal laceration - these WILL get infected
hyphema - blood in the anterior chamber
refer both immediately
If you see linear abrasions of the cornea, what should you do?
flip the eyelid to see if there is a foreign body stuck under hte lid - rinsing won’t get it out
How doyou remove a metallic foreign body from the cornea?
you scoop it out with a small gauge needle
(if a rust ring is left, if may need to be burred out)
What do you NEVER prescribe for corneal abrasions?
topic anesthetics
they will NOT HEAL if they use this
What discharge iwll be seen with the following:
bacterial conjunctivitis
viral conjunctivitis
allergic conjuncitivis
bacterial = purulent
viral = clear
allergic = stringy with white mucus
What sort of injection will you see in allergic onjunctivitis?
diffuse = involving lids and often bilateral
longer history - little discharge, but what’s there will be ropey and mucoid
itchy eyes
Describe anterior uveitis = iritis.
you get ciliary conjunctival injection
no discharge
light sensitivity
deep, achy pain
anisocoria
keratic precipitates
often associated with systemic diseases
Describe a subconjunctival hemorrhage?
It’s a collection of blood on the surface of the sclera under conjunctiva
there is no inflammation, pain, or discharge
totally harmless, but patients freak out
(causes include trauma, eye rubbing, valsalva, cough/seeze, dry eyes)
