Eye pathology Flashcards
Why are corneal abrasions so painful
The cornea is higher innervated
roughly how long will is take for a corneal abrasion to heal
24-48 hours
Where does regeneration of the cornea occur
the limbus
What is the most common pathogen in corneal ulcers
S. pneumoniae
pseudomonas
s. aureus
What is keratitis
Surrounding inflammation and disease process of the cornea. Typically associated with corneal ulcers
What is the most common type of conjunctivitis
Viral
What is viral conjunctivitis most commonly associated with
adenovirus
What may be seen on a slit lamp exam with viral conjunctivitis
follicles
What type of conjunctivitis is caused from herpes simplex / zoster
Keratoconjunctivits
What is the typical cause for bacterial conjunctivitis
If contacts: pseudomonas
Otherwise: S. Aureus, S. Pneumoniae, H. Flu, Moraxella Catarrhalis
What causes hyper acute bacterial conjunctivitis and how fast does it come on
Rapid onset of less than 12 hours
m/c associated with Gonorrhea
What is pterygium
Proliferative disorder hallmarked by the abnormal growth of fibrovascular conjunctival tissue
Where is pterygium seen in the eye
Along the nasal aspect and reaches toward the cornea
What is generally the cause of pterygium
UV light exposure
*causes changes in DNA and RNA
Also associated with HPV infections
What is the pathophys of pterygium
Light induced alterations of the limbus causes increased angiogenesis and abnormal tumor suppressor P53 and HLA expression
What is the cause of dacrocystitis
Infection (m/c Staph pneumoniae)
*generally s/p viral URI
If dacrosytitis is not treated, what can occur
periorbital or orbital cellulitis
What makes up the lens of the eye
crystalline proteins
What is occurring with cataracts
The crystalline proteins that make up the lens will lose their transparency over time
What are non-age related causes of cataracts
Trauma
uveitis
scleritis
radiation
medications
What are the common side effects of cataracts
Difficulty seeing at night
nearsightedness
frank opacification of the lens
*generally bilateral
What are the risk factors for cataracts
Age
Sunlight
Smoking / ETOH
malnutrition
metabolic syndromes
DM
HIV
high dose steroids
What is entropion
Internal folding of the lower lid
What can cause entropion
Post infectious (trachoma)
blepharospasm
What is trachoma
Chronic conjunctivitis d/t chlamydia trachomatis, leading to neovascularization and scarring of the lid
What is ectropion
eversion of the lower lid
What is the cause of ectropion
Age (tissue begins to relax)
*will present with tearing and dry eyes
What is a chalazion
non-infectious occlusion of the meibomian gland
What is a hordeolum
infection of the meibomian gland
What is orbital cellulitis
Infection of the orbit
*can be life threatening
What is the presentation of orbital cellulitis
Pain with eye movement
fever
normal visual acuity
proptosis
**does NOT involve the globe
What is a rare complication of orbital cellulitis
bacterial rhino sinusitis
*gains access from ethmoid sinus via the lamina papyracea
What is optic neuritis associated with clinically
MS
What is optic neuritis
inflammatory disease with demyelination of the optic nerve
*myelin breaks down secondary to an immune mediated reaction
-systemic T cell activation and then B cell activation against myelin
What is afferent pupillary defect associated with
pathology of the optic nerve
How do you test for afferent pupillary defect
swinging flashlight test (effect of the light will not get through to the CNS)
* if not present -> rule out optic neuritis
What causes glaucoma
Increased IOP due to the blockage of the canal of schlemm
What is normal IOP
12-22mmHg
What is occurring with glaucoma
Increased IOP will cause optic neuropathy and decreased visual flow to the retina
What are the types of glaucoma
Closed angle
open angle
What is acute closed angle glaucoma
Lens or peripheral iris blocks the meshwork/canal (m/c in people with shallow ant. chambers)
What are the symptoms of acute closed angle glaucoma
Monocular eye pain
blurry vision/vision loss
headache
conjunctival injection & cloudy cornea
What will the IOP be in someone with closed angle glaucoma
> 40mmHg
What is pipilledema
Edematous head of optic nerve bilateral from increased ICP
What will be seen on a fundoycopic exam with papilledema
Blurred disc margins
nerve head elevation
vascular congestion
What is macular degeneration
degenerative disease of the central aspect of the retina
*can be monocular or binocular
Progressive-> generally starts as dry and turns wet
How will a patient with macular degeneration present
with central vision loss
What increases a persons risk for macular degeneration
age
smoking
CV disease
HTN
obesity
sun exposure
What is atrophic macular degeneration
Dry
Generally will be mild and asymptomatic
How can you test for atrophic macular degeneration
Noticed on eye exam from the presence of druses
What is druse
yellow deposits made up of lipid and proteins in the macula
What is neovascular/exudative macular degeneration
Wet
Increased druses causes an inflammatory response. Pigmentation of macula increases and angiogenesis begins
these vessels are ‘leaky’ and the extra fluid can form pockets which distort typical anatomy of the eye = distorted vision
What is a retinal detachment
detachment between neurosensory retina from the retinal pigment epithelial layer/choroid
In what part of the eye is a retinal detachment most likely to progress
If it is along the superior aspect
if initially a larger size
if patient moves their head/eyes too much
What is the most common cause of retinal detachment
Vitreous detachment (posterior eye)
the vitreous mobility leads to cobweb floaters that are visualized by the patient
When is retinal detachment vision threatening
If it involves the central retina
Why can retinal detachment threaten vision
the separation leaves the neuronal layer avascular which causes photoreceptor degeneration
What is the most common type of retinal detachment
Rhegmatogenous tear
What is a rhegmatogenous retinal tear
A hole/tear in the inner neuronal later
*fluid accumulated between retinal layers
What is a tractional tear
Vitreous fibrous band pulls the retina away (no actual tearing)
-typically chronic and more likely to be asymptomatic
What is an exudative retinal tear
Fluid/blood from a retinal vessel leak, pushing the retina away from its typical anatomic position
*typically infection / inflammatory
What are black spots associated with in retinal detachment
vitreous hemorrhage
What does a patient have if they complain of feeling like their is a curtain coming over their vision
Retinal detachment
Where does retinal vascular occlusion occur
the first branch of the internal carotid (ophthalmic artery)
- if becomes occluded= retinal infarction
If a cherry red spot is seen on a fundoycopic exam with a pale retina, what is the likely diagnosis
retinal artery occlusion
What happens to the retina as it slowly infarcts from arterial occlusion
becomes pale
translucent
edematous
What are the signs and symptoms of retinal artery occlusion
Sudden, painless, monocular vision loss
*may have amaurosis fugax
