Common Conditions of the Eye Flashcards
what are the symptoms of nuclear sclerosis ?
makes objects appear less clear
patient sees more of red spectrum
what is a glaucoma?
increased pressure in the aqueous humour
what layer is the uvea layer ?
vascular layer
what three things make up the vascular layer ?
choroid
ciliary body
iris
what is inflammation of the uvea called?
uveitis
what is the main cause of total blindness?
cataract
what is a cataract ?
opacification of the lens
state three characteristics of the lens of the eye which makes it prone to the development of cataracts ?
- avascular - so later in life vessels may flow into the lens for nutrition can cause the lens to become hazy
- can’t shed old fibres - fibres present in the embryo are present at death
- no nuclei
what response is used to dilate the pupils?
sympathetic response
are all cataracts the same?
no
- everyones is different
what do immature cataracts look like?
spoke like opacities
state two secondary causes of cataracts ?
- steroid eye drops
- trauma
what type of cataracts are Sutural + Zonular cataract ?
childhood cataracts
do adult or childhood cataracts need to be treated more aggressively? and why?
childhood
- as the brain suppresses the image from the eye and can develop a lazy eye and become blind even if the cataract is treated
what are two causes of childhood cataracts ?
malnutrition
viral infection
are eye drops used to treat cataracts ?
no!!!
what is the len inserted into the eye during a cataracts operation?
PCIOL = Posterior Chamber Intra Ocular Lens
state the four stages of cataracts surgery
- small incision
- lens capsule opened
- cataractous lens removed by emulsification (phacoemulsification)
- plastic lens placed in capsular bag
what causes a glaucoma to form?
blockage of aqueous humour drainage
- therefore the pressure builds up
what structure does the aqueous build flow through at the angle of the anterior chamber ?
trabecular mesh
what channel does the aqueous fluid flow through after passing through the trabecular mesh?
schlemms canal
what structure produces the aqueous fluid?
ciliary body
what are the two types of glaucoma?
Primary open angle glaucoma
Angle closure glaucoma
is Primary open angle glaucoma unilateral or bilateral?
bilateral
is primary open angle glaucoma acute (sudden) or chronic (slow progressive) ?
slow progressive
will someone with primary open angle glaucoma have symptoms?
no not necessarily
- not symptomatic until late disease
what is the incidence of primary open angle glaucoma out of 100,000?
978
over which age does primary open angle glaucoma start to become more common?
over 40
what is a common cause for primary open angle glaucoma?
trabecular meshwork isn’t working properly so aqueous fluid can’t drain properly
what can be seen on an ophthalmoscopy when IOP is raised?
optic disc appears unhealthy, pale and cupped
what three things are required for a diagnosis of glaucoma ?
- raised IOP
- Visual field defects
- optic disc changes on ophthalmoscopy
what three types of eye drops can decrease IOP during POAG?
Prostaglandin analogues
Beta-blockers
Carbonic anhydrase inhibitors
what two types of surgeries can be done to treat POAG ?
Laser trabeculoplasty
Trabeculectomy surgery
what are the symptoms of ACG?
Sudden onset, painful, vision lost/ blurred; headaches
Red eye
Eye is very hard
what are the three causes of angle closure glaucoma ?
- large lens
- when sympathetic response is activated iris contracts and prevents fluid from escaping
- during inflammation of the choroid, sticky exudate on the lens prevents the fluid form escaping
– all over these increase the intraocular pressure
what surgical procedure can be done to by pass the aqueous blockage
iridotomy
- laser is used to make a hole in both periphery of the iris
what medication can be used to treat an acute episode of ACG?
- carbonic anhydrase inhibitors
- analgesia
- pilocarpine
- steroid eye drops
what are the 5 histological layers of the cornea?
- stratified squamous non-keratinised epithelium
- bowmans membrane
- stoma
- descemets layer
- simple squamous epithelium
what makes up the stroma of the cornea ?
regularly arranged collagen, no blood vessels
give an example of an inflammatory pathology of the cornea ?
corneal ulcers
give an example of an non-inflammatory pathology of the cornea ?
dystrophies
what is a corneal transplant called?
keratoplasty
does a corneal ulcer require aggressive treatment? why?
yes
- to prevent spread and scarring
which is the most difficult to treat?
- viral
- fungal
- bacterial
fungal
what are the 4 characteristics of corneal dystrophies ?
- bilateral
- opacifying
- non-inflammatory
- mostly genetically determined
state an example of autosomal dominant corneal dystrophy
lattice dystrophy
what occurs in lattice dystrophy ?
Deposition of amyloid material in the corneal stroma
what is the presentation of lattice dystrophy ?
eye irritation,
photosensitivity,
pain,
blurred vision
what is Fuch’s endothelial dystrophy?
Asymmetrical bilateral progressive oedema
what age range is most prevalent with Fuchs endothelial dystrophy?
60-70yrs
what causes the opacification during Fuchs endothelial dystrophy?
number of functional endothelial cells decreases
oedema occurs
not enough cells to keep the cornea clear
where are the three areas where uveitis can occur ?
Anterior uveitis - iris
Intermediate uveitis - ciliary body
Posterior uveitis - choroid
what are the three main causes of uveitis ?
- isolated illness
- non-infectious autoimmune
- infectious
what is the main complication of anterior uveitis ?
- inflammation can cause plasma and WBCs to leak into the aqueous humour
- these cells are then deposited at the back of the cornea
what is it called when plasma and WBCs settle posterior to the cornea ?
hypopyon
what symptom can be a result of intermediate uveitis ?
hazy vision and floaters
does the conjunctiva cover the cornea ?
no
what are the three parts of the conjunctiva called?
- palpebral
- fornical
- ocular
what makes up the conjunctiva sac?
the three sections of conjunctiva together
what are the symptoms of conjunctivitis ?
red, watery eyes
discharge
no loss of vision
what would the difference between bacterial and viral conjunctivitis be?
bacterial = yellow and pus viral = watery discharge
what glands are affected during a stye ?
- external
- internal
- external = sebaceous
- internal = meibomian
what gland inflammation is more painful during a stye?
meibomian gland
what is the hard connective tissue plate in the eye lid called?
tarsal plate
what substance do glands in the tarsal plate produce ?
oily substance which slows down evaporation so you don’t need to blink as much
what is an inflammation of the meibomian glands called?
hordeolum internum
what is the treatment of a stye?
- warm compress
- eye lid hygiene
- may need surgical incision
