Blur Part 1 Flashcards
When does keratoconus develop?
onset in teens
This eye disorder is commonly associated with hay fever, atopic dermatitis, eczema or asthma
keratoconus
Can glasses correct an abnormal astigmatism?
no
What happens to the cornea with keratoconus?
The cornea progressively thins and bulges forward, creating a cone shape. Also creates an irregular astigmatism.
What is the treatment for keratoconus? (4)corneal
1- gas permeable contact lenses (regular glasses do not correct regular astigmatism)
2- keratoplasty
3- corneal cross linking
4- low vision aids
What is a keratoplasty?
corneal transplant
What is corneal cross linking?
surgery that strengthens the cornea
Keratoconus typically affects who?
females more often than males
Keratoconus is a _____ _________
developmental abnormality
Herpes Simplex Keratitis is from what virus?
herpes simplex virus
herpes simplex keratitis is an _________ disorder
inflammatory
Herpes simplex keratitis is a ___ ____ on the eye.
cold sore
Where does the virus that causes Herpes SImplex Keratitis lie?
sensory nerves of the face - trigeminal ganglion
What causes herpes simplex keratitis to reemerge? (3)
emotional stress, trauma, menstruation
What part of the eye does herpes simplex keratitis usually effect first?
epithelium (outer layer of the cornea)
What happens in recurrent episodes of herpes keratitis simplex?
-Lies dormant within facial nerve
-recurrent infections go deeper into the stroma and cause lasting damage
What is the reoccurrence rate of herpes simplex keratitis?
50% reoccurrence within 5 years
What is the eye disease caused by varicella virus (chicken pox)?
herpes zoster ophthalmicus
Symptoms of herpes zoster ophthalmicus
severe neuralgia (nerve pain)
vesicular eruption of skin (swollen, red, blisters)
Where does herpes zoster ophthalmicus live?
trigeminal nerve (main nerve to cornea)
Occular effects of herpes zoster ophthalmicus (4)
superficial ulcers
deep stromal ulcers
secondary glaucoma
paralysis of EOM (eye muscle)
What is the main cause of corneal ulcers?
misuse of contact lenses (sleeping in them, not changing them frequently enough)
What is the effect of corneal ulcers?
dependent on location - deeper the location, the worse the scarring
What is the disease that causes “swiss cheese” band across the eye
band keratopathy
What causes band keratopathy? (3)
tonacity of tears
pH
endothelial functionings
How to treat band keratopathy
corneal debridement (scraping epithelium off to reduce or remove it)
Main effect of band keratopathy
overall reduction in vision
What causes superficial punctuate keratitis “spk”? (3)
Adenovirus, herpes simplex, chemical injuries
Is superficial punctate keratitis spk curable?
no - treatable, not cureable
Effects of superficial punctate keratitis
small erosions within the epithelium
lesions are common
What is a recurrent corneal erosion?
When there is an injury to the cornea (fingernail, branch, papercut) and when your eye dries out it reopens.
What happens when you have recurrent corneal erosion?
More occurrences increases the likelihood of scarring
What is swelling of the cornea called
corneal edema
What happens to the cornea when you have corneal edema?
Swelling causes the loss of endothelial cells. This causes the cornea to get too much water in it and transparency is loss
Another term for corneal edema
Fuch’s dystrophy
Treatment for corneal edema
salt water drops to pull water out of cornea or hairdryer to eye
Another term for map-dot-fingerprint
corneal dystrophy
What happens with corneal dystrophy? (2)
cornea becomes unstable
transparency is lost
What usually causes bullous keratopathy
surgery gone wrong
What happens in bullous keratopathy? (5)
Damage to the cornea - cells lose the ability to remain clear
Edematous
loss of endothelial cells
painful epithelial edema
blur
Treatment for bullous keratopathy
no good treatment, best option is cornea transplant
Acid injury to eye
extensive burning (burns off front of eye)
Base/alkali injury to eye
more serious!
causes a chemical reaction within the eye and adheres to the corneal and conjunctival tissue.
Most common form of radiant energy that harms eyes
ultraviolet caused by tanning bends
What happens when eye is exposed to ultraviolet rays?
UV rays are absorbed into the cornea which causes burning and scarring of cornea
What happens with an infrared burn to eyes?
permanency reduced acuity
**this is like the “eclipse burn” from a solar eclipse earlier this year
Results of xrays on eyes (5)
damages tribecular meshwork
causes glaucoma, necrosis of the skin, loss of lashes, iritis
Hyphema
blood in anterior chamber
What causes hyphema
tear in iris
Results of hyphema (2)
vision is blacked out or blurred
Blood can scar the back of the cornea on the endothelium
what is iritis/uveitis
inflammation in the eye causes by the eye fighting something (likely lupis or another autoimmune disorder) or a corneal injury
Effects of iritis/uveitis (2)
cloudy anterior chamber (blur)
Increased eye pressure b/c tribecular meshwork is blocked
aniridia
partial or complete absence of iris
iris hypoplasia
iris does not form
congenital, bilateral, hereditary
Vision effects of aniridia (3)
reduced vision
photophobia
nystagmus
Why do people with aniridia have extreme photophobia?
The aperture of the eye (pupil) is absence so there isn’t any way for the eye to control how much light is entering the eye
Three visual conditions associated with aniridia
optic and macular hypoplasia
cataracts (earlier onset than typical)
corneal changes
When do cataracts typically form
Typically develop after 45 years old
What is the #1 cause of blindness in the world?
cataracts
Most common ocular surgery in the USA
cataract surgery
Three types of cataracts
nuclear sclerosis
cortical
posterior subcapsular
Effect of cataract
opacity within the lens of the eye
What is nuclear sclerosis
a cataract that causes discoloration of lens (yellowing)
Visual effects of nuclear sclerosis (3)
diplopia
refractive shift (can change from farsighted to nearsighted)
clouding of vision
What is a refractive shift
a change in how light is bent in the eye
Where is a cortical cataract located
anterior or posterior of lens
Vision of cortical cataract
opaque spokes (like bike spokes)
glare
least amount of visual effect of cataract types
What exacerbates posterior subcapsular cataracts?
diabetes
Where is posterior subcapsular cataract located
posterior capsule (blockage on back of lens)
visual effects of posterior subcapsular cataract (4)
most visually debilitating of cataracts
difficulty reading
glare at night
reduced vision in bright light
With this type of cataract a blockage on the center of the back of the lens negatively affects viewing and prevents light from coming into the eye because of its location
posterior subcapsular cataract
Two other types of cataracts that don’t have fancy names
congenital (at birth)
traumatic (injury or surgery)
At what age is retina fully developed?
7 years old
Congenital cataract viewing
clouding of lens
what do congenital cataracts effect? (2)
retinal development
causes amblyopia
treatment for congenital cataract
aphakia to pseudophakia or glasses
pseudophakia
fake lens
cataract surgery atime
8-12 minutes
what happens in cataract surgery
2.5-3 mm incision
ultrasonic probe breaks apart nucleus of lens
broken up parts vacuumed out
intraocular lens implanted
When was the first cataract surgery
1949
Types of intraocular lens implants
accommodating
astigmatism
side effect of cataract surgery
capsular phimosis
What is a capsular phimosis
secondary cataract that is a side effect of cataract surgery
What condition must be present for capsular phimosis to occure
patient must have a pseudophakic lens
What happens to vision with capsular phimosis
a haze develops on lens that causes reduced vision and glare
treatment for capsular phimosis
YAG laser
what is a vitreous hemorrhage
blood in vitreous
what is the most common cause of vitreous hemorrhage/
vitreous detachment
Besides vitreous detachment, these four things can cause a vitreous hemorrhage
proliferative diabetic retinopathy
vein occlusion with proliferation
retinal tear (w or w/o detachment)
trauma
Visual effect of vitreous hemorrhang
hazy to light perception acuity
what is optic neuritis
inflammation from the optic nerve
what is the most common cause of optic neuritis?
multiple sclerosis
Why is an eye doctor usually the person to diagnose multiple sclerosis?
Patient has rapid change in vision and eye doctor discovers optic neuritis
vision changes with optic neuritis
sudden change
reduced vision
Symptoms of optic neuritis (3)
pain upon eye movement
changes in pupillary reaction
loss of color vision
what is optic atrophy
Part of the optic nerve dies causing a loss of nerve fibers in the optic nerve (usually it is not known why)
What does optic atrophy cause? (4)
central scotoma
sometimes reduced peripheral vision
photophobia
altered color vision
