Lecture VIII Flashcards
Corneal ulcers in a contact lens wearer = ?
Pseudomonas infection
MOA of Ketorolac = ?
NSAID–inhibit COX
What is amblyopia?
Decreased VA in the absence of detectable organic disease
What is strabismus?
the eyes do not properly align with each other.
What causes amblyopia?
Abnormal visual development–brain selects (favors) the aligned or least blurred image and suppresses the blurred or conflicting image caused by the lazy eye
Is amblyopia usually unilateral or bilateral?
Unilateral usually
True or false: there is a benign exam findings with amblyopia
True
What does the treatment of amblyopia depend on?
Plasticity of the visual system–youngins
When should treatment for amblyopia begin?
Prior to age 5
True or false: if not detected and properly treated, amblyopia carries on their entire life
True
What is the nucleus in the brain that atrophies with amblyopia?
Lateral geniculate nucleus
What is the role of the lateral geniculate nucleus?
a relay center in the thalamus for the visual pathway. It receives a major sensory input from the retina. The LGN is the main central connection for the optic nerve to the occipital lobe.
What are the three major etiologies of amblyopia?
- Strabismic
- Refractive (lens refractive error)
- Form-deprivation (cataracts/corneal scarring)
What is a tropia?
a misalignment of the two eyes when a patient is looking with both eyes uncovered
What is a phoria?
A latent deviation that only appears when binocular viewing is broken and the two eyes are no longer looking at the same object.
True or false: diplopia is usually found with strabismus
False–usually absent since the rain will turn off the visual pathway from that eye early on in development
What is the usual presentation of unilateral amblyopia? (3)
- Failed vision test
- Strabismus
- Parental concern
How can you detect amblyopia? (3)
- Assess red reflex
- Determine visual acuity
- Evaluate ocular alignment
Enlarged cornea is suspicious for what?
Tumor or glaucoma
How do you test for strabismus with a general inspection?
- Cardinal positions
- Epicanthus
- Facies
What are the two tests for strabismus?
- Corneal light reflex
- Cover/uncover test
What is pseudostrabismus?
Increased epicanthal folds may cause an appearance of strabismus
True or false: children do not see double
True
True or false: newborns should never have a sluggish pupil reflex
False–often the case d/t immature muscle control
What are the eye exams that should be done with newborns? (3)
- Corneal light reflex
- Red reflex
- Pupillary reflex
EOM may be uncoordinated for how long after birth?
3-4 months old
When are infants able to fix and follow with their eyes?
2 years
How do you perform a cover test with 2 year olds?
If cover eye, evaluate how child reacts–if objecting, then suspect problem
What is the “E” game that is played with 2-4 year olds?
Choose the right E amongst a series of Es
If a 2-4 yo vision is less than what acuity should you refer?
20/40
When is the cover/uncover test performed on children?
at 2-4 years
Is a photoscreener a substitute for visual acuity?
No
When should children be able to use the regular snellen eye chart?
Over age 5
Who treats amblyopia?
Ophthalmologists
How do you correct amblyopia?
- Clear visual pathway if needed
- Correct refractive error
How do you intensify the neural image to the visual cortex with an eye affected with amblyopia?
Occlusion therapy or penalization (defocus) the other eye
Success of the treatment for amblyopia depends on what factors (3)?
- Age
- Degree of amblyopia
- Compliance with patching
Does occlusion therapy eliminate strabismus?
No
What is the drug that is used to penalize the good eye in the treatment of amblyopia?
Atropine (antimuscarinic)
True or false: glasses alone can sometimes correct esotropia
True
What is the indication for a lateral canthotomy?
Increased pressure in the eye 2/2 orbital edema or retrobulbar hemorrhage
What does it mean when the strabismus is concomitant?
Angle of deviation is “constant” in all gazes
