Packet 1 Intro Flashcards
amblyopia is when 1 or more of the following is present before age 6:
- amblyogenic anisometropia
- constant unilateral strabismus
- amblyogenic bilateral isometropia
- amblyogenic uni or bilateral astigmatism
- image degradation
prevalence of strabismus is about __%
3%
prevalence of amblyopia is about __%
2%
increased risk of 5 year incident visual impairment in better seeing eye of worse than 20/40
relative risk 2.7
strab/amblyopia diagnostic test sequence
- refractive status
- visual acuity
- monocular fixation
- deviation variables (including comitancy)
- sensorimotor fusion
- -1st degree: correspondance
- -2nd degree: sensory fision vs. suppression
- -3rd degree: stereopsis
- monocular accommodation and ocular motility
minimum case history for strab/amblyopia
- chief complaint
- signs/symptoms
- onset (time, type, associated conditions)
- patient eye history (esp. previous tx)
- patient medical history/ meds
- family eye/ med history
- patient/parent goals
signs/symptoms of strab
- covering one eye in bright sun
- head turns, tilts, and tips
- excessive blinking/rubbing eyes
1st question to ask in diplopia case history
-monocular or binocular
when is asthenopia (eye strain) common
-with intermittent strab or large phoria
constant strab longstanding usually few symptoms
time of onset for childhood strabismus is usually between what ages? and then adult increases prevalence after what age?
5-6 years old
again after 50 years old
what % of amblyopia cases are associated with abnormal refractive error
75%
independent risk factors for childhood exotropia
astigmatism
- 50-2.50: 2.50
- 50+: 5.88
aniso
- 25-0.50: 2.01
- 50+: 2.63
independent risk factors for childhood esotropia
SE refractive error aniso
> or = 1: 2.03
as hyperopia increases (+2.00 and greater especially), risk for esotropia increases greatly
to get the best refractive status, your goal is to:
control accommodation and scope on axis
goal: of accurate and valid objective refraction
problems with using tropicamide for cycloplegia
- dies off quickly (starting at 20mins)
- doesn’t fully knock out accommodation (still some residual accommodation left at 30 minutes)
pros/cons of atropine
- very long duration (can be up to a week)
- most complete paralysis
- most likely to have systemic reaction
side effects of atropine
- flushed
- blurry
- confusion/ delirious/ hallucinations
- hot
- dry
standard of case cycloplegia regimen
- typically anesthetic
- 1% cyclo 2 gtt separated by 5min
- dilating agent (phenyl or trop)
- wait about 30 mins to refract (may be earlier in light irises)
indications to cyclo
- 1st eye exam
- strab/amblyopia suspicion
- hyperopia
- greater than 1D of aniso
- suspected latent hyperopia
- high eso at near
- high lag on MEM
- suspected pseudomyopia
- uncooperative or noncommunicating patient
- suspected malingering, hysterical amblyopia
- acuity not corrected to predicted level
- subjective responses variable and inconsistent during manifest refraction
- Sx seem unrelated to nature degree of manifest refractive error
if your patient is cyclopleged and they look directly at your light during ret, what do you subtract from your gross to get your net?
your normal WD (-2.00)
set up for Mohindra ret
- dark room
- occlude other eye
- 50cm working distance
- patient looks at retinoscopy light
- subtract -1.25 from sphere power (leave cyl)
pros/cons for Mohindra ret
- allows for on-axis retinoscopy
- but not as good as cycloplegic retinoscopy
pros/cons for Mohindra ret
- allows for on-axis retinoscopy
- but not as good as cycloplegic retinoscopy
