Flashcards in Exam Techniques Deck (23):
Limitations of Fix, Follow, Maintain?
NOT QUANTITATIVE - not accurate for MILD vision loss, may show fixation preference w/o amblyopia
Limitations of FPL (forced choice preferential looking?
NEAR ACUITY ONLY assessed - won't ID any pt over -2.00D
-UNDERestimates acuity loss d/t amblyo, Rf error and macular pathology (gratings large enough to be OUTSIDE macular area)
-time consuming, expensive
Limitations of Lea grating PADDLES?
-examiner's FACE can be distracting; examiner bias
Cardiff acuity used for which two populations? Test distance? Main limitation?
-toddlers, individuals w/ disabilities
-limitation: VERY poor at determining Rf error.
Three GOOD tests to use to check VA in peds:
Lea, Patti pics, HOTV
-all are WELL standardized, and available in logMAR forms
Three LIMITED (not so good) acuity methods? WHY Is each not so good?
-Tumbling E - laterality (R/L) may be an issue - otherwise good
-Broken Wheel (Landolt C) - 50/50 chance - it's only two forced choice
-Allen figures - NOT STANDARDIZED!! - NO consistent, critical detail
"____'s Technique" - a NEAR retinoscopy technique - describe it.
-Ret @ 50cm, NOT under cyclo, in a completely DARK room, subtract correction factor
-PROBLEM: UNDERESTIMATES HYPEROPIA!!
What is the MOST ACCURATE way to assess a kid's TRUE refractive error? What's the main problem with it you must be conscious of?
-Problem: retting off axis. OK to have kid look directly @ retinoscope
Major problem with Autorefractors in peds population (what do they underestimate?)
-MOST accurate for what type of Rf error?
-accurate for ASTIGMATISM; esp AXIS.
Bruckner can quickly provide all of the following....
-Presence of STRAB (strab eye = brighter)
-Presence/equality of RF ERROR
-Presence of MEDIA OPACITY
-Presence of PUPIL SIZE ASYMMETRY.
-Insight as to whether amblyopia may be present.
Which TYPE of refraction is recommended in peds? Hints?
TRIAL FRAME refraction w/ peds frame (phoropter=accommodation/distracting)
-Use ret as starting point
-make them READ LETTERS - not just "is it clearer"
Most appropriate cyclo potency in kids
1Y/O: 1.0% cyclo
Premie/LBW = cyclomydril (0.2% cyclo, 1% phenyl)
Sensitivity in picking up a strab is just as high when using an accommodative target as using an interesting light.
FALSE - only ACCOMM TARGET will p/u strab.
Is a dilated eye exam recommended, or required?
STANDARD OF CARE - DILATE EVERY PATIENT at least q 2 yrs. In peds, MUST do it on first eye exam (including BIO!)
Can OKN be "normal" even when pt is FUNCTIONALLY blind? How about when they have a massive CENTRAL scotoma? How about if it's a peds pt w/ a nystagmus?
YES-YES-hard to interpret if nystagmus present.
--so, it has its limits
RP and Usher's syndrome will cause WHAT changes to the ERG?
Reduced SCOTOPIC response
Cone-rod dystrophy and achromatopsia will cause what changes to an ERG?
No cones/cone pigments - difficulty in light
-Decreased PHOTOPIC response
Albinism will cause what change to the ERG?
No pigment - odd one - EXCESSIVE SCOTOPIC response
Congenital stationary night blindness will completely eliminate WHICH ERG wave?
B-wave (Bipolar, Mueller)
Leber's congenital amaurosis will cause what change to the ERG?
Honey badger - reduces PHOTOPIC AND SCOTOPIC ERG.
What, specifically, does an EOG measure?
Health of the RPE - but specifically, the VOLTAGE difference b/w the cornea and the PP.
-Recall: Arden ratio - want high--> anything
VEP - a direct measure of which part of the visual pathway?
Visual CORTEX - most commonly used to bypass orbit and assess cortical VA potential.