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66 Cards in this Set
- Front
- Back
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what does Rose Bengal stain
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1. epithelial surface that has been deprived of mucin protein protection
2. has exposed epithelial cell membranes |
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what is the color indicator for Rose Bengal?
what light is it viewed under? |
light bluish red->dark red->intense red
the deeper the hue, the more damaged the cells are WHITE LIGHT!! |
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what is Rose Bengal used to diagnose
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keratitis
severe dry eye |
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how will Rose Bengal look on a Herpes Simplex Keratitis patient
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brightly stains the damaged epithelial cells on the ulcer border
sometimes HSK wont stain with Fluorescein because the epithelial lesion has healed...but will stain with Rose Bengal |
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Difference between Lissamine Green and Rose Bengal
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Lissamine Green is LESS irritating but is NOT an instant stain (have to wait a little bit to stain)
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how does Fluorescein look under white light? cobalt blue?
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white light: yellow-orange
cobalt blue: green-yellow |
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what is Fluorescence?
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ability of certain substances to absorb light of certain wavelengths and emit light at longer wavelengths
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how does Fluorescein work?
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cannot penetrate that cell membranes of the epithelial cells nor the zonula occludens (tight junctions between epithelial cells) but it shows BREAKS IN THE CELLULAR SPACES
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clinically how does Fluorescein work if there IS epithelial loss?
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the dye can spread into the stromal tissue and enter the anterior chamber where it appears as a green aqueous flare
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how is Fluorescein used to assess retinal leakage
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Fluorescein is injected and the retina is viewed with cobalt blue. green-yellow spots is indicate leakage
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what are the 3 MAIN LAYERS of the tear film
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outer lipid layer*
middle aqueous layer inner mucin layer* *serves as protection from evaporation for the aqueous layer |
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how will dry spots look on a NaFl stained cornea (TBUT)
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black spots/streak against a solid green glow
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what is a normal TBUT? reduced?
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Normal: ~15 seconds
Reduced: <10 seconds |
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what should TBUT be performed in relation to the chronology of slit lamp
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prior to instillation of any topical anesthetics/dilating agents
hold their lids if the blink too much |
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(TBUT) how should you handle a patient with soft contacts lenses? hard contact lenses?
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soft contact lenses will absorb the dye, so you must rinse the dye out before putting the soft contact lenses back in
hard contacts lenses will NOT ABSORB the stain. |
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what do you do if you come across paradoxical findings
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if a patient complains of dry eye and shows OVER TEARING...retest with TOPICAL ANESTHETICS
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Advantages to Direct Ophthalmoscopy
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1.greatest patient comfort (rheostat)
2.you see as well as the patient sees out 3.portable 4.used w/ small pupils 5.most accurate estimation of media opacification 6.estimate patients refractive error |
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how do you enhance field of view for ophthalmoscopy
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Panoptic
Dilation Move closer to patient |
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what type of image is seen through ophthalmoscopy
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15X Magnification
virtual erect |
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who has more magnification myopes or hyperopes
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myopes: MORE magnification
hyperopes: LESS magnification AM=F/4, emmetropes=60D 3D Myopes=63/4=15.75X 3D Hyperopes=57/4=14.25X |
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what are the three filters in the ophthalmoscope
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Spot Size
Streak/Slit Cobalt Blue Filter Red-Free Filter (green light) |
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what is red free used for
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1.highlight small hemorrhages and nerve fiber layer loss
2.identify the position of a nevus |
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how does red free filter determine the position of a nevus
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nevi behind the RPE will appear red because RPE acts as a red filter, the red free filter will cancel red from the nevus
nevus or other area of pigmentation located on or in the retina will still be seen with the red free filter in place |
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disadvantages to direct ophthalmoscopy
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1.lack of stereopsis
2.close working distance 3.dependence on refractive error for clarity and magnification 4.small field of view 5.corneal reflex |
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what is a normal cup to disc ratio
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0.3-0.5
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pupillary pathway-sympathetic
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1st order neuron: Hypothalamus to ciliospinal center of Budge (C8-T2)
2nd order neuron: Preganglionic fibers exit, ascend sympathetic chain to SCG to synapse again 3rd order neuron: Postganglionic fibers follow carotid artery to orbit as long ciliary nerve |
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at the chiasm what % of the nerve cross and what % of the nerve uncross
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53% cross (nasal fibers)
47% uncross (temporal fibers) |
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what is the most common cause of rAPD? least common?
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MOST common: optic nerve condition
LEAST common: lateral geniculate region |
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pupillary pathway-sympathetic
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1st order neuron: Hypothalamus to ciliospinal center of Budge (C8-T2)
2nd order neuron: Preganglionic fibers exit, ascend sympathetic chain to SCG to synapse again 3rd order neuron: Postganglionic fibers follow carotid artery to orbit as long ciliary nerve |
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at the chiasm what % of the nerve cross and what % of the nerve uncross
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53% cross (nasal fibers)
47% uncross (temporal fibers) level of superior colliculus |
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what is the most common cause of rAPD? least common?
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MOST common: optic nerve condition
LEAST common: lateral geniculate region |
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what happens at the Edinger-Westphal nuclei (APD)
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both neuron group (nasal and temporal) synapses
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Parasympathetic:
how does the efferent pupillomotor fiber get to the ciliary ganglion |
efferent pupillomotor fibers course with CN III superficially then synapse at ciliary ganglion
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Parasympathetic:
where does the postganglionic parasympathetic pupillary fibers go |
connect to globe as short ciliary nerves supplying ciliary body muscle and iris sphincter muscle
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APD DOES NOT CAUSE
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ANISOCORIA
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what is the stance on BILATERAL APD'S...
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they DO NOT exist
APD's are RELATIVE to each eye...RAPD!!! |
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can CATARACTS, CORNEAL SCARS, VH cause APD?
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FUCK NO!!!
however: dense unilateral cataract can sometimes cause a pseudoAPD in the contralateral good eye |
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what is the grading APD
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3-4+
immediate dilation of pupil with swinging flashlight test 1-2+ no change in pupil size initially followed by dilation Trace: initial constriction, but greater escape to larger intermediate size with direct light stimulation compared to consensual stimulation (pupil size is smaller with consensual illumination) |
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0.3 log ND filter over AFFECTED EYE will enhance APD
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0.3 log ND filter over AFFECTED EYE will enhance APD
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how do you do APD testing in a patient with a fixed eye (dilated/constricted/traumatic)
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reverse technique:
1.shine light in fixed pupil and watch for miosis in other eye 2.move light over to non-fixed eye: if pupil dilates:APD in good eye if pupil constrict:swing light back to FIXED eye and watch good eye...if pupil dilates=APD in FIXED eye |
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what is angle kappa
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angle between papillary axis and the line of sight
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angle kappa is what type of visual testing
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MONOCULAR
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what is the purpose of angle kappa testing
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1.used with Hirschberg to determine STRABISMUS
2.OD compared with OS (monocularly) to determine ECCENTRIC FIXATION |
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POSITIVE KAPPA
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nasal displacement of CORNEAL REFLEX
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NEGATIVE KAPPA
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temporal displacement of CORNEAL REFLEX
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normal ranges of angle kappa
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1. ~0.5mm nasal to the center of the pupil (+)
2. +0.25mm to +0.6mm |
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in angle kappa and Hirschberg
1mm deviation from center is equal to how many diopter prism |
1mm=22 diopter prism
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Hirschberg is what type of visual testing
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BINOCULAR
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what is a normal result for Hirschberg
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symmetrical corneal reflex (no strabismus)
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what should you immediately perform if Hirschberg test yield a NON SYMMETRICAL reflex
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ANGLE KAPPA TESTING!!!!
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Hirschberg:
when the eyes are UNOCCLUDED, the reflex should remain in their monocular position...unless STRABISMUS is present |
Hirschberg:
when the eyes are UNOCCLUDED, the reflex should remain in their monocular position...unless STRABISMUS is present |
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what is near point convergence
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point in intersection of the lines of sight when the two eyes are maximally converged
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what type of target do you use when testing accommodation with NPC? convergence?
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accommodation: snellen one line above BCVA (blur and diplopia)
convergence: non-accommodative target (diplopia) |
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do you use habitual near Rx for NPC??
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YES!!!
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what is the subjective and objective results for NPC...which one do you use
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subjective: patient confirms diplopia
objective: doc. see one eye turn OUT use whichever comes first |
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what are NORMAL breaks and recoveries for NPC
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normal break: 3-5cm
normal recovery: +/- 3cm from break point abnormal break: greater than 12cm (receded) |
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unilateral cover test is used to detect...
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tropias
watch direct eye |
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alternating cover test is used to detect...
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phorias
watch NON-COVERED eye |
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for unilateral cover test you must allow both eyes too...on the target
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FIXATE!!!
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how do you orient the Maddox Rod when testing vertical deviation? lateral deviation?
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vertical: orient lines vertically
lateral: orient lines horizontally |
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Maddox rod is horizontal OD, the light appears left of streak...what is the diagnosis
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ESOphoria OD
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Maddox rod is horizontal OD, the light appears right of streak...what is the diagnosis
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EXOphoria OD
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Maddox rod is horizontal OS, the light appears left of streak...what is the diagnosis
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EXOphoria OS
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Maddox rod is horizontal OS, the light appears right of streak...what is the diagnosis
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ESOphoria OS
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Maddox Rod: the light is above the streak
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right eye hyper or
left eye hypo |
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Maddox Rod: the light is below the streak
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the left hyper or
right eye hypo |
