Diagnostic Testing Flashcards
What are the 5 phases of Fluorescein angiography?
- Choroidal (pre-arterial)
- Arterial (early)
- Arteriovenous (capillary, early)
- Venous
- Recirculation (late)
FA interpretation: blood
Hypo or hyperfluorescence?
Hypo
* obstruction/ blockage
FA interpretation: vascular occlusion
Hypo or hyperfl?
Hypo
* inadequate perfusion of tissue (filling defect)
On FA, types of hyper-fluorescence (4)
- pooling
- leakage
- staining
- window defect
Pooling on FA indicates a breakdown of?
outer blood retinal barrier
* abnormal choroidal neovasc is leaky and dye will escape, accumulation of fl into distinct space
What supplies the outer one-third of the retina?
The choriocapillaris
The choriocapillaris is fenestrated, allowing fluorescein to readily diffuse through these vessels.
What is the primary blood supply for the inner two-thirds of the retina?
Central retinal artery
*supplies inner retina
These vessels possess tight endothelial junctions, forming the inner blood-retinal barrier.
What should not allow for leakage of fluorescein in a normal retina?
The inner blood-retinal barrier
This barrier is formed by tight endothelial junctions of retinal blood vessels.
What happens to endothelial junctions in diabetes cases?
They become destroyed
This leads to leakage of fluorescein from retinal vessels.
What effect do dot/blot hemorrhages have on fluorescence?
They block fluorescence locally
This is due to leakage of the retinal vasculature.
What appears as areas of hypofluorescence?
Capillary nonperfusion
This indicates regions where blood flow has been compromised.
What do leaky vessels appear as in fluorescein angiography?
Hyperfluorescent
This indicates excessive leakage of fluorescein from the vessels.
What are microaneurysms and areas of retinal edema characterized by in fluorescein angiography?
Hyperfluorescence
This suggests increased permeability or leakage in these areas.
What appearance do cotton wool spots have in fluorescein angiography?
Hypofluorescent
This indicates areas of localized ischemia or blockage in the retina.
What do areas of neovascularization appear as in fluorescein angiography?
Hyperfluorescent
This shows the presence of new, abnormal blood vessel growth.
Normal ESR for men
- age/2
Example: Male age 30
30/2 = 15 mm/hour
Male age 50
50/2 = 25 mm/hour
Under 50 years old = ESR 0-15 mm/hour
Over 59 years old = ESR 0-20 mm/hour
Normal ESR for women
(Age + 10)/ 2
Under 50 = ESR 0-20 mm/hour
Over 50 = ESR 0-30 mm/hour
What is edrophonium commonly used for?
Diagnosis of myasthenia gravis
Edrophonium is also known by its trade names Tensilon and Enlon.
What type of agent is edrophonium?
Anticholinesterase agent
*diagnostic testing for myasthenia gravis
How does edrophonium work?
Inactivates the acetylcholinesterase enzyme, allowing accumulation of acetylcholine (ACh) in the neuromuscular junction
What is the onset time for edrophonium?
30-60 seconds
What is the duration of action for edrophonium?
10 minutes
How is edrophonium administered?
Injected intravenously
What are the risks associated with edrophonium in certain patients?
Can be very dangerous in patients with cardiac or respiratory diseases
What is another important diagnostic test for myasthenia gravis?
Evaluation of electromyographic responses to nerve stimulation at the neuromuscular junction
What do electromyographic measurements commonly reveal in myasthenia gravis?
Single-fiber atrophy
What will serum testing in myasthenia gravis patients reveal?
Significant levels of circulating antibodies to acetylcholine receptors
What is the positive ice-pack test used for?
To aid in the diagnosis of myasthenia gravis
What does improvement in eyelid position after ice application indicate?
Improved neuromuscular transmission at lower temperatures
What diagnostic testing should be performed for patients with unilateral myasthenia symptoms?
MRI or CT of the brain
What does an amelanotic choroidal melanoma look on B-scan?
Dome/mushroom shaped tumor
Choroidal excavation
Orbital shadowing
Attenuation of signals
Steep angle kappa
What would familial drusen look like on OCT Mac?
Thickening of RPE-bruch’s membrane complex with intact photoreceptors layer
- familial drusen smaller, more numerous and evenly distributed throughout the posterior pole
- monitor for progression, give at home Amsler
ERG and dark adaptation test rests for familial drusen
Normal ERG and normal dark adaptation test
Diagnostic testing for patient taking plaquenil long term
- OCT Mac
- mfERG
- FAF
- 10-2 VF
Also need:
Check color vision
Daily amsler grid
Baseline testing within 1st year of drug initiation
Testing after 5 years of therapy unless high risk
If high risk (elderly, kidney/liver disease, increased BMI)
Most see pts on an annual basis
True or false
A red-free filter will cause a lesion in the RPE to be darker and more defined
TRUE
* while choroidal pigmentation will be harder to see/invisible
True or false ERG is normal in RP
FALSE
ERG is abnormal in RP
Is ERG and EOG normal and/or abnormal in Best disease?
Normal ERG
Abnormal EOG
Is ERG and EOG normal and/or abnormal in Stargardt?
Normal ERG
Normal EOG
Is ERG and EOG normal and/or abnormal in choroideremia?
Abnormal ERG
Abnormal EOG
Which imaging technique is best to evaluate polypoidal choroidal vasculopathy?
Indocyanine Green angiography
*highlight choroidal vasculature
(+) FTA-ABS and (-) VDRL or (-) RPR means?
History of syphilis infection, but no current/active infection
What blood works needs to be positive in order to confirm active infection of syphilis?
(+) FTA-ABS and (+) VDRL [or (+) RPR]
What is MRD measuring?
Marginal reflex distance (distance between upper eyelid margin and corneal light reflex)
MRD1 Normal is 4.5 mm
MRD 2 normal is 5mm
MRD1 + MRD 2 = PF
PF: palpebral fissure
Normal ~10mm
