B14-1 Artery Occlusions & Ischemic Disease Flashcards
What causes Ocular Ischemic Syndrome (OIS)?
Ipsilateral carotid obstruction or ophthalmic artery obstruction
Name 3 symptoms of Ocular Ischemic Syndrome (OIS)
- Gradual vision loss that develops over a period of weeks to months
- Aching pain localized to the orbital area of the affected eye
- Prolonged vision recovery after exposure to bright light
Name 2 anterior segment findings associated with Ocular Ischemic Syndrome (OIS)
- NVI in 2/3 of cases
- Anterior chamer cellular response in 1/5 of eyes
Several vascular diseases can cause NVI/NVA, what is one scenario that is characteristic of Ocular Ischemic Syndrome (OIS)?
NVA & low IOP, doesn’t usually happen, most likely due to imparied aqueous production
Ocular ischemic syndrome can cause a retinopathy similar in appearance to a partial CRVO &/or Diabetic Retinopathy; what is one differentiator found on a fundus exam that is characteristic of OIS?
Mid-peripheral dot/blot hemorrhages, whereas Diabetes primarily effects the posterior pole only
Name a test that can be helpful in differentiation of Ocular Ischemic Sydrome from a CRVO/CRAO?
ERG:
- demonstrates global amplitude reduction in OIS
- an electronegative electroretinogram occurs in the case of a CRVO/CRAO since they largely affect only the inner-retinal structures, whereas OIS compromises the entire eye
Most common etiology of OIS? What are some other causes?
- Atherosclerosis
- Carotid artery dissection or Giant Cell/Temporal arteritis
How much obstruction is necessary to cause OIS?
90%
What is the 5-year mortality rate of patients with OIS?
40%
What is the most definitive Tx for OIS?
- Carotid artery stents
- Endarterectomy
Name 3 studies that should be performed with OIS
- Carotid duplex
- CTA/MRA of head and neck
- Consult with cardiology and/or vascular surgery
What is the perioperative risk of death in a symptomatic OIS patient?
< 6%
What is the perioperative risk of death in an asymptomatic OIS patient?
< 3%
What is the most common type of emboli involved with an ocular artery occlusion? Describe it
Hollenhorst plaque, which is refractile yellow-white cholestrol from the carotid
Urgent specialist vascular evaluation is rapidy becoming the standard of care following a retinal arterial event. Why?
Because 25% of TIA patients will have a stroke within 3 years
What percentage of CRAO cases are caused by GCA? What age do these usually occur?
1-2%, extremely unlikely under the age of 55
Other than regular cardiac evaluation like BP, pulse, auscultation, etc., what systemic assessments do all artery occlusion patients typically have?
MRA/CTA for neuro assesment
ECG for arrhythmia and/or other cardiac disease
ESR/CRP for GCA
Carotid Duplex to check severety of stenosis
Other blood tests like CBC, glucose, lipids, urea and electrolytes
Characterized by a transient, painless, monocular loss of vision that is often described as a “curtain coming down over the eye”
Amaurosis Fugax
Overall, how should you treat any artery occlusion, whether it be a TMVL/CRAO/BRAO? What were the numbers from the meta analysis to support this?
As an acute stroke, because roughly 20-30% of BRAO/CRAO patients and 8-11% of TMVL patients are having/will have a stroke
What is the most common cause of Cotton-Wool Spots (CWS)? How do they form? What’s the usual course of action upon finding a CWS?
- Diabetic Retinopathy
- acute obstruction in the distribution of the radial peripapillary capillary net, NOT an artery or arteriole
- not typicallly an urgent or emergent scenario, can usually be monitored and evaluated on an outpatient basis and they will typically fade in 5-7 weeeks.
- HOWEVER, even 1 CWS in an otherwise apparently healthy eye should prompt the clinician to initiate a workup for underlying etiology
What is the typical course of a BRAO?
- sudden and painess unilateral visual field defect and/or reduction in VA (patient may complain of “blacking out”, flickering, or dimming of their vision)
- an acute BRAO may be subtle and unapparent on initial fundus exam, but then can lead to edematous opacification within hours to days
- in time, the occluded vessel recanalyzes, perfusion returns, and the edema resolves. HOWEVER, a permanent visual field defect remains.
How is a BRAO confirmed?
Visual Field Defect, since it is usually permanent
What are the 3 main varieties of emboli that form Branch Retinal Artery Occlusions (BRAO)
- Cholestrol emboli - Hollenhorst plaques (from carotid arteries)
- Platelet-fibrin emboli (from large-vessel arteriosclerosis)
- Calcific emoli (from cardiac valves)
Patient presents completely assymptomatic (ocularly and systemically) but you find what appears to be a Hollenhorst Plaque on the fundus exam. What do you do?
- Do NOT assume it is a BRAO, but DO assume that it is new
- Obtain records and order or recommend fairly urgent studies/evaluations (like a bilateral carotid duplex)
- If the plaque has been present for some determined amount of time (many months/years), make sure they are following up with their other Doctor’s recommendations
