Download S. Aguilar

Retrobulbar spot sign: Ultrasonic evidence of embolic central retinal artery
occlusion in a patient with clinical features of temporal arteritis
Stephanie M. Aguilar, O.D.
A patient presents with sudden painless vision loss from central retinal artery occlusion and
clinical features suggestive of temporal arteritis. B scan findings point to embolic disease. The
determination of etiology and management are discussed.
I.
Case history
 Patient demographics: 72 year old white male of Irish and French descent
 Chief complaint: Patient reports constant, dark vision OS that began 15 days
prior upon awakening in the morning. He reports that when he looks directly at
a light he can see some light but the center is completely black. It has not gotten
worse or better since symptoms first started. No flashes of light noted. He
reports a dull ache around his left eye. No numbness or tingling sensations in
extremities. No jaw claudication, scalp tenderness, or temple pain.
 Ocular history: left homonymous hemianopsia OU, cataract OD, pseudophakia
OS, dry eye syndrome OU, refractive error and presbyopia
 Medical history: DM type II, hypertension, hyperlipidemia, obesity, right occipital
CVA in 2005, anemia, gastrointestinal stromal tumor in remission, congestive
heart failure, cardiomyopathy, obstructive sleep apnea, smoking cessation in
2008
 Medications: Aspirin 81mg, Multivitamin, Allopurinol 300mg, Carvedilol 25mg,
Glucose 4gm, Lisinopril 5mg, Torsemide 20mg, Rosuvastatin CA 20mg, Insulin
100unit/ml, Colchicine 0.6mg
 Salient information: Torsemide 20mg and Carvedilol 25mg dosed at 11:00pm
II.
Pertinent findings
 Clinical findings
 Visual acuity:
OD 20/25-2 PH 20/25+2
OS: light perception with projection
 CVF: OD constricted nasal, OS HM in all quadrants except NLP temporal
 Pupils: RRL 4+APD OS
 IOP: OD 20 mmHg, OS 14 mmHg
 Macula: OD clear, OS cherry red spot


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 Vessels: OD clear, OS attenuated arteries
 Posterior pole: OD clear, OS superficial whitening of retina with apparent
edema
 Optic nerve: OD 0.55 C/D, OS pale nerve 360 with visible plaque in central
retinal artery (photographic evidence reveals plaque was known to be
present in November 2012)
 No NVI/NVA/NVD/NVE upon 4 week follow up
Physical findings
 Temporal arteries: non-tender R/L, pulsatile on right only
Laboratory findings
 ESR: 74
 CRP: 8.54
 Platelets: 194
 eGFR: 18
 Creatinine: 3.34
 Glucose: 120 mg/dL
 Triglyceride: 674 mg/dL
Radiology studies
 Carotid Doppler: >90% stenosis of left internal carotid artery
 B scan: two hyper-reflecting areas that may correspond to two plaques in
central retinal artery OS
 CT head: no acute process
 SD-OCT: edematous inner retinal layers OS
III.
Differential Diagnoses
 Primary: embolic central retinal artery occlusion
 Secondary: central retinal artery occlusion due to temporal arteritis
IV.
Diagnosis and discussion
The diagnosis is embolic central retinal artery occlusion (CRAO) of the left eye occurring at the
beginning of July 2015, two weeks prior to patient presenting to clinic. Given the ultrasound
result of greater than 90 percent stenosis of the internal carotid ipsilateral to the symptomatic
eye and the absence of systemic symptoms suggestive of giant cell arteritis a diagnosis of
embolic central retinal artery occlusion is primary. Follow up of the ESR demonstrated a
declining value consistent with non- arteritic stenosis. His risk factors for temporal arteritis
include his increased age and race. The ocular pain in the left eye was reportedly present for
only thirty minutes and subsided indefinitely.
The carotid duplex showed greater than 90 percent stenosis of the left internal carotid artery.
Interestingly, in November 2012, a calcific embolus in the left central retinal artery was noted
which led to a subclinical branch retinal artery occlusion in the inferior nasal quadrant. B scan
ultrasonography showed two hyper-reflective plaques, likely the second more proximal plaque
is located where the central retinal artery pierces the dural sheath of the optic nerve, causing
the occlusive event. This is known as the “spot sign”. 1 Thus, the CRAO is likely due to a second
deep embolus at the lamina cribosa in combination with reduced arterial pressure and severe
ipsilateral internal carotid artery stenosis contributing to the perfusion failure. It is worthwhile
to note that the patient first became aware of vision loss upon awakening and is dosing antihypertensive medication, Carvedilol and Terosemide, at 11:00pm. It is possible that this dosing
pattern exacerbated physiological nocturnal hypotension and in the setting of carotid disease,
reduced retinal perfusion to such a degree that infarct resulted.
This patient’s functional impairment attributable to the artery occlusion is made worse by the
history of right occipital lobe vascular accident in 2005 resulting in a left homonymous
hemianopsia. Thus making long-term management of this case more complicated and
atherosclerotic risk factor management all the more significant. After the most recent occlusive
event of the central retinal artery, the patient has only one-fourth or approximately 90 degrees
of his bilateral visual field intact, leaving his visual field severely constricted and his stereopsis
nonexistent.
V.
Treatment and management
Acute management of CRAO begins with an attempt to recover vision. It has been shown in an
experimental study of CRAO in rhesus monkeys that complete ischemia to the retina of more
than four hours resulted in severe irreversible neuronal loss. 2 The conservative method of
treatment for CRAO includes ocular massage, hyperbaric oxygen, anterior chamber
paracentesis, corticosteroids and topical anti-hypertensive medications among others.
Although, none have proven to be more effective than a placebo and may actually be harmful.3
The exception is CRAO due to temporal arteritis, where prompt systemic steroid therapy can
improve the visual prognosis. 4 Thrombolysis is currently the most popular therapy, and success
has been enthusiastically claimed. However, intra-arterial thrombolytic therapy has only been
proven beneficial for treatment of fibrin emboli and within four hours of onset.5
Long term management of CRAO focuses on preventing recurrent vascular events.
Management is cause specific; high grade carotid disease should undergo carotid
endarterectomy while a cardiac source of emboli should be managed with anti-coagulation
medication. 6 This population is at high risk of secondary or tertiary ischemic events, so risk
factor modification is prudent. 7 In all geriatric cases, atherosclerosis risk factor modification
should be employed.
In this particular case, the patient underwent a left carotid endarterectomy. He will be
scheduled for mobility training and rehabilitation in the low vision clinic. One month follow up
revealed no neovascularization and similar visual acuity to that at first presentation. Comanagement with the patient’s cardiologist and primary care physician are employed to
hopefully increase the patient’s life span and quality of life.
Bibliography
1. Nedelmann M, Graef M, Weinand F, Wassill KH, Kaps M. Retrobulbar spot sign predicts
thrombolytic treatment effects and etiology in central retinal artery occlusion. Stroke. 2015
Aug;46(8):2322-4. Epub 2015 Jun 25.
2. Hayreh SS, Zimmerman MB, Kimura A, Sanon A. Central retinal artery occlusion. Retinal
survival time. Exp Eye Res 2004; 78: 723-736.
3. Schrag M, Youn T, Schindler J, Kirshner H, Greer D. Intravenous Fibrinolytic Therapy in
Central Retinal Artery Occlusion, A patient level meta- analysis. JAMA Neurol. Published online
August 10, 2015. jamaneurol.2015.1578.
4. Azhar SS, Tang RA, Dorotheo EU. Giant cell arteritis: diagnosing and treating inflammatory
disease in older adults. Geriatrics. 2005 Aug;60(8):26-30.
5. Hayreh SS. Intra-arterial thrombolysis for central retinal artery occlusion. Br J Ophthalmol
2008 92: 585-587.
6. Kramer M, Goldenberg-Cohen N, Shapira Y, Axer-Siegel R, Shmuely H, Adler Y. Role of
transesophageal echocardiography in the evaluation of patients with retinal artery occlusion.
Ophthalmology. Volume 108, Issue 8, August 2001, 1461-1464.
7. Varma DD, Cugati S, Lee AW, Chen CS. A review of central retinal artery occlusion: clinical
presentation and management. Eye 2013. Published online: 8 March 2013.
VI.
Conclusion
This case elaborates on how atherosclerotic disease and consequently, stroke can change a person’s life,
render them legally blind and alter their daily functionality. It is possible the CRAO event may have
saved this patient’s life because without it, the high grade carotid artery stenosis may not have been
discovered until too late. In this ophthalmic emergency, prompt consultation with the neurology
department was key . B scan ultrasonography was supportive of our diagnosis and management. As
optometrists, it is our goal to use every tool available to conserve what is left of our patient’s vision and
visual field and thus enable them to live a full life.