MARCH 23 , 2012LORI NOOROLLAH

Neurology Case Presentation

Chief Complaint

Double Vision

HPI: Middle aged woman who reports that she woke up

with blurry vision and pain in her right eye Two week later– woke up with double vision

Binocular, vertical and horizontal Worse on right gaze

Three months later– woke up with blurry vision in left eye and left orbital pain

PMH: HTN, Anxiety, chronic pain, GI bleed due to

diverticulosisMeds:

Clonidine 0.2mg qHS Metoprolol 50mg BID Diazepam prn Diltiazem qAM Losartan 100mg qHS hydrocodone prn

SH: Smokes 3-4 cigarettes daily for 25 years No EtOH or illicit drug use

More History

General Exam

Alert, oriented, no acute distressCV: RRR, no carotid bruitChest: CTABVisual Acuity:

OD: 20/60 OS: 20/25

+relative APD on right red-green dyschromatopsia on right

Neurological Exam

Mental status and speech normalCN:

PERRL APD on right Visual Fields –

Inferior arcuate defect on Right Enlarged blind spot on Left

normal facial sensation and movement, symmetric palate elevation, tongue midline

EOM:Limited abduction and slightly limited upgaze bilaterally

Motor, Sensory, Reflexes, Coordination – within normal limits

Visual Fields

Inferior arcuate defect in right eye Enlarged blind spot in left eye

?Where?

?What?

Differential Diagnosis

Anterior Ischemic Optic Neuropathy (AION) + cranial nerve infarcts AAION vs. NAION

Optic NeuritisOcular Myasthenia gravis

Acetylcholine receptor antibodies negative

NAION

Non-arteritic Anterior Ischemic Optic Neuropathy is an

“idiopathic” ischemic insult of the optic nerve head

Most common optic neuropathy Annual incidence for people > age 50 is 2.3 – 10.2

/100,000 95% of cases occur in Caucasian population

NAION

Clinical presentation: Sudden monocular visual loss Blurring or cloudiness Often noticed upon awakening (73%) Most often painless

12% have ocular pain or headache A lot of pain more suggestive of optic neuritis

or AION Exam:

Reduced visual acuity to varying degrees Not ruled out by normal visual acuity

Dyschromatopsia proportional to reduction in visual acuity Afferent pupillary defect Fundoscopic Exam:

Optic disc swelling Disc hyperemia with splinter or flame hemorrhages Small optic cup (nerve fiber crowding) in unaffected eye

Visual field defect – relative inferior altitudinal defect and absolute inferior nasal defect

Hayreh SS (2009) Ischemic optic neuropathy. Progress in retinal and eye research 28: 34-62

NAION – Fundoscopic Exam

NAION

Vascular supply to optic nerve head 15-20 short posterior ciliary arteries, supplied by ophthalmic artery

NAION

Pathogenesis: Different than Ischemic CVA

No clear relationship with HTN, HLD, smoking Not associated with embolism or large vessel occlusion

Transient hypoperfusion of posterior ciliary arteries Vasospasm vs. nocturnal hypotension vs. impaired

autoregulation of microvasculature vs. vasculopathic occlusion vs. venous insufficiency

Hypoxia/Ischemia optic disc swelling (in setting of physiologically crowded optic nerve head) infarction

Treatment = Modify risk factors, vision therapy Early therapy shown to have better recovery Questionable role for steroids

NAION and OSA

Nocturnal Hypotension Normal physiologic occurrence Autoregulation

OSA Loss of autoregulation Non-dipping status Hypoxic-ischemic insult to optic nerve head

Anti-hypertensive medications at night may also disrupt autoregulation

OSA and NAION

Stein, 2011 – American Journal of Ophthalmology

Retrospective cohort study Review from managed care database looking at

patients > 40 with at least 1 eye-care visit N=2,259,061 Compared incidence of NAION in population with and

without OSA Compared NAION in treated vs. untreated OSA

OSA and NAION

Results:After adjusting for confouding variables:

Untreated OSA patients had 16% increased hazard of experiencing NAION (HR 1.16, CI 1.01-1.33) compared with non-OSA patietns

Treated OSA patients had no difference in hazard (HR 1.38, CI 0.76-2.5) compared with non-OSA patients

NAION – Future Studies

Implications: Do patients with NAION need screening for OSA? Do patients with OSA need evaluation? Consider avoiding anti-hypertensive medications at

night, especially in patients “at risk” for NAION

Future Studies: Treatment options/Intervention/Prevention Further investigation into the pathophysiology of

NAION

References

Anterior Ischemic Optic Neuropathy:Part II: a discussion for physicians. Sohan Singh Hayreh, MD, MS, PhD, DSc, FRCS, FRCOphthhttp://webeye.ophth.uiowa.edu/component/content/article/118-aion-part2

Atkins, EJ Nonarteritic Anterior Ischemic Optic Neuropathy. Current Treatment Options in Neurology. 2011; 13: 92-100

Hayreh SS (2009) Ischemic optic neuropathy. Progress in retinal and eye research 28: 34-62

Kerr NM, Etal. Non-arteritic ischaemic optic neuropathy: A review and update. Journal of Clinical Neuroscience. 2009; 16: 994-1000.

Stein JD, Etal. The Association between Glaucomatous and other causes of Optic Neuropathy and Sleep Apnea. Am J Ophthalmol. 2011; 152: 989-998.

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