MARCH 23, 2012 LORI 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 diverticulosis Meds:  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 distress CV: RRR, no carotid bruit Chest: CTAB Visual Acuity:  OD: 20/60  OS: 20/25 +relative APD on right red-green dyschromatopsia on right

Neurological Exam Mental status and speech normal CN:  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 eyeEnlarged blind spot in left eye

?Where? ?What?

Differential Diagnosis Anterior Ischemic Optic Neuropathy (AION) + cranial nerve infarcts  AAION vs. NAION Optic Neuritis Ocular 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: NAION – Fundoscopic Exam

NAION Vascular supply to optic nerve head  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 ) compared with non-OSA patietns  Treated OSA patients had no difference in hazard (HR 1.38, CI ) 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, FRCOphth Atkins, EJ Nonarteritic Anterior Ischemic Optic Neuropathy. Current Treatment Options in Neurology. 2011; 13: Hayreh SS (2009) Ischemic optic neuropathy. Progress in retinal and eye research 28: Kerr NM, Etal. Non-arteritic ischaemic optic neuropathy: A review and update. Journal of Clinical Neuroscience. 2009; 16: Stein JD, Etal. The Association between Glaucomatous and other causes of Optic Neuropathy and Sleep Apnea. Am J Ophthalmol. 2011; 152: Up To Date Online