Download A case of bilateral asymmetric anterior ischemic optic neuropathy is

Catherine Chiu
An asymptomatic patient presents with a superior altitudinal defect OD and an inferior
altitudinal defect OS. A discussion of AION vs. NAION will clarify pertinent clinical
findings to apply to patient care.
I. Case History:
83 year old white male presents for an ocular health exam with no visual complaints and
admits to a history of constriction of retinal blood vessels three years ago.
A. Ocular history: unremarkable except for floaters which are stable
B. Medical history: (+) hypertension with heart involvement, atherosclerosis,
hypercholesterolemia, hypothyroid, coagulation defect, prostate cancer
C. Medications: levothyroxine, metropolol, niacin, simvastatin
II. Pertinent Findings:
A. Clinical: BCVA OD: 20/20-, OS: 20/20-2
Pupils: PERRL (-) APD
CVF: OD FTFC, OS FTFC
EOM: Full and smooth OU
SLE: unremarkable expect for Nuclear sclerosis OU
IOP: OD 19mmHg, OS 20 mmHg
DFE: Vitreous – Clear OD, OS
Disc – OD 0.55, OS 0.45 with rim pallor OU
Macula – Clear OD, OS
Vessels: Attenuation of arterioles OD, OS
Periphery: Drusen OD, OS
24-2 Visual Field: OD Superior altitudinal defect
OS Inferior altitudinal defect
Pachymetry: OD 535, OS 537
B. Radiology:
CT-Scan: Normal pressure hydrocephalus (NPH)
C. Neurology: No abnormal findings, NPH ruled out because patient did not
present with the triad of ataxia, dementia and incontinence, repeat of CT-Scan
required
III. Differential Diagnosis:
1. Non-arteritic anterior ischemic optic neuropathy (NAION)
2. Arteritic anterior ischemic optic neuropathy (AAION)
IV. Diagnosis and Discussion:
-VF findings, DFE, and a good VA strongly suggests pt had an ischemic incident causing
AION
-AAION:
- sudden visual loss, altitudinal visual field loss, afferent papillary defect (APD),
optic disc edema
- any vasculitis, such as giant cell arteritis (GCA)
- arteritic occlusion of the posterior short ciliary arteries
- results in nearly complete loss of vision
- occurs in older adults
- symptoms include painful jaw muscle spasms, scalp tenderness, unintentional
weight loss, fatigue, myalgias and loss of appetite
- contralateral eye involvement within 1-2 weeks after first eye event
- blood tests reveal elevated erythrocyte sedimentation rate (ESR), C reactive
protein (CRP) and platelet count (thrombocytosis)
-NAION:
- occlusion of ciliary arteries by thrombi or emboli causing temporary
hypoperfusion of the anterior portions of the optic nerve and choroid
- contralateral eye involvement months to years after first eye event
- cardiovascular conditions such as arterial hypertension, diabetes and
atherosclerosis
- crowded disc or small physiologic cupping
- painless symptoms
- can occur in young and older adults
V. Treatment:
- Work up with PCP to control hypertension and other cardiovascular risk factors
- Follow up with neurologist with additional CT-Scan findings
- Educated patient to be aware of any vision changes or vision loss
- Monitored through periodic visual field exams
VI. Conclusion:
- patient admitted to nasal blur of vision in the right eye followed by nasal blur of vision
in the left eye a day later three years ago, but never had a decrease of VA since the
incident
- patient most likely had NAION due to medical history of hypertension, atherosclerosis,
and hypercholesterolemia