Leo P. Semes
A 63-year-old man with a 15-year history of type 2 diabetes came in for
new glasses stating his right eye had not seen well for several months. There
was no history of pain or flashes or floaters.
His medical history included diabetes, chest pain, mitral valve
disorder, cerebrovascular disease, prior myocardial infarction, hyperlipidemia,
hypertension and general osteoarthrosis.
The patients current medications were: amlodipine 10 mg daily,
hydrochlorothiazide 12 mg daily, metoprolol tartrate 50 mg twice daily for high
blood pressure, nitroglycerin 0.4 mg as needed and nitroglycerin patch 10 mg/24
h for heart disease, warfarin 2 mg at bedtime for blood clots, metformin 500 mg
once daily for diabetes, simvastatin 40 mg tablet once daily for cholesterol,
multivitamin/mineral supplement daily and acetaminophen 325 mg as needed for
Images: Bockin DG
His visual acuity was 20/200 OD and could not be improved with pinhole
or refraction. With 3.50 D sphere before the left eye, visual acuity was
20/20. Versions were smooth and full, and confrontation visual fields were full
in the left eye with overall constriction in the right. Pupils were unequal (5
mm OD and 3 mm OS), round and reactive to light with a moderate relative
afferent pupillary defect in the right eye.
No hemorrhages or exudates were seen in either eye.
The patients IOP was 12 mm Hg OD and 13 mm Hg OS. Examination of
the anterior segment was unremarkable except for mild nuclear sclerosis in both
A visual field was ordered.
Fundus examination revealed a pale optic disc and attenuated blood
vessels in the right eye. The left eye was unremarkable. There were no
hemorrhages or exudates in either eye.
What is your diagnosis?
Possible diagnoses include diabetic retinopathy, arteritic ischemic
optic neuropathy, central retinal vein occlusion and central retinal artery
Arteritic ischemic optic neuropathy (AION) occurs in patients older than
50 with acute severe vision loss. There usually is a history of temporal
headache with scalp tenderness, jaw claudication, muscle pains, weakness,
weight loss, a significant afferent pupillary defect, pale optic disc swelling
and markedly increased erythrocyte sedimentation rate (ESR).
AION is attributed to ischemia at the optic nerve head due to structural
crowding that may impair perfusion to the nerve and thereby cause edema. The
condition is divided into two subcategories: nonarteritic (NAION) and arteritic
(AAION). The latter is most commonly associated with temporal arteritis.
The patient demographic for AION is typically older than age 50; the
median age group for NAION is older than 60, and with AAION the median age is
70 years. There is a gender predilection for females, but only in cases of
AAION. Incidence of AAION is 5% to 10% of cases, while NAION accounts for 90%
to 95% of AION cases.
A tiny amount of hard plaque was seen in the
posterior wall of the carotid bulb and perhaps also at the origin of the right
internal carotid artery. However, normal Doppler tracings were obtained in the
right common carotid artery, carotid bulb and its internal and external
branches. A small amount of hard plaque was also seen in the left carotid bulb
and the origins of the left internal and external carotid arteries. Normal
Doppler tracings were obtained in the left common carotid artery and carotid
bulb. Mild turbulence was seen in the left internal and external carotid
arteries, but no velocity shift was measured. Normal antegrade flow was seen in
both vertebral arteries. A small amount of hard plaque was seen in the left
carotid bulb and its internal and external branches. Only a minimal amount of
hard plaque was seen in the right carotid bulb. No significant stenosis was
seen by Doppler measurement.
Patients with either form of AION typically report a rapid onset of
painless, unilateral visual loss manifested by decreased visual acuity, visual
field or both. Vision loss is more severe in AAION, typically less than
The most common visual field defect with either form of AION is
altitudinal, but it may also present as a general depression, an arcuate
scotoma or a cecocentral defect. A retrospective study using Goldmann perimetry
suggested that the most common field loss was actually inferior nasal and, when
combined with overall inferior field loss, it is highly indicative of NAION.
The inferior nasal defect is explained by the location of the watershed zone of
the posterior ciliary arteries, which is often temporal to the optic nerve head
and the most susceptible to ischemia.
Signs of an AION are a pale and hyperemic optic nerve head with edema
(diffuse or segmental) in the acute phase and optic atrophy in later stages.
The edema may be present several weeks to months before vision loss is
reported. One source suggests that in AAION the disc is more pallid than
hyperemic, which is more common with NAION. Flame hemorrhages and narrowed
peripapillary arterioles are other signs associated with AION. Also, because
the presentation is typically unilateral, a relative afferent pupillary defect
is often expected. Systemic associations with the arteritic form are symptoms
common with temporal arteritis (i.e., headache, jaw claudication and scalp
tenderness). Vision loss in the arteritic form may be preceded by episodes of
transient vision loss, which is also highly indicative of arteritis.
Central retinal artery occlusion (CRAO) is a unilateral, painless, acute
vision loss that occurs over several seconds. There may be a history of
amaurosis fugax, which did not present in this case. There is a marked afferent
pupillary defect, narrowing retinal arterioles, box-carring or segmentation of
the blood column in the arterioles. Occasionally, retinal emboli or
cilioretinal artery sparing of the foveola is evident.
The etiology is an embolus more often from the carotid arties, but
possibly cardiac in origin.
Sudden onset of CRAO may be treated using heroic measures with immediate
ocular digital massage, anterior chamber paracentesis, acetazolamide 500 mg IV
or two 250-mg tablets or a topical beta blocker. All treatment is aimed at
reducing intraocular pressure to help restore blood flow.
The diagnosis of CRAO was based on the carotid studies, in that the
patient had an abnormal result. In addition, no retinal hemorrhages were
present, which, in CRVO, may be present for several months after the
The patient was referred to his primary care physician for re-evaluation
of bloodwork and a carotid Doppler ultrasound.
On follow-up examination the patients vision was stable. His
primary care doctor changed no medications but will administer more frequent
physical evaluations. Discussion with the patients primary care physician
for a referral for a carotid endarterectomy was considered, but the patient was
in poor health and may not survive the surgery.
- Arnold AC. Ischemic optic neuropathies. Yanoff & Duker
- Ehlers JP, Chirag PS. The Wills Eye Manual, 5th ed.
2008. Baltimore, MD: Lippincott Williams & Wilkins.
- Hayreh SS, Zimmerman B. Visual field abnormalities in nonarteritic
anterior ischemic optic neuropathy: Their pattern and prevalence at initial
examination. Arch Ophthalmol. 2005;123:1554-1562.
- Donald G. Bockin, OD, can be reached at 1174 Windy Hill, Salado, TX
- Edited by Leo P. Semes, OD, a professor of optometry, University of
Alabama at Birmingham and a member of the Primary Care Optometry
News Editorial Board. He may be contacted at 1716 University Blvd.,
Birmingham, AL 35294-0010; (205) 934-6773; fax: (205) 934-6758;