Anterior ischemic optic neuropathy after emergency caesarean section under epidural anesthesia

Acta Anaesthesiol Scand 2002; 46: 751–752 Copyright C Acta Anaesthesiol Scand 2002Printed in Denmark. All rights reserved

ACTA ANAESTHESIOLOGICA SCANDINAVICA

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Case Report

Anterior ischemic optic neuropathy after emergencycaesarean section under epidural anesthesia

M. GUPTA, P. PURI and I. G. RENNIE

Department of Ophthalmology, Royal Hallamshire Hospital, Sheffield, England

We report a case of non arteritic anterior ischemic optic neuro-pathy following caesarean delivery in a patient who had epi-dural analgesia. There was doubt as to whether it was subdural.The patient underwent caesarean section because of secondstage non-progression of labor. We discuss the possible etiologyof this unpleasant complication.

ANTERIOR ischemic optic neuropathy is a sightthreatening condition. Cranial nerve palsies

after epidural and spinal analgesia are reported. Wereport a case of anterior ischemic optic neuropathyafter caesarean section under epidural analgesia.

Case report

A 28-year-old female (gravida 1, para 0) presented tothe eye casualty with a 10-day history of vision dimin-ution in the right eye, which started the day after acaesarean section. She underwent an emergency caes-arean section because of non-progression of secondstage of labour, which was performed under epiduralanesthesia. A possible accidental dural puncture wasrecorded during the epidural but the patient was stillmanaged as an epidural and not as a spinal. On ad-ministration of 6 mg ephedrine, the patient sufferedan 3–4 min acute hypotensive episode wherein herblood pressure dropped to 62/50 mmHg, which wasthen slowly built back up to 120/64. Further top upswere made with marcain 0.5%. The patient had noother problems with her general health. Her bloodpressure stayed normal during delivery and her pre-delivery blood pressure was 103/60. The caesareansection was uneventful with an estimated blood lossof approximately 500 ml. The baby was healthy withno evidence of any neurologic damage.

A neurologist saw her in the intervening period andnoted bilateral swollen optic discs. A provisional di-

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Received 30 September 2001, accepted for publication 10 January 2002

Key words: epidural anesthesia; anterior ischemic optic neuro-pathy; emergency caesarean section.

c Acta Anaesthesiologica Scandinavica 46 (2002)

agnosis of bilateral papilledema was made, and shewas investigated to rule out thrombotic loss of vision,sagital sinus thrombosis and benign intracranial hy-pertension.

Her full blood count, urea and electrolytes, randomblood sugar, liver function tests, serum immunoglob-ulins, serum antibodies, and thrombophilia screenand computerized tomography scans of the head andorbits were all normal. A magnetic resonance imagingof the head and orbits and a magnetic resonance an-giography to look for any abnormality of the intra-cranial blood vessels was also performed, and re-ported as normal. Lumbar puncture was also normal.

On presentation to ophthalmology, she had a best-corrected visual acuity of 6/36 and 6/5 in the rightand left eyes, respectively (normalΩ6/6). There was arelative afferent pupil defect on the right side. An-terior segment and intraocular pressure were normalin both eyes. The right optic disc was swollen, beingpale in the upper part and hyperemic in the lowerhalf. The margins of the left disc were also slightlyblurred. A fundus flourescein angiography was per-formed, which showed a swollen right optic disc withleakage of the dye. Left disc was normal. A B-scanocular ultrasound was performed to exclude an opticdisc drusen, but no drusen was seen in either eye.The patient was diagnosed with non arteritic anteriorischemic optic neuropathy (NAAION).

She was reviewed in the eye clinic 3 months laterwhen her best-corrected visual acuity was 6/18 in the

M. Gupta et al.

right and 6/5 in the left eye. The right optic discswelling was less with residual partial optic atrophy.She continued to maintain good general health otherthan occasional headaches. Her vision has notchanged in 7 months.

Discussion

Anterior ischemic optic neuropathy is a syndrome inwhich optic nerve head ischemia is presented as aswelling of the optic disc (1). It is more common inpatients older than 60 years and has no sex predis-position (2). It can be arteritic, more commonly knownas giant cell arteritis, which is a vasculitis of the pos-terior ciliary arteries, or non arteritic; the exact pathol-ogy of which remains unknown.

It is thought that NAAION is caused by a compro-mise in the optic nerve blood flow and resultant ische-mia (3). The most common presentation is a sudden,painless unilateral loss of vision less severe than inthe arteritic group. The visual acuity may or may notbe affected in this condition and if affected can im-prove partially (4).

It can be associated with conditions such as periodicnocturnal systemic hypotension (5), hypertension,diabetes, migraine, optic disc drusen, hyperlipidemia,and acute blood loss, but in most instances the patientis systemically well. Swelling of the optic nerve head,which may be focal, segmental or total with or with-out flame shaped hemorrhages close to the disc, ispresent. Examination of the other eye may show asmall optic disc with small or absent cupping (6).

There is no proven treatment for this condition. Op-tic nerve sheath decompression and hyperbaric oxy-gen (7) have been tried with conflicting results. Useof aspirin is also disputed. There are three possibleprecipitating factors for causing optic neuropathy inthis patient: a small optic (disc at risk), acute bloodloss during the caesarean section (500 ml) (8), and hy-potension during the epidural anesthesia (9). Eitherone or a combination of these could have resulted in

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ischemic optic neuropathy. Enlund et al. (10) have alsoobserved unexplained arterial hypotension with gen-eral anesthesia.

To the best of our knowledge, there is only one pre-viously reported case of a similar loss of vision (8),but in that case there was a definite history of severeblood loss from an ectopic pregnancy.

References1. Arnold AC. Anterior ischemic optic neuropathy. Semin

Ophthalmol 1995: 10: 221–233.2. Johnson LN, Arnold AC. Incidence of non arteritic and art-

eritic anterior ischemic optic neuropathy: population basedstudy in the state of Missouri and Los Angeles County, Cali-fornia. J Neuro Ophthalmol 1994: 14: 38–44.

3. Guyer DR, Miller NR, Auer CL, Fine SL. The risk of cerebro-vascular and cardiovascular disease in patients with anteriorischemic optic neuropathy. Arch Ophthalmol 1985: 103: 1136–1142.

4. Arnold AC, Hepler RS. Natural history of non arteritic an-terior ischemic optic neuropathy. J Neuroophthalmol 1994: 14:70–76.

5. Hayreh SS, Zimmerman BM, Podhajsky PA, Alward WLM.Nocturnal arterial hypotension and its role in optic nervehead and ocular ischemic disorders. Am J Ophthalmol 1994:117: 603–624.

6. Beck RW, Servais GE, Hayreh SS. Anterior ischemic opticneuropathy. IX. Cup to disc ratio and its role in patho-genesis. Ophthalmology 1987: 94: 1503–1508.

7. Arnold AC, Hepler RS, Lieber M, Alexander JM. Hyperbaricoxygen therapy for nonarteritic anterior ischemic opticneuropathy. Am J Ophthalmol 1996: 122: 535–541.

8. Chun DM, Levin DK. Ischemic optic neuropathy after hae-morrhage from a cornual ectopic gestation. Am J ObstetGynecol 1997: 177: 1550–1552.

9. Remigio D, Wertenbaker C. Post operative bilateral visualloss. Survey Ophthalmol 2000: 44: 426–432.

10. Enlund M, Mentell O, Kerkmanov L. Unintentional hypo-tension from lidocaine infiltration during orthognathicsurgery and general anaesthesia. Acta Anaesthesiol Scand2001: 45 (3): 294–297.

Address:M. GuptaDepartment of OphthalmologyRoyal Hallamshire HospitalGlossop RoadSheffield S10 2JFEngland