Year : 1992 | Volume
: 40 | Issue : 2 | Page : 66--69
Bilateral optic nerve infarction following acute systemic hypotension and anemia-A case report
KB Chopra, NH Banka, HB Chandalia
Department of Medicine, Ward 8, Grant Medical College and Sir J.J.Group of Hospitals, Byculla, Mumbai - 400 008, India
H B Chandalia
18, Kala Bhavan, 3, Mathew Road, Mumbai 400 004
Presented here are case reports of two patients who became completely blind in both eyes following acute systemic hypotension - in one following bouts of vomiting and in the other after repeated gastrointestinal bleeding. Both patients had severe degree of anemia. There were no other risk factors for vascular disease such as arteriosclerosis or vasculitis.
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Chopra K B, Banka N H, Chandalia H B. Bilateral optic nerve infarction following acute systemic hypotension and anemia-A case report.Indian J Ophthalmol 1992;40:66-69
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Chopra K B, Banka N H, Chandalia H B. Bilateral optic nerve infarction following acute systemic hypotension and anemia-A case report. Indian J Ophthalmol [serial online] 1992 [cited 2020 Jul 14 ];40:66-69
Available from: http://www.ijo.in/text.asp?1992/40/2/66/25398
Visual loss after hemorrhage remote from the visual pathways has been recognised since Hippocrates, with 300 cases reported by the mid-century. Additional cases have been added since then  In the majority, the optic nerve or, less often, the retina, appears to be the site of damage.
We report here two patients who presented with simultaneous onset of visual loss in both eyes following an episode of systemic hypotension. Both patients had severe anemia. A brief discussion as regards the mechanisms underlying this visual loss follows.
CASE-1 : A 45 year old tailor was admitted to the hospital because of simultaneous onset of visual loss in both eyes. He was well six days prior to admission when he developed vomiting. The vomiting persisted for 6 days without any other accompanying symptoms. One day prior to admission, in the afternoon he complained of reduced visual acuity in both eyes simultaneously. Over a span of ten hours lie had a rapid deterioration in his visual acuity wherein he became completely blind. His past medical history revealed that he was not diabetic or hypertensive; there was no use of tobacco, drug ingestion or alcohol intake. We could elicit no prior history of neurologic or visual symptoms or ocular disease.
On admission, his blood pressure was 90/60 mm Hg. He was extremely pale with marked clubbing. Both superficial temporal arteries had normal pulsations and were non-tender and smooth. Both eyes could not perceive light. The pupils measured 6 mm in diameter and were completely unreactive to bright light. Ocular mobility was full in all directions. Fundus examination of both eyes showed that the ocular media were clear. The optic discs were pale with ill-defined margins and a pale milky swelling. The retina in each eye appeared normal, apart from moderate narrowing of the arterioles. [Figure 1] a,b. Neurologic examination was otherwise normal. Rectal examination showed Grade-II internal hemorrhoids.
Laboratory studies revealed a hemoglobin of 4.8 gm/dl and hematocrit of 17%. A stool examination showed ova of hookworm and gave a positive test for occult blood. Plain radiographs of the skull and C.T scan of the orbits and brain was normal. Fundus fluorescein angiogram (done seven days after onset of visual loss) showed both optic discs to be hyperfluorescent. The macular area showed a pigment epithelial window defect [Figure 2], a, b, c, d
The patient was given multiple units of packed erythrocytes and normal saline raising his blood pressure and hemoglobin. He was then given a course of intravenous hydrocortisone for three days followed by oral prednisolone. He was also given a course of pentoxifylline, anthelminthics and hematinics. Subsequently, the optic disc swelling increased and the discs became more pale. On day 2, the patient was able to perceive light in both eyes in all quadrants. By day 4 he was able to recognise objects at a distance of 3 feet and could recognise faces. His vision stabilised at 2 weeks to a distant vision of 6/60 after which no improvement occurred.
A 55 year old man was admitted to the hospital for an episode of massive upper gastrointestinal bleeding. He was well until a month earlier, when he had vomiting, burning, pain in the epigastrium followed by malaena. This persisted for a period of four weeks until the day he was admitted into the hospital when he had a bout of massive hematemesis followed by. circulatory collapse. His past medical history revealed that he used to consume about 300 ml of alcohol daily. On further questioning there was no history of illicit liquor consumption. We could elicit no prior history of neurologic or visual symptoms or ocular disease.
On admission, the systolic blood pressure was 80mm Hg. He had severe pallor. The rest of the general and systemic examination were unremarkable. Laboratory studies disclosed the following values: hemoglobin 3.9 gm/dl; hematocrit 13% and a normal coagulation profile. Other laboratory results i.e. blood urea nitrogen, serum creatinine and liver function tests were normal with the exception of a total protein level of 4.7 grn/dl and an albumin of 2.4 gm/dl. Upper GI endoscopic examination s! .red a large ulcer occupying the base and medial border of the duodenal bulb. Multiple erosions were seen surrounding the ulcer.
The patient was given multiple units of packed erythrocytes and saline raising his blood pressure to 110/70 mm Hg and hemoglobin to 12 gm/dl. The patient was under observation in the ward, when two days later he complained of diminished vision in both eyes. He had a rapid deterioration in visual acuity in both eyes and over a span of four hours became completely blind.
On examination, both eyes could not perceive light. The pupils measured 5 mm in diameter and were completely unreactive to light. Ocular mobility was full with a coarse gaze-evoked nystagrnus. Fundus examination revealed a pale milky swelling of the optic disc. The retina appeared normal except for a few scattered nerve fiber layer hemorrhages. Neurologic examination was normal. Plain radiographs of the skull, both orbits and optic foramina were unremarkable.
The therapeutic regimen consisted of hydrocortisone and then prednisolone, ranitidine, antacids and hematinics. The optic disc swelling increased slightly and later the discs became more pale. Two weeks after the advent of visual loss, the patient had not recovered any vision in either eye.
Johnson et a1  have done a histopathologic study of visual loss after blood loss and acute hypotension, adding pathologic documentation to the profile of a well described entity that has many mystifying features.
With few exceptions, affected patients are over 40 years. Many have intercurrent systemic illness, but risk factors for arteriosclerosis are not prominent. Visual loss typically follows repeated hemorrhage. It is exceedingly rare, but has occurred in healthy persons suffering single, even severe, bleeding episodes after war injuries . The source of remote bleeding appears irrelevant. Rather it is the concurrence of hypotension and anemia that predisposes to optic nerve infarction. In fact, Presencia et a1  have noted that in all documented cases of bilateral complete amaurosis, hemoglobin has always measured less than 5.0 gm/dl.
Loss of vision may be unilateral but is often bilateral, ranging from irreversible total blindness to mild transient deficits. Although the onset is usually prompt at the time of blood loss, it is delayed more than 3 days in as many as a third of cases, and beyond 10 days in some instances. Visual field loss is compatible with nerve fiber bundle damage. Results of initial fundus examination may be entirely normal, reflecting retrobulbar involvement of the nerve. Several days later, mild disc edema often appears to affect the retina (arteriolar narrowing, cotton wool spots, retinal edema, cherry-red spot) of the optic nerve head (pallid disc edema). Approximately 50% of patients experience some recovery of sight and 10 to 15% recover completely .
Acute systemic hypotension without documented anemia is unlikely to cause optic nerve infarction.
When visual loss does follow hypotension, anaesthetics, or cardiac arrest, the lesions are generally found in the parietal and occipital lobes, but not in the optic nerves or retina. The characteristic hemispheric brain lesions in these circumstances are two types (1) infarctions in the border zones between the cerebral arteries and (2) diffuse cerebral cortical neuronal death. Indeed most patients who suffer optic nerve infarction after repeated systemic hemorrhage apparently recover without other signs of neurologic damage. Therefore, when hypotension produces optic nerve infarction, it is evidently mild enough to spare the hemispheric watershed regions, and must be associated with another risk factor that makes the optic nerve vulnerable. In some patients, that extra risk factor may be arteriosclerosis.
In patients such as ours, vascular disease was not present, and we presume that anemia was the critical extra risk factor. The optic nerve infarction in such cases seems to differ from that which occurs in patients with arteriosclerosis, in that it usually is centered more posteriorly - in the orbital rather than the juxtalaminar optic nerve.
Johnson et al sub hypothesize that the locus of optic nerve infarction after hypotension depends in part on pre-existing risk factors: In patients with arteriosclerosis they presume that the lumina and perhaps autoregulatory mechanisms of terminal ciliary vessels in the juxtalaminar optic nerve are compromised by hyalinosis, causing this region to be relatively poorly perfused. With a further drop in perfusion pressure during systemic hypotension, the nerve head becomes infarcted. The optic nerve head may be selectively vulnerable since its circulation is subjected to the high tissue hydrostatic pressure exerted by intraocular tension .
On the other hand, in patients such as ours whose vasculature is normal, the nerve head is less vulnerable than the core of the orbital position, which may be most remote from an arterial supply. Unlike the juxtalaminar region of the nerve, which has rich vascular anastomotic networks, the intraorbital segment is nourished primarily by fragile centripetal pial endarteries, with a variable contribution in its anterior position of centrifugal, intraneural branches of the central retinal artery. The combination of pre-existing anemia and hypotensive ischernia probably results in hypoxia leading to edema that gradually compresses the thin pial vessels to produce axial infarction. Because this portion of the nerve has room to expand, the infarctive process is slower than in AION, which occurs in the densely packed confines of the scleral canal. Thus, there may be a latency in reporting visual loss after the hypotensive event.
Johnson et a1  believe that visual loss after hypotension is of the following three general types:
1. Hemispheric : Sustained and profound hypotension in a non-anemic patient without arteriolar sclerosis causes watershed white and gray matter infarction in the parietal and occipital lobes. The optic nerves tend to be spared.
2. Juxtalaminar optic nerve : Brief hypotension in a patient with arteriosclerotic risk factors is likely to cause juxtalaminar optic nerve infarction that is indistinguishable from spontaneous AION.
3. Orbital optic nerve : Hypotension in an anemic patient without arteriosclerotic risk factors favours infarction in the orbital optic nerve where pial end-vessels are subject to compression from hypoxic edema.
We believe that both our patients belong to the last category. Both these patients were middle aged men with no prior history of systemic, ocular or neurologic disease. There were no risk factors for arteriosclerosis in either of the two patients. Systemic hypotension was the underlying factor which precipitated the onset of visual deterioration - in one the cause being a massive gastrointestinal hemorrhage, in the other severe vomiting. Both patients had severe anemia (Hb values of 3.9 gm/dl and 4.8 gm/dl) at the time of onset of visual loss. Thus it was the combination of hypotension and anemia in these individuals that led to an irreversible visual loss. As iron deficiency anemia due to helminthiasis is common in developing countries hypotensive episodes in anemic subjects may be an important etiological factor in acute visual loss.
We are grateful to Dr. Kanti Mody, Hon. Ophthalmic Surgeon, Jaslok Hospital and Research Centre for conducting fundus fluorescein angiogram and fundus photography on the patients reported in this article.
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