Vision Loss After Lumbar Epidural Steroid Injection
1998; Lippincott Williams & Wilkins; Volume: 86; Issue: 1 Linguagem: Inglês
10.1213/00000539-199801000-00024
ISSN1526-7598
Autores Tópico(s)Anesthesia and Pain Management
ResumoVisual loss associated with retinal hemorrhages after laparoscopy performed under general anesthesia has been previously reported in the anesthesiology literature [1]. This complication has been reported only once after an epidural steroid injection in the anesthesia literature [2]. We report a case of acute monocular vision loss secondary to multiple retinal hemorrhages after a lumbar epidural steroid injection. Case Report A 49-yr-old woman presented to the pain clinic with a history of low back pain unresponsive to pharmacologic treatment radiating into her left hip and left lower extremity. The patient was markedly obese [weight 138 kg, body mass index 51 kg/m [2]]. She had undergone previous psychotherapy for depression and obesity and had unsuccessfully attempted weight loss programs. Deep tendon reflexes were normal, and there were no motor or sensory deficits. Radiological studies of the lumbosacral spine revealed lumbosacral degenerative disc disease and degenerative facet disease. After the examination, the patient received an epidural steroid injection consisting of 20 mL 0.125% bupivacaine with 80 mg methylprednisolone. The infusion was administered slowly over 1 min with a 17-gauge Tuohy needle at the L2-3 interspace, with the patient in the sitting position. There was no aspiration of cerebrospinal fluid or blood. After the injection, the patient had a transient episode of lightheadedness, but her blood pressure and heart rate remained stable. Later that evening, she became aware of decreased vision in the right eye. An ophthalmologic examination revealed visual acuity of 20/400 in the right eye and 20/40 in the left eye. Her vision had been normal in both eyes. Dilated fundus examination revealed large intraretinal hemorrhages in both eyes, concentrated in the macular areas, involving the right eye more than the left (Figure 1). There were also smaller hemorrhages in the retinal midperiphery of each eye.Figure 1: a, Fundus photograph of the right eye 4 days after the epidural injection reveals many intraretinal hemorrhages with a petaloid morphology clustered in the macula. A dense central hemorrhage involves the fovea (central macula), causing a central scotoma and reduced visual acuity (20/400). b, Fewer retinal hemorrhages are present in the asymptomatic left eye, photographed on the same day. The fovea (central macula) is not obscured by blood. Therefore, the central visual acuity is spared.Three weeks after the epidural injection, her visual acuity had improved to 20/200 in the right eye, and at the 3 mo visit, the visual acuity was 20/70. Despite the improved vision, the patient still noted a central scotoma in her right eye. The hemorrhages had largely resorbed, but a tiny central macular fibrin deposit was still present (Figure 2). Follow-up examinations over 24 mo revealed gradual improvement in visual acuity to 20/40 right eye and resolution of the macular deposits.Figure 2: a, By 3 mo after the epidural injection, the hemorrhages were barely visible. A tiny speck of residual fibrin persists in the central fovea. The patient's visual acuity was 20/70, and she continued to complain of a central scotoma. b, The hemorrhages had nearly completely resolved. The left eye remained asymptomatic throughout the follow-up period of 18 mo.Discussion Although epidural injection is safe for most patients, there are potential complications, including headache from inadvertent dural puncture, nausea and vomiting, hypotension, meningitis, epidural abscess, Cushing's syndrome, and steroid myopathy [3-6]. Vision loss has been reported after various anesthetic procedures. In some cases, it is secondary to cerebral, optic nerve, or retinal ischemic changes during general or spinal anesthesia [2,7-9]. Incorrect patient positioning may result in central retinal artery occlusion from ocular compression in patients lying in a prone position during general or spinal anesthesia [10]. Temporary vision loss has also been described after the administration of ketamine [11] and as a result of glycine absorption during transurethral prostate resection [12]. Other eye injuries reported after anesthesia include corneal abrasions, chemical injuries, and blunt ocular trauma [13]. Previously reported cases of visual loss associated with retinal hemorrhages after epidural injections are summarized in Table 1. Two of these patients received epidural injections of 120 mL of saline, whereas the others received 40 mL of a local anesthetic containing corticosteroid. Five patients had unilateral involvement, whereas three patients had bilateral retinal hemorrhages. Only one of the patients did not regain the pretreatment level of vision [2,14-16].Table 1: Summary of Reported Cases of Retinal Hemorrhage After Epidural InjectionAs with the previously reported cases, our patient developed visual symptoms shortly after her epidural injection. She was found to have retinal hemorrhages with a petaloid morphology concentrated in the macular area. This pattern of hemorrhages has been noted in previous cases [15,16]. Previous research suggests that rapid epidural injections cause a sudden increase in intracranial pressure. This increase in cerebrospinal fluid pressure causes an increase of retinal venous pressure, which may result in retinal hemorrhages [2,14-19]. The optic nerve and its central retinal vein are surrounded by an extension of the subarachnoid space. If the increase in pressure is more severe, retinal veins may rupture, resulting in preretinal or vitreous hemorrhage, as noted in a few of the reported patients after epidural injections [2,14,15]. The ophthalmoscopic findings in patients with retinal hemorrhages after epidural injection are similar to those in patients with subarachnoid hemorrhage, valsalva retinopathy, or shaken-baby syndrome [2,15,16]. Recent anesthesia literature usually mentions epidural injection volumes of 20 mL or less when a local anesthetic is included. Although some studies suggest that the efficacy of epidural steroid injection may be related to the volume injected, this relationship remains unconfirmed [20-22]. Very small injection volumes of 1 or 2 mL are possible if corticosteroid alone is injected [20]. Although our patient received an injection volume of only 20 mL, all of the previously reported cases involved injection volumes of 40-120 mL [2,14-16]. Some studies have reported a relationship between the injection volume and a subsequent increase in intracranial pressure [23,24]. Therefore, the risk of retinal hemorrhages may be increased with larger epidural injection volumes. In view of the clinical features of our patient and those discussed in the literature and because of the relationships among epidural, intracranial, and retinal venous pressures, there may be specific factors that increase the likelihood of retinal hemorrhage after epidural injection. It is possible that obesity, hypertension, coagulopathies, preexisting increase of cerebrospinal fluid pressure (as observed in pseudotumor cerebri), and retinal vascular diseases (such as diabetic retinopathy) may be risk factors for this complication. It is advisable to be cautious when injecting fluid into the epidural space. A slow injection rate and use of the least volume necessary to accomplish the desired analgesia may help to reduce the risk of this uncommon complication of epidural injections.
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