Salvage of vision after hypotension-induced ischemic optic neuropathy

A Successfully Treated Case of Posterior Ischemic Optic Neuropathy That Developed during Antihypertensive Therapy for Hypertensive Emergency

A 33-year-old woman developed hypertensive emergency (268/168 mmHg) with renal failure and hypertensive retinopathy. Four hours after the initiation of antihypertensive therapy with the continuous infusion of nicardipine, her blood pressure (BP) decreased to 168/84 mmHg; however, the patient developed blindness. She was diagnosed with posterior ischemic optic neuropathy (PION). Her BP was maintained at approximately 175/90 mmHg until her vision improved. Olmesartan was initiated on day 13, and her BP decreased to approximately 135/95 mmHg without the re-exacerbation of vision loss. Although the prognosis of PION is poor, its early diagnosis and gradual antihypertensive therapy may help preserve the patient's vision.

Binasal Field Defect in Non-arteritic Anterior Ischemic Optic Neuropathy

Non-arteritic anterior ischemic optic neuropathy (NAION) is the most common cause of optic neuropathy in older adults and is usually associated with an altitudinal visual field defect. Binasal hemianopia is a rare visual field presentation, and most causes are due to ocular pathology instead of brain pathology. It is an infrequent finding in NAION. We report a rare presentation of binasal hemianopia visual field defect in a patient with NAION. This a case of an elderly lady with underlying uncontrolled type 2 diabetes mellitus, hypertension, and dyslipidemia who presented with a sudden onset of painless blurring of vision in the left eye. She had a similar episode of blurred vision involving the other eye two years ago. Her visual acuity was reduced in both eyes. Humphrey visual field showed a binasal field defect. Fundoscopy showed mild hyperemic optic disc swelling in the left eye and a pale disc in the right eye. The CT scan and MRI were normal. She was co-managed with the medical team to control her systemic risk factors. Although NAION is the most common cause of optic neuropathy in older adults, binasal hemianopia is a rare visual field presentation in NAION. The history and assessment from this case add important information toward diagnosing NAION.

Preservation of Vision after Early Recognition of Anterior Ischemic Optic Neuropathy in a Patient with Sepsis

Non-arteritic ischemic optic neuropathy (NAION) can rarely occur in the setting of sudden vascular compromise, especially in patients with a "disk-at-risk" appearance. Anemia and hypotension are believed to be the main precipitators of shock-induced NAION. Early recognition of this phenomenon can prevent further visual loss and result in partial visual recovery. We here present a 56-year-old patient who developed NAION characterized by optic disc edema in both eyes and visual loss in the left eye secondary to hypotension in the setting of septic shock. He received aggressive blood pressure management (stopping all his anti-hypertensives, hydration, and midrodrine) which resulted in stabilization of vision in the right eye and likely prevented further visual loss in the left eye.

Dialysis-Associated Nonarteritic Anterior Ischemic Optic Neuropathy: A Case Series and Review

BACKGROUND

Dialysis-associated nonarteritic ischemic optic neuropathy (DA-NAION) occurs secondary to intradialytic hypotension often with catastrophic consequences and is one of the rare situations where NAION can recur in the same eye. We describe 3 cases of DA-NAION associated with hypotension, review the current literature on DA-NAION, and provide recommendations for decreasing the risk of intradialytic hypotension.

METHODS

In addition to describing 3 cases of DA-NAION, PubMed was searched for all reports of DA-NAION in adults with documented episodes of hypotension preceding the onset of NAION. A total of 50 eyes of 31 patients were included. Age, visual acuity at presentation, rate of bilateral involvement at presentation, sequential involvement of the fellow eye, and recurrence of NAION in the same eye were analyzed.

RESULTS

We found that most cases of DA-NAION occur in relatively young patients (47.7 ± 14.7 years) with a high rate of bilateral involvement at presentation (23%) and bilateral sequential involvement (39%). Vision loss is severe with 64% of patients presenting with 20/200 acuity or worse in the involved eye and 19% of patients with final visual acuity of 20/200 or worse in both eyes. 3 patients (9.7%) had recurrence of NAION in the previously affected eye.

CONCLUSIONS

Neuro-ophthalmologists have an important role in identifying patients who have suffered DA-NAION and communicating their findings to nephrologists to minimize the chance of involvement of the fellow eye and recurrence in the same eye. Intradialytic blood pressure must be closely monitored, and fluid balance, dialysate composition, and dialysis protocol must be optimized to prevent occurrence of intradialytic hypotension, which is the culprit for DA-NAION.

Non-Arteritic Anterior Ischemic Optic Neuropathy (NAION) Following a Hypovolemic Episode of Gastric Bleeding

Non-arteritic anterior ischemic optic neuropathy (NAION) is a rare complication following acute bleeding. Patients present with varying vision loss and visual field defects. NAION is more commonly developed in patients with systemic disorders that may affect normal blood flow such as hypertension and diabetes. In this case, we report a 54-year-old man who complained of vision blurring following an episode of acute gastric bleeding. This report aims to review the pathology of this condition and present the findings of newer non-invasive imaging modalities of the vascular layers of the posterior pole of the eye like optical coherence tomography angiography (OCTA), which facilitates the proper diagnosis and prognosis of such cases. Finally, we present the management options for this patient with antiplatelet treatment.

Neuropatía óptica asociada con lesión de Dieulafoy

Objetivo:  describir el caso de un paciente del Hospital de San José de Bogotá con hemorragia del tracto digestivo superior secundaria a lesión de Dieulafoy, que presentó cuadro compatible con neuropatía óptica anterior isquémica no arterítica (NOIANA). Se hace una revisión narrativa y búsqueda sistemática de la literatura para determinar las características clínicas, demográficas, tratamiento y pronóstico visual de los pacientes con NOIANA. Materiales y métodos: reporte de caso, revisión narrativa y búsqueda sistemática de la literatura en las bases de datos Medline (vía Ovid) y Embase de NOIANA secundaria a hipovolemia. Se analizaron las variables sociodemográficas, clínicas, diagnóstico, condiciones asociadas, tratamiento y pronóstico visual. El análisis estadístico se realizó mediante frecuencias absolutas y relativas. Resultados:  la mejoría de agudeza visual final en los pacientes que presentaron un episodio de NOIANA es incierta. En 42% hubo algún tipo de mejoría de la agudeza visual, independiente del tratamiento recibido. Menos del 50% de los casos clínicos reportados incluidos en este estudio que recibieron tratamiento con corticoides intravenosos mejoraron la visión. Discusión: la NOIANA por choque hipovolémico es una entidad infrecuente y poco reportada que puede generar cambios irreversibles en la agudeza visual, por lo que es importante sospecharla y detectarla para dar un manejo oportuno. Este caso de NOIANA es uno de los pocos descritos como secundarios a hemorragia digestiva y el primero asociado con lesión de Dieulafoy.

Posterior ischemic optic neuropathy: Perioperative risk factors

Perioperative posterior ischemic optic neuropathy (PION) is a rare but devastating condition. Visual impairment is commonly bilateral, profound, and irreversible. The most frequently associated triggering events are spine surgeries, other orthopedic surgeries, cardiac bypass surgeries, and radical neck dissection. The etiology is multifactorial. The most commonly reported risk factors are severe and prolonged hypotension, anemia, hemodilution, orbital and periorbital edema, direct orbital compression by prone position, and abnormal autoregulation. This review discusses the current literature on perioperative PION and includes a study conducted by our group to investigate the perioperative risk factors of PION in order to better understand the pathogenesis and help identify high-risk patients. Our results provide further corroborating evidence that PION is associated with spinal, cardiovascular, and abdominal surgeries, longer duration of procedure, and facial edema. Anemia and chronic hypertension are frequent risk factors. Treatment for perioperative PION is uncertain and depends largely on the immediate reversal of hemodynamic alterations. Hence, it is important to identify patients at risk and accordingly take prophylactic measures to prevent its occurrence. Optimizing hemoglobin levels, hemodynamic status, and tissue oxygenation is crucial.

Visual Loss Post Ross Procedure in an Adolescent With Newly Diagnosed Mucopolysaccharidosis Type II

Perioperative visual loss is a rare but serious complication after cardiac surgery. The etiology is not fully understood, and there is no consensus on the optimal management of this condition. A 15-year-old male patient developed severe visual impairment attributed to nonarteritic anterior ischemic optic neuropathy after a Ross aortic root replacement procedure. A new diagnosis of the lysosomal storage disorder, mucopolysaccharidosis type II (Hunter syndrome), was subsequently made, raising questions about the pathogenesis of this devastating postoperative complication.

Visual Impairment After Haemodialysis

Hypotension is the most frequent complication of haemodialysis. We report a case of acute visual impairment after one session of haemodialysis in a context of an acute optic neuropathy. The immunological and serological studies were negative. The records of hypotension greater than usual after the dialysis session that coincided with the visual complaints strongly suggest the dialysis-induced hypotension is the underlying mechanism of this non-arteritic anterior ischemic optic neuropathy.

Hyperhomocysteinemia in bilateral anterior ischemic optic neuropathy after conventional coronary artery bypass graft: a case report

Background

The incidence of anterior ischemic optic neuropathy after coronary artery bypass graft procedures ranges from 1.3 to 0.25%. The mechanisms of anterior ischemic optic neuropathy after cardiovascular procedures remain undefined but many systemic and related-to-surgery risk factors could underlie anterior ischemic optic neuropathy. In this case, we report a rare presentation of a bilateral anterior ischemic optic neuropathy after coronary artery bypass graft and speculate on the preoperative hyperhomocysteinemia as an independent risk factor for anterior ischemic optic neuropathy.

Case presentation

A 56-year-old white man, a tobacco smoker with type 2 diabetes and coronary artery disease, underwent a conventional coronary artery bypass graft with extracorporeal circulation. In spite of ongoing anti-aggregation, antithrombotic, and vasodilator therapy, 10 days after the surgery he complained of severe bilateral visual loss. Funduscopy and fluorescein angiography revealed a bilateral anterior ischemic optic neuropathy. Analysis of preoperative laboratory tests revealed hyperhomocysteinemia.

Conclusion

Hyperhomocysteinemia could increase the risk of ocular vascular damage and bilateral ocular involvement in patients who have undergone conventional coronary artery bypass graft.

[Shock-induced anterior ischemic optic neuropathy from hemorrhagic anemia]

A 51-year-old diabetic and overweight male presented to our eye clinic with right-sided impairment of visual acuity and scotoma. A thorough work-up had been carried out at our institute 9 months prior to this event due to left-sided nonarteriitic anterior ischemic optic neuropathy (NAION). Despite the similarity of visual symptoms in the currently and previously affected eyes microcystic anemia (Hb 81 g/dl) associated with severe hemorrhoidal bleeding was diagnosed. The patient underwent surgical hemorrhoidectomy and received two red blood cell concentrates. Therefore, this article reports on an extraordinarily rare case of shock-induced anterior ischemic optic neuropathy (SIAION) caused by hemorrhoidal bleeding.

Hypotension-induced blindness in haemodialysis patients

Hypotension is a commonly encountered complication in haemodialysis patients and is a significant cause of morbidity and mortality. Bilateral visual loss in dialysis induced hypotension remains poorly recognized as a complication by both renal physicians and ophthalmologists. We report 2 cases of patients on renal dialysis who suffered severe longstanding hypotension with bilateral non-arteritic anterior ischaemic optic neuropathy. Both patients experienced bilateral loss of vision over a short time period. We feel that physicians must be aware of patients complaining of painless visual loss in this high risk group, as control of blood pressure may be the most important factor in prevention of this visually devastating condition.

Acute bilateral visual loss related to orthostatic hypotension

A 50-year-old man had undergone lumbar vertebral surgery and was confined to bed in the supine position for three months. When he sat up from the prolonged supine position, he showed clinical signs of orthostatic hypotension and reported decreased vision in both eyes. He also had underlying anemia. Ophthalmologic findings suggested bilateral anterior ischemic optic neuropathy (ION) as the cause of the visual loss. Although there are numerous reports of ION in the setting of hemodynamic compromise, such as systemic hypotension, cases of ION-associated orthostatic hypotension are very rare.

Cortical Blindness due to Bilateral Occipital Infarcts in a Renal Failure Patient with Prostate Cancer: A Rare Complication of Hemodialysis

Loss of vision is a rare complication seen in hemodialysis patients. It is thought to develop because of the hypotension that can be observed during dialysis. This paper involves a patient with acute loss of vision during hemodialysis due to bilateral occipital infarcts.

Non-arteritic ischaemic optic neuropathy after first return to haemodialysis

The authors present an interesting case of non-arteritic anterior ischaemic optic neuropathy (NAION) after 2 h of haemodialysis, in a 42-year-old Caucasian woman with anaemia (haemoglobin 7.1 g/dl) uraemia (56.3 mmol/l), spurious hypotension (42/26 mm Hg) and previous history of anterior ischaemic optic neuropathy (AION) in the other eye. Thirteen cases of haemodialysis related NAION in adults have been reported to date. NAION is produced when oxygen delivery to the optic nerve is compromised resulting in hypoxic swelling, nerve compression in the optic canal and ischaemia of the optic nerve head. It typically presents as a sudden, unilateral and painless inferior visual field defect with a fixed unreactive pupil after a period of relative hypotension. Clinicians should be aware of this unusual complication when considering and explaining dialysis options, particularly in patients with other risk factors such as hypotension, anaemia, significant uraemia and previous history of AION.

Bilateral anterior ischemic optic neuropathy in patients on dialysis: A report of two cases

Patients under chronic dialysis treatment suffer from atherosclerotic disease and anemia more frequently than the normal population. This, together with the frequent hypotension, put these patients at increased risk for anterior ischemic optic neuropathy (AION), which may be bilateral and blinding. We present two cases of patients under chronic dialysis who developed bilateral AION after hypotensive events. Bilateral involvement is not unusual in renal replacement patients who suffer from AION. Efforts should be focused on prevention of this complication by improving anemia and blood pressure control because once established, treatment will probably be ineffective.

Nonarteritic anterior ischaemic optic neuropathy in Addison's disease

PURPOSE

To report three cases of Nonarteritic anterior ischaemic optic neuropathy (NAAION) in patients with Addison's disease.

METHODS

We present a retrospective review of patients presenting with NAAION with underlying Addison's disease.

RESULTS

Three eyes of two young patients presented with NAAION. Both patients had underlying Addison's disease with episodes of prolonged hypotension.

CONCLUSION

To our knowledge, this is the first published report of NAAION associated with Addison's disease. As hypotension may be one of the few situations, in which NAAION may be treatable and the visual loss reversible, it is important to recognize and treat sustained episodes of hypotension in these individuals.

Perioperative visual loss in ocular and nonocular surgery

Incidence estimates for perioperative vision loss (POVL) after nonocular surgery range from 0.013% for all surgeries up to 0.2% following spine surgery. The most common neuro-ophthalmologic causes of POVL are the ischemic optic neuropathies (ION), either anterior (AION) or posterior (PION). We identified 111 case reports of AION following nonocular surgery in the literature, with most occurring after cardiac surgery, and 165 case reports of PION following nonocular surgery, with most occurring after spine surgery or radical neck dissection. There were an additional 526 cases of ION that did not specify if the diagnosis was AION or PION. We also identified 933 case reports of central retinal artery occlusion (CRAO), 33 cases of pituitary apoplexy, and 245 cases of cortical blindness following nonocular surgery. The incidence of POVL following ocular surgery appears to be much lower than that seen following nonocular surgery. We identified five cases in the literature of direct optic nerve trauma, 47 cases of AION, and five cases of PION following ocular surgery. The specific pathogenesis and risk factors underlying these neuro-ophthalmic complications remain unknown, and physicians should be alert to the potential for loss of vision in the postoperative period.

Central and Paracentral Visual Field Defects and Driving Abilities

The effect of central and paracentral visual field defects on driving abilities has until now received little attention. To date studies and surveys have concentrated on visual acuity and peripheral field loss. Here we summarise for the first time those diseases causing central visual field defects likely to be associated with binocular visual acuity adequate for driving.

Perioperative visual loss after nonocular surgeries

PURPOSE

To review the current knowledge of persistent visual loss after nonocular surgeries under general anesthesia.

DESIGN

Perspective.

METHODS

Literature review.

RESULTS

The incidence of perioperative visual loss after nonocular surgeries ranges from 0.002% of all surgeries to as high as 0.2% of cardiac and spine surgeries. Any portion of the visual pathways may be involved, from the corneas to the occipital lobes, but the most common site of permanent injury is the optic nerves, and the most often presumed mechanism is ischemia. Anterior ischemic optic neuropathy (AION) is more prevalent among cardiac surgery patients and posterior ischemic optic neuropathy (PION) predominates among those who have had spine and neck procedures. Patients range from age five to 81 years and typically awake with severe bilateral visual loss. Multiple factors have been proposed as risk factors for perioperative ION, including long duration in the prone position, excessive blood loss, hypotension, anemia, hypoxia, excessive fluid replacement, use of vasoconstricting agents, elevated venous pressure, head positioning, and a patient-specific vascular susceptibility that may be anatomic or physiologic. However, the risk factors for any given patient or procedure may vary and are likely multifactorial.

CONCLUSIONS

If, when an ophthalmologist is consulted for a patient with perioperative visual loss, an obvious ocular cause is not apparent, urgent neuroimaging should be obtained to rule out intracranial pathology. Anterior and posterior ION should be considered and careful documentation is essential. Currently, the pathogenesis of perioperative ION remains unclear, and preventive and therapeutic measures remain elusive.

Changes in intraocular pressure due to surgical positioning: studying potential risk for postoperative vision loss

STUDY DESIGN

Parallel group design.

OBJECTIVE

Compare the intraocular pressure responses in the prone flat versus prone Trendelenburg's position.

SUMMARY OF BACKGROUND DATA

Postoperative vision loss (PVL) complicates approximately 0.05% of spine surgeries. Prone positioning is considered a risk factor because it increases intraocular pressure, which may decrease perfusion pressure to the optic nerve (perfusion pressure = mean arterial pressure - intraocular pressure [IOP]). The prone Trendelenburg's position is often used during spine surgery; however, its effect on optic nerve perfusion is unknown. The purpose of this study is to compare the IOP responses in the prone flat versus prone Trendelenburg's positions to determine if prone Trendelenburg's position also risks PVL.

METHODS

Twenty subjects randomized into 2 groups. Group 1 lay in the prone flat position (0 degrees). Group 2 lay in the prone Trendelenburg's position (-7 degrees). IOPs were measured with a hand-held applanation tonometer while seated, 1 minute after assuming the group's position (Time 0), and at 10-minute intervals for 60 minutes.

RESULTS

The differences in mean IOPs with respect to positions and time were significant (P = 0.0001, P = 0.000). There was a significant difference between sitting and all other times for both groups. In Group 1, there was a significant difference in IOP between Time 0 and all other times prone flat (P < 0.05). In Group 2, there was a significant difference in IOP between Time 0 all other times prone Trendelenburg (P < 0.05).

CONCLUSION

IOP increases in the prone Trendelenburg's position, and when combined with other factors, may be a risk factor for PVL. The pathophysiology is discussed and suggestions for clinicians are made.

Ophthalmologic complications associated with prone positioning in spine surgery

Visual impairment and blindness associated with general anesthesia and prone positioning in spine surgery have been increasing in incidence over the past several decades. Corneal abrasion, the most common ophthalmologic injury, is usually self-limiting. However, prolonged surgical procedures (>7 hours) associated with acute blood loss anemia, hypotension, and hypoxia may lead to posterior ischemic optic neuropathies. Direct pressure to the periorbital region of the eye can cause increased intraocular pressure and blindness as the result of central retinal artery occlusion. Hypoxia and cerebral embolism are associated with occipital cortical infarct or cortical blindness. The prognosis for visual recovery from ischemic neuropathy and retinal artery occlusion is poor. Cortical blindness usually improves to varying degrees. Effective treatment of perioperative amaurosis is lacking and usually ineffective, making prevention the cornerstone of management. To best prevent permanent ophthalmologic complications associated with prone positioning during spine surgery, orthopaedic surgeons should be aware of pathophysiology and related risks associated with spine surgery in the prone position, and initiate preventive measures and predictable treatment options.

Delayed ischemic optic neuropathy after surgery on skull base meningiomas successfully treated with nimodipine and rheological therapy: report of two cases

Two patients operated on because of skull base meningiomas experienced delayed ischemic optic neuropathy with loss of vision in one eye on days 6 and 12 after surgery. Treatment with nimodipine and rheological therapy was effective in restoring visual acuity. Possible pathophysiological mechanisms and treatment options are discussed.

Recovery of postoperative visual loss following treatment of severe anaemia

A 29-year-old pregnant woman noted acute visual loss following emergent Caesarean section complicated by excessive uterine bleeding. Postoperative visual acuity was count fingers in both eyes. Funduscopic changes were consistent with a diagnosis of anaemia-associated ischaemic optic neuropathy and retinopathy. One month later, because of persistent anaemia and poor visual recovery, blood transfusion was given. Following transfusion, the patient's vision improved over the next 6 months. In an otherwise healthy patient, visual loss associated with postoperative blood loss may still be partially reversible with correction of the anaemia, even after a delayed period of time.

Nonarteritic anterior ischemic optic neuropathy

PURPOSE OF REVIEW

Nonarteritic anterior ischemic optic neuropathy remains a disease that is poorly understood in many aspects. The clinical presentation may diverge significantly from the classic unilateral, painless, sudden vision loss affecting patients over the age of 50 years. This variability might make nonarteritic anterior ischemic optic neuropathy hard to differentiate from optic neuritis and arteritic ischemic optic neuropathy. The course of nonarteritic anterior ischemic optic neuropathy is also variable, often sequentially affecting the other eye.

RECENT FINDINGS

Visual recovery has been reported, but it is not the rule. Multiple risk factors have been proposed, including crowded disc, atherosclerosis, diabetes, hyperlipidemia, hypertension, hypotension, hemoconcentration, hemodilution, and hypercoagulable states. The optic nerve damage in nonarteritic anterior ischemic optic neuropathy appears to result from a perfusion insufficiency in the short posterior ciliary arteries leading to infarction of the retrolaminar portion of the optic disc. The underlying mechanisms are still unclear, however. Multiple medical and surgical treatment options have been investigated, including optic nerve sheath decompression, standard and megadose corticosteroids, levodopa, carbidopa, hyperbaric oxygen, and neuroprotective agents, but no proven effective treatment is currently available.

SUMMARY

Intense investigations in humans and animals are under way. Hopefully these studies will enhance our understanding of the risk factors and pathophysiology of nonarteritic anterior ischemic optic neuropathy and aid in developing new strategies for prevention and treatment.

Anterior ischaemic optic neuropathy after coronary artery bypass graft: the role of anaemia in diabetics

PURPOSE

To ascertain factors associated with anterior ischaemic optic neuropathy (AION) following coronary artery bypass graft (CABG) in a Lebanese population.

METHODS

A retrospective chart review of consecutive CABG performed over a 5-year period (1995-1999) in one medical centre. A comparison of clinical characteristics was carried out between AION cases and subjects free from AION. The variables analysed included history of diabetes as well as preoperative, intraoperative, or postoperative values of haematocrit, blood sugar, oxygen saturation, and arterial blood pressure.

RESULTS

A total of 1,594 persons were included. Three subjects experienced acute visual loss from AION following CABG, all had diabetes mellitus, and two suffered from severe postoperative anaemia. Among diabetics (n=484), the risk of AION was significantly higher in subjects with postoperative haematocrit falling below 22 (28.6%) than the rest (0.21%) (P=0.001). Blood transfusion was given in two subjects with prompt visual recovery.

CONCLUSIONS

Severe anaemia in patients undergoing CABG appears to be a risk factor for AION, especially in diabetics, and needs prompt correction to prevent or reverse the ischaemic ocular events.

Neuro-Ophthalmic Emergencies for the Neurologist

A variety of acute neurologic disorders present with visual signs and symptoms. In this review the authors focus on those disorders in which the clinical outcome is dependent on timely and accurate diagnosis. The first section deals with acute visual loss, specifically optic neuritis, ischemic optic neuropathy (ION), retinal artery occlusion, and homonymous hemianopia. The authors include a discussion of those clinical features that are helpful in distinguishing between inflammatory and ischemic optic nerve disease and between arteritic and nonarteritic ION. The second section concerns disc edema with an emphasis on the prevention of visual loss in patients with increased intracranial pressure. The third section deals with abnormal ocular motility, and includes orbital inflammatory disease, carotid-cavernous fistulas, painful ophthalmoplegia, conjugate gaze palsies, and neuromuscular junction disorders. The final section concerns pupillary abnormalities, with a particular emphasis on the dilated pupil and on carotid artery dissection. Throughout there are specific guidelines for the management of these disorders, and areas are highlighted in which there is ongoing controversy.

Efficacy of levodopa and carbidopa on visual function in patients with non-arteritic anterior ischaemic optic neuropathy

The benefit of levodopa and carbidopa therapy in improving visual function in patients with non-arteritic anterior ischaemic neuropathy (NAION) was evaluated. Twenty-four subjects with NAION were randomly selected to receive either levodopa-carbidopa or a placebo. Visual functions of neither the study nor the placebo groups showed improvement. Side effects of levodopa such as dizziness, orthostatic hypotension, vomiting and cardiac arrhythmia were seen. Levodopa and carbidopa had no therapeutic effect on visual recovery in our patients with NAION.

Ischemic optic neuropathy in dialyzed patients: A previously unrecognized manifestation of calcific uremic arteriolopathy

Two patients with end-stage renal disease and on long-term hemodialysis presented with hypotension and an acute unilateral loss of vision. A diagnosis of anterior ischemic optic neuropathy (AION) was made quickly, but despite high-dose steroid therapy, significant vision was not recovered. Temporal artery biopsy results showed extensive medial calcification. The possibility that hypotension, when coupled with calcific uremic arteriolopathy in arteries supplying the optic nerve head, will lead to AION in dialyzed patients is discussed. A short review of AION in the dialysis population is given.

Positioning on surgical table

Positioning on the surgical table is one of the most important steps in any spinal surgical procedure. The "prone position" has traditionally been and remains the most common position used to access the dorsolumbar-sacral spine. Over the years, several authors have focused their attention on the anatomy and pathophysiology of both the vascular system and ventilation in order to reduce the amount of venous bleeding, as well as to prevent other complications and facilitate safe posterior approaches. The present paper reviews the pertinent literature with the aim of highlighting the advantages and disadvantages of various frames and positions currently used in posterior spinal surgery.

Transient visual loss may anticipate occipital infarction from hemodialysis

BACKGROUND

The aim of this study was to report on a patient who had occipital infarction from intradialytic hypotension and review the literature on hemodialysis and visual loss.

METHODS

Neuro-ophthalmologic examination and magnetic resonance imaging (MRI) of the brain were conducted.

RESULTS

A 61-year-old woman had acute onset of a right homonymous superior quadrantic visual field defect during dialysis after several episodes of transient visual loss associated with symptomatic intradialytic hypotension. MRI showed acute infarction in the left occipital lobe.

CONCLUSION

Visual loss is an uncommon complication of hemodialysis. The mechanism usually is related to hypotension and is usually from anterior ischemic optic neuropathy. Although cortical blindness secondary to stroke has been reported as a complication after hemodialysis, we were unable to find another report of visual loss secondary to stroke attributed to intradialytic hypotension with preceding episodes of transient visual loss. Transient visual loss may be a risk factor for stroke during hemodialysis.

Sudden blindness caused by anterior ischemic optic neuropathy in 5 children on continuous peritoneal dialysis1 1Published partially (case 3) in abstract form in Arch Ped 7:437, 2000, and in Pediatr Nephrol 16:C4, 2001

The authors report the occurrence of sudden blindness in 5 children (mean age, 32 months; range, 11 to 60) during continuous peritoneal dialysis regimen. All children presented with loss of light perception, visual fixation and ocular pursuit, and bilateral mydriasis unreactive to bright light. Fundoscopic examination found signs of anterior ischemic optic neuropathy with disc swelling, edema, and hemorrhages. Whereas 1 patient was dehydrated, the 4 other patients appeared well and not dehydrated. Nevertheless, blood pressure was below the normal range in all of them. Therefore, hypovolemia is highly suspected to have been the cause of ischemic optic neuropathy in all cases. Treatment consisted of steroids (4 patients), anticoagulation or antiagregation drugs (3 patients), plasma or macromolecules infusions (2 patients), vasodilatators (2 patients), and transient dialysis interruption (1 patient). One child with hepatic cirrhosis died 4 days later of acute liver insufficiency owing to ischemic hepatic necrosis. The other children had only partial improvement of vision during the following months. Because the prognosis of ischemic optic neuropathy is very poor, diagnosis and treatment of chronic hypovolemia in children on continuous peritoneal dialysis is essential to prevent such a devastating complication.

Unilateral Visual Loss After Cervical Spine Surgery

This is a case report of a patient who underwent an uneventful surgery for atlanto-axial dislocation in the prone position, after which he developed painless, unilateral loss of vision in the immediate postoperative period. Based on the ophthalmologic findings a probable diagnosis of ischemic optic neuropathy (ION) was made. Although he recovered his visual acuity completely in 1 month, the visual field defects and color vision abnormalities persisted. Intraoperative anemia, hypotension, with or without vasculopathic risk factors, and prolonged surgery in the prone position have been reported as major risk factors for the development of this complication following spine surgery. However, this healthy young man had an uneventful surgery with no such intraoperative complications. ION in this patient could have been due to a combination of factors, such as a malpositioned horseshoe headrest and surgery performed in the prone position, both of which have the potential to raise the intraocular pressure and lower the perfusion pressure of the optic nerve/nerve head. Variations in the blood supply of the optic nerve due to the presence of watershed zones could be another explanation for this dreaded complication.

Ischemic optic neuropathy after endoscopic sinus surgery: a case report

For the past 2 decades, endoscopic sinus surgery (ESS) has proven effective for treating paranasal sinus disease. Orbital complications of varying degrees, from mild orbital hematoma to catastrophic blindness, have been widely reported. However, defects of the visual field resulting from post-ESS ischemic optic neuropathy (ION) has not to our knowledge been reported in the literature. We were presented with a 51-year-old male patient suffering from loss of sight following an otherwise uneventful ESS. ION is a rare condition, characterized by acute or subacute postoperative loss of sight. The major risks for developing ION include intraoperative anemia, hypotension and systemic illnesses such as hypertension, diabetes or renal failure. Otorhinolaryngologists should be aware that this condition may occur following an uncomplicated ESS procedure, and patients should be given prompt opthalmological consultation when loss of sight is diagnosed postoperatively. Early aggressive and rapid correction of blood pressure and blood transfusions may be helpful in the treatment of patients who develop ION after surgery.

Optic disc structure and shock-induced anterior ischemic optic neuropathy

PURPOSE

To describe a patient who developed unilateral shock-induced anterior ischemic optic neuropathy (SIAION) after gastrointestinal hemorrhage followed by presumed idiopathic nonarteritic anterior ischemic optic neuropathy (NAION) in the fellow eye.

DESIGN

Retrospective, observational case report and literature review.

METHODS

The case history of an 80-year-old man who developed SIAION, followed by NAION in the fellow eye, was reviewed. All previously reported cases of SIAION were reviewed.

MAIN OUTCOME MEASURES

Neuro-ophthalmic examination, including visual acuity, funduscopy, and automated perimetry.

RESULTS

An 80-year-old man, with a history of gastrointestinal bleeding from a duodenal ulcer, was hospitalized and received four units of packed red blood cells after he was found to be severely anemic (hemoglobin 6.7 g/dl). Three days later he complained of loss of vision of the right eye. Neuro-ophthalmic examination 2 weeks later disclosed a visual acuity of counting fingers at 6 inches in the right eye and 20/40 in the left eye, with a right relative afferent pupillary defect and a superior altitudinal visual field defect. Funduscopy revealed optic disc edema with a temporal parapapillary hemorrhage in the right eye and a small optic disc, with no cup, in the left eye. A diagnosis of SIAION secondary to anemia was made. Six weeks later he developed a new inferior altitudinal visual field defect in the left eye and diffuse optic disc swelling. He had no signs or symptoms of giant cell arteritis or polymyalgia rheumatica, his hemoglobin at this time was 11.9 g/dl, and the Westergren erythrocyte sedimentation rate was 6 mm/hour.

CONCLUSIONS

Our patient developed optic disc swelling of the right eye after an episode of gastrointestinal hemorrhage (SIAION). The disc swelling in the left eye occurred 8 weeks later, when his hemoglobin had increased to 11.9 g/dl. The timing of the ischemic optic neuropathies suggests that the acute anemia led to involvement of the first but not the second eye. The configuration of the optic disc may have predisposed not only to the second event (NAION) but also to the first episode (SIAION).

Anterior ischemic optic neuropathy in children: case reports and review of the literature

Anterior ischemic optic neuropathy, infarction of the optic nerve head owing to inadequate perfusion through the posterior ciliary arteries, is a common cause of visual loss in adults but is rarely reported in children, in part because the diagnosis is overlooked. We report two cases of young children undergoing chronic peritoneal dialysis, who suffered bilateral visual loss from anterior ischemic optic neuropathy. Predisposing local anatomic and multiple systemic factors included a small optic nerve head with little cupping, possible intraocular hypertension, and systemic hypotension, hypovolemia, and anemia. The literature on anterior ischemic optic neuropathy is reviewed.

Blindness as a complication of Le Fort I osteotomy for maxillary distraction

High Le Fort I osteotomy and maxillary distraction has become an accepted method for the treatment of maxillary retrusion in children and teenagers with cleft lip and palate or craniofacial anomalies. This procedure effectively corrects the dentofacial deformity in these patients. No major surgical morbidity has been reported. During the past 4 years, 94 cleft patients with maxillary hypoplasia received Le Fort I osteotomy and distraction osteogenesis at the authors' center. Two of them developed blindness after this operation. The first case was a girl with bilateral cleft lip and palate with median facial dysplasia. She received high Le Fort I osteotomy at age 12 years 4 months to correct maxillary retrusion. Right eye swelling and ecchymosis was found after surgery. The patient complained of vision loss in that eye 2 days later. Computed tomography showed subarachnoid hemorrhage and skull base hematoma. There were no atypical fractures in the orbit, pterygoid plates, sphenoid bone, and skull base. Angiogram revealed left ophthalmic and basilar artery aneurysm. The second case was a 12-year-old boy with left cleft lip and palate. He received Le Fort I osteotomy to correct maxillary retrusion. During surgery, abnormal pupil dilatation was found after the osteotomy and down-fracture of maxilla. Emergent computed tomography found no hemorrhage or atypical fractures. Examination revealed complete left optic neuropathy and partial right abducens nerve palsy with mydriasis. Magnetic resonance imaging, magnetic resonance angiography, and repeated computed tomography revealed no sign of orbital injury, vascular problem, or abnormal fractures. The cause of blindness was unknown. In both cases, a steroid was used. Maxillary distraction was continued. Recovery of meaningful visual sense did not occur after 3 and 2 years' follow-up, respectively. A review of the literature revealed five other patients who suffered from visual loss after Le Fort I osteotomy. Inadvertent skull base fractures were identified in two cases, but a cause for the blindness was not known in the others. Induced hypotension and indirect trauma may be responsible for the optic nerve injury. In none of the cases was meaningful visual sense recovered, although high-dose steroids were given. In conclusion, a total of seven cases developed blindness after Le Fort I osteotomy. Once blindness develops, the prognosis is poor. High Le Fort I osteotomy should be performed with extreme care, and perhaps the informed consent should include visual loss as a complication of the procedure.

Optic neuropathy in uremia: an interdisciplinary emergency

Optic neuropathy in uremia is rare. Although the consequences of optic neuropathy-blindness or substantial loss of vision-are devastating, only a few cases have been reported by way of single case reports and case series studies. The reported patients are heterogeneous with regard to the cause of neuropathy. We report the case of a patient with uremic optic neuropathy and summarize the other cases reported in the literature so far. Based on the data available from these reports, we propose a classification system, which includes nonischemic neurotoxic uremic optic neuropathy; ischemic optic neuropathy, more specifically anterior ischemic optic neuropathy; and optic neuropathy as a result of drug side effects, benign intracranial hypertension, and optic neuritis. The immediate institution of dialysis and corticosteroid therapy and correction of anemia and relative hypotension can optimize the chances of visual recovery for these patients. Close collaboration among nephrologists, ophthalmologists, and neurologists is important in this interdisciplinary emergency.

Liposuction and ischemic optic neuropathy. Case report and review of literature

Ischemic optic neuropathy occurred in a patient following liposuction. Perioperative anemia and hypotension may be the cause of this complication. Correction of anemia with transfusion improved the hemoglobin and hematocrit but the right eye remained blind. Liposuction should be added to the list of the surgical procedures that may produce ischemic optic neuropathy as an isolated complication.

Anterior ischemic optic neuropathy: a complication after systemic inflammatory response syndrome

BACKGROUND

Patients are surviving previously fatal injuries. Unique morbidities are occurring in these survivors. Anterior ischemic optic neuropathy represents a previously unrecognized cause of blindness in the trauma victim. We hypothesize that this phenomenon is caused by unique characteristics of optic edema/ pressure or decreased blood flow associated with massive resuscitation.

METHODS

Between November of 1991 and August of 1998, there were 18,199 admissions to our trauma center. Of this group, 350 patients required massive volume resuscitation (>20 liters infused over first 24 hours). Patients having closed head injuries, facial fractures or direct orbital trauma were excluded from study. The following variables were studied: demographics, injury severity (Injury Severity Score, highest lactate, worst base deficit, and lowest pH) crystalloid and transfusion requirements, ventilator requirements (PEEP) RESULTS: Of the 350 patients with massive resuscitation, 9 patients were diagnosed with anterior ischemic optic neuropathy (2.6%). Of these, seven patients required celiotomy (78%). Six of the seven celiotomy patients had damage control celiotomies and abdominal compartment syndrome (86%). One patient had a repair of a subclavian artery; one had a complex acetabular repair. Blindness was unilateral in five patients and bilateral in four. All nine patients had evidence of global hypoperfusion, systemic inflammatory response, massive resuscitation, and high ventilatory support; one patient required cardiopulmonary resuscitation.

CONCLUSION

Prone positioning is known to be associated with an increased intraocular pressure. We postulate that the combination of massive resuscitation and prone positioning will increase the incidence of anterior ischemic optic neuropathy. As such, we recommend that prone positioning for adult respiratory distress syndrome be reserved for only those patients at risk of death.