Ischemic Optic Neuropathy Following Spine Surgery

Case Control Analysis and Systematic Review of the Literature

Anshit Goyal, MBBS; Mohamed Elminawy, MBBCh; Mohammed Ali Alvi, MBBS; Timothy R. Long, MD; John J. Chen, MD, PhD; Elizabeth Bradley, MD; Brett A. Freedman, MD; Mohamad Bydon, MD

Disclosures

Spine. 2019;44(15):1087-1096. 

In This Article

Abstract and Introduction

Abstract

Study Design: Case–control analysis and systematic literature review.

Objective: To illustrate the prognosis and perioperative risk factors associated with this condition.

Summary of Background Data: Ischemic optic neuropathy (ION) is the most common pathological diagnosis underlying postoperative vision loss. It comes in two primary forms—anterior (AION)—affecting the optic disc or posterior (PION) affecting the optic nerve proximal to the disc. Spine surgery remains one of the largest sources of acute perioperative visual loss.

Methods: We performed a 1:4 case–control analysis (by age and year of surgery) for patients with ION and those who didn't develop ION following spine surgery at our institution. A systematic literature search of Medline, Embase, Scopus from inception to September 2017 as also performed.

Results: We identified 12 cases from our institution. Comparison to 48 matched controls revealed fusion, higher number of operative levels, blood loss, and change in hemoglobin, hematocrit to be significantly associated with ION. Majority were diagnosed with PION (83%, 10/12) and had bilateral presentation (75%, 9/12). Only 30% patients (3/10) demonstrated improvement in visual acuity while the rest remained either unchanged (40%, 4/10) or worsened (20%, 2/10) at last follow-up. Literature review identified 182 cases from 42 studies. Posterior ischemic optic neuropathy (PION) was found in 58.7% (114/194) of cases, anterior ischemic optic neuropathy (AION) in 17% (33/19) and unspecified ION in 24% (47/194). PION was associated with higher odds of severe visual deficit at immediate presentation (odds ratio [OR]: 6.45, confidence interval [CI]: 1.04–54.3, P = 0.04) and last follow-up.

Conclusion: PION is the most common cause of vision loss following spine surgery and causes more severe visual deficits compared with AION. Prone spine surgery especially multi-level fusions with longer operative time, higher blood loss, and intraoperative hypotension are most associated with the development of this devastating complication.

Level of Evidence: 3

Introduction

Perioperative vision loss (POVL) is a rare event with devastating consequences in regards to quality of life. Despite an estimated incidence as low as 0.001% to 0.08%,[1] a substantial number of cases have been reported in the literature.[1–3] A variety of causative pathologies have associated with perioperative vision loss including, but not limited to, ischemic optic neuropathy.

Ischemic optic neuropathy (ION) has been implicated as the most common pathological diagnosis underlying POVL.[3] Perioperative posterior ischemic optic neuropathy (PION) has been suggested to be more common than its anterior counterpart, anterior ischemic optic neuropathy (AION) which is characterized by optic disc edema. This is in large contrast to spontaneous ischemic optic neuropathy, where AION is much more common.[1]

While a wide range of non-ocular surgeries have been associated with perioperative ischemic optic neuropathy,[4–6] spine surgery has been cited frequently as one of the most common interventions, apart from cardiac surgery.[2,7,8] Vision impairment is often very severe and bilateral because of irreparable optic nerve damage, regardless of whether the injury occurs in the optic disc (AION) or retrobulbar (PION).[4,9]

Realizing the growing burden of these cases, the American Society of Anesthesiologists (ASA) has maintained a perioperative visual loss registry since July 1999 which serves as an important source of documentation of these cases.[2,10] Patients undergoing spine surgery have remained the largest group reported in this prospectively maintained registry.[10] However, a consensus definition of patient population at risk and understanding of prognosis has been largely elusive because of the lack of a large-scale consolidated review of the literature.

To address this gap in knowledge, we performed a systematic review of the literature supplemented with our institutional case series and case–control analysis for patients diagnosed with ischemic optic neuropathy following spine surgery.

Comments

3090D553-9492-4563-8681-AD288FA52ACE

processing....