Ischemic Optic Neuropathy Following Spine Surgery: Case Control Analysis and Systematic Review of the Literature

Postoperative Glaucoma Decompensation Following Spine Surgery: The Importance of Proper Patient Positioning

Transforaminal lumbar interbody fusion (TLIF) is a widely utilized surgical procedure for the treatment of degenerative lumbar spinal conditions, including lumbar disc herniations, spinal stenosis, and spondylolisthesis. One such rare and underreported complication is vision loss following spinal surgery. Postoperative vision loss (POVL) is an extremely uncommon complication, occurring in approximately 0.002% to 0.2% of all non-ocular surgeries, including spinal procedures. We presented a 70-year-old male with complaints of left-sided cruralgia, lumbar radicular pain (sciatica-type L5), and right-sided weakness who underwent L4-S1 TLIF and who reported complete vision loss in his left eye, accompanied by persistent tearing from the affected eye whenever he attempted to focus his vision. The patient's vision in the left eye, which had been stable and functional prior to surgery, was permanently affected by the intraoperative complication. At the three-month follow-up, ophthalmological assessments confirmed that the optic nerve damage was irreversible, and the patient's vision in the left eye remained completely blurred. Postoperative vision loss (POVL) is a rare but devastating complication associated with various types of surgeries, including spinal procedures like transforaminal lumbar interbody fusion (TLIF). The present case of a 70-year-old patient developing permanent vision loss in his left eye due to glaucoma decompensation after TLIF underscores the importance of proper intraoperative positioning, especially in patients with pre-existing ocular conditions.

Visual Loss after Scoliosis Surgery: What Do Surgeons and Patients Need to Know? Three Case Reports

Visual deficit after spinal surgery is rare but tragic. The main causes include external eye injury, cortical blindness, central retinal artery occlusion, and ischemic optic neuropathy. In scoliosis surgery, this complication potentially arises from prolonged surgical time, high blood loss, prone position, hydroelectrolytic imbalance, and cerebrospinal fluid loss. In 849 scoliosis correction surgeries, 3 patients developed postoperative visual deficits: 2 achieved complete visual acuity recovery, but 1 remained with partial sequelae. There are four causes of postoperative amaurosis: ischemic optic neuropathy, central retinal artery occlusion, external eye injury, and cortical blindness. Since the prevention of this complication cannot be assured, it is essential to explain the risk of visual deficits to patients undergoing scoliosis surgery, who must sign the informed consent form. Visual loss after spinal surgery for scoliosis correction is a rare but severe and, sometimes, irreversible complication. The surgical team must know about this possibility in order to adopt preventive measures and reduce its incidence.

Perioperative Vision Loss Following Prone Spine Surgery: A Case-Control Study

PURPOSE

Perioperative vision loss (POVL) is a rare and devastating complication following prone spine surgery. Due to the rare nature of this complication, there is limited research available about patient and surgical risk factors that increase the risk of POVL. The objective of this study was to investigate associated risk factors for POVL with use of the National Surgical Quality Improvement Program (NSQIP) database.

DESIGN

This study used a case-control secondary data analysis methodology that included five cases of POVL and 250 controls from the American College of Surgeons National Surgical Quality Improvement Program database who all underwent prone spine surgery between 2010 and 2020.

METHODS

Each POVL case was matched to 50 randomly selected controls (n = 250) based on type and year of surgery. Demographics and variables of interest were compared among the POVL cases, among POVL cases and the aggregate control group (n = 250), and POVL cases against their matched control group. Univariate and multivariate conditional logistic regression were then used to estimate the odds of developing POVL in relation to potential patient and surgical risk factors.

FINDINGS

When POVL cases were compared to the 250 control cases using univariate analysis, patients who developed POVL were more likely to have received a blood transfusion within 72 hours of surgery (P < .0001). and have longer operative times (odds ratio = 1.01, 95% CI [1.003, 1.017], P = .003).

CONCLUSIONS

Two surgical risk factors were determined to be statistically significant, including the need for perioperative blood transfusion and prolonged operative time. These findings support previous research on POVL which often identified blood loss and prolonged operative times as surgical risk factors. The narrow patient population used in this project may have limited the ability to perform a more robust study on POVL. Therefore, further research on POVL using the National Surgical Quality Improvement Program database is strongly encouraged.

The prone position in COVID-19 impacts the thickness of peripapillary retinal nerve fiber layers and macular ganglion cell layers

The prone position reduces mortality in severe cases of COVID-19 with acute respiratory distress syndrome. However, visual loss and changes to the peripapillary retinal nerve fiber layer (p-RNFL) and the macular ganglion cell layer and inner plexiform layer (m-GCIPL) have occurred in patients undergoing surgery in the prone position. Moreover, COVID-19-related eye problems have been reported. This study compared the p-RNFL and m-GCIPL thicknesses of COVID-19 patients who were placed in the prone position with patients who were not. This prospective longitudinal and case-control study investigated 15 COVID-19 patients placed in the prone position (the "Prone Group"), 23 COVID-19 patients not in the prone position (the "Non-Prone Group"), and 23 healthy, non-COVID individuals without ocular disease or systemic conditions (the "Control Group"). The p-RNFL and m-GCIPL thicknesses of the COVID-19 patients were measured at 1, 3, and 6 months and compared within and between groups. The result showed that the Prone and Non-Prone Groups had no significant differences in their p-RNFL thicknesses at the 3 follow-ups. However, the m-GCIPL analysis revealed significant differences in the inferior sector of the Non-Prone Group between months 1 and 3 (mean difference, 0.74 μm; P = 0.009). The p-RNFL analysis showed a significantly greater thickness at 6 months for the superior sector of the Non-Prone Group (131.61 ± 12.08 μm) than for the Prone Group (118.87 ± 18.21 μm; P = 0.039). The m-GCIPL analysis revealed that the inferior sector was significantly thinner in the Non-Prone Group than in the Control Group (at 1 month 80.57 ± 4.60 versus 83.87 ± 5.43 μm; P = 0.031 and at 6 months 80.48 ± 3.96 versus 83.87 ± 5.43 μm; P = 0.044). In conclusion, the prone position in COVID-19 patients can lead to early loss of p-RNFL thickness due to rising intraocular pressure, which is independent of the timing of prone positioning. Consequently, there is no increase in COVID-19 patients' morbidity burden.

Cortical blindness after percutaneous vertebroplasty: a case report and comprehensive review of the literature

OBJECTIVE

Many complications but cortical blindness after percutaneous vertebroplasty has been rarely reported. Here, we describe a case who developed cortical blindness after percutaneous vertebroplasty. We also reviewed the literature to find the possible causes of this complication and its treatment.

METHODS

Case report and literature review.

RESULTS

A 71-year-old woman experienced cortical blindness after percutaneous vertebroplast. She developed dizziness, nausea, sweating, blood pressure changes, and vision loss during the procedure. MRI confirmed bilateral cerebral infarctions. The patient recovered with conservative treatment.

CONCLUSIONS

Percutaneous vertebroplasty, though helpful, carries a rare risk of cortical blindness. Surgeon awareness is crucial for informing patients of this potential complication.

The effect of restrictive vs. liberal fluid protocols on ocular parameters in patients undergoing prone spine surgery: a randomized controlled trial

BACKGROUND

Elevated intraocular pressure (IOP) and optic nerve edema occurring during prone surgeries may cause ocular and optic nerve ischaemia injury. We hypothesized that a liberal fluid protocol might further increase IOP and optic nerve sheath diameter (ONSD) than a restrictive fluid protocol for patients in the prone position.

METHODS

A single-centre, prospective and randomized trial was conducted. Patients were randomly allocated into 2 groups: the liberal fluid infusion group, in which repeated bolus doses of Ringer's lactate solution were given to maintain pulse pressure variation (PPV) within 6~9%, and the restrictive fluid infusion group, where PPV was maintained within 13-16%. IOP and ONSD were measured in both eyes at 10min after the anaesthesia induction in the supine position, 10min after the prone position placement, and 1h and 2h since the prone position was placed, at the conclusion of surgery, and returned to the supine position.

RESULTS

A total of 97 patients were recruited and completed the study. IOP increased significantly from 12±3mmHg in the supine position to 31±5 mmHg (p<0.001) at the end of surgery in the liberal fluid infusion group and from 12±2 to 28±4 mmHg (p<0.001) in the restrictive fluid infusion group. There was a statistically significant difference in the change of IOP over time between the two groups (p=0.019). ONSD increased significantly from 5.3±0.3mm in the supine position to 5.5±0.3mm (p<0.001) at the end of surgery in both groups (both p<0.001). There was no statistically significant difference in the change of ONSD over time between the two groups (p>0.05).

CONCLUSIONS

Compared to the restrictive fluid protocol, the liberal fluid protocol increased IOP but not ONSD in patients undergoing prone spine surgery.

TRIAL REGISTRATION

The study was registered in ClinicalTrials.gov ( https://clinicaltrials.gov ) prior to patient enrollment, ID: NCT03890510, on March 26, 2019. The principal investigator was Xiao-Yu Yang.

Albumin Use in Brain-injured and Neurosurgical Patients: Concepts, Indications, and Controversies

Human albumin has been used extensively for decades as a nonwhole blood plasma replacement fluid in the perioperative and critical care setting. Its potential advantages as a highly effective volume expander must be weighed, however, against its potential harm for patients in the context of various neurological states and for various neurosurgical interventions. This narrative review explores the physiological considerations of intravenous human albumin as a replacement fluid and examines the extant clinical evidence for and against its use within the various facets of modern neuroanesthesia and neurocritical care practice.

Proning related bilateral anterior ischaemic optic neuropathy in a patient with COVID-19 related acute respiratory distress syndrome

BACKGROUND

Non-arteritic ischaemic optic neuropathy (NAION) is a rare but harmful complication of prone positioning. Prone mechanical ventilation is a therapeutic strategy which has been used extensively during the COVID-19 pandemic to treat acutely hypoxemic patients with COVID-19 related acute respiratory distress syndrome (ARDS). Though a small number of cases of unilateral NAION have been reported in patients testing positive for the SARS-CoV-2 virus, we describe what is to our knowledge, the first reported case of bilateral NAION occurring in a patient proned extensively for the treatment of COVID-19 related ARDS. We consider the potential aetiological factors leading to NAION after prone mechanical ventilation in patients with COVID-19 and suggest strategies to protect against its development.

CASE PRESENTATION

We report a case of severe, irreversible, visual impairment secondary to bilateral anterior ION in a fifty-five-year-old male who underwent eight episodes of prone mechanical ventilation to treat COVID-19 related ARDS. Once weaned from his sedation he reported bilateral painless vision loss, and bedside ophthalmological assessment identified a reduced visual acuity of 3/30 unaided in the left eye and counting fingers in the right. Dilated indirect ophthalmoscopy revealed inferotemporal optic disc oedema with splinter haemorrhages in the right eye and mild disc oedema, temporal pallor, and nerve fibre layer haemorrhages inferiorly in the left eye. Humphrey visual field 24 - 2 testing confirmed a severely constricted visual field with macular sparing on the right and depressed inferonasal vision with preserved peripheral vision on the left eye. OCT disc imaging shortly after diagnosis revealed bilateral disc swelling and flame haemorrhages in the right eye.

CONCLUSIONS

NAION is a devastating, but preventable complication of prone positioning, which may pose significant risk of vision loss in patients with COVID-19 related ARDS.

Bilateral Simultaneous Anterior Ischemic Optic Neuropathy following Total Knee Arthroplasty with Epidural Block

Ischemic optic neuropathy (ION) resulting in perioperative vision loss (POVL) is a rare occurrence following nonocular procedures. Bilateral simultaneous anterior ION (AION) is even rarer, and no cases have been reported after central neuraxial block. We report a case of bilateral simultaneous AION, confirmed by multimodal imaging, in a 66-year-old male patient who underwent total knee arthroplasty under epidural anesthesia in which episodes of hypotension-one intraoperatively and one late postoperatively-had occurred. Hypotension is the most common adverse effect to epidural block, and counseling about POVL should extend beyond general anesthesia to include those undergoing procedures with central neuraxial block.

Sudden painless loss of vision following spine surgery: lessons learnt in darkness

A 26-year-old male driver presented with a history of pain in the neck for the past 1 week following trauma due to a road traffic accident. The patient had no neurological deficit. He had type 1 diabetes and was on regular oral hypoglycemics. After radiological investigations, the patient was diagnosed to have traumatic AO Spine Classification type C translational injury involving anterolisthesis of C6 over C7. After a detailed preoperative assessment, the patient was taken up for surgery. The patient underwent posterior stabilisation with instrumentation from C5 to T2. On extubation from anaesthesia, he immediately complained of complete painless loss of this vision in his left eye. Ophthalmological investigations attributed the cause to be due to central retinal artery occlusion. The patient was discharged with reassurance on the 20th postoperative day with minimal improvement in his vision and at 6-month follow-up, his vision improved to 1/60 and was advised for close follow-up.

Ocular Complications in the Prone Position in the Critical Care Setting: The COVID-19 Pandemic

PURPOSE

Ocular complications are common in the critical care setting but are frequently missed due to the focus on life-saving organ support. The SARS-CoV-2 (COVID-19) pandemic has led to a surge in critical care capacity and prone positioning practices which may increase the risk of ocular complications. This article aims to review all ocular complications associated with prone positioning, with a focus on challenges posed by COVID-19.

MATERIALS AND METHODS

A literature review using keywords of "intensive care", "critical care", "eye care", "ocular disorders", "ophthalmic complications," "coronavirus", "COVID-19," "prone" and "proning" was performed using the electronic databases of PUBMED, EMBASE and CINAHL.

RESULTS

The effects of prone positioning on improving respiratory outcomes in critically unwell patients are well established; however, there is a lack of literature regarding the effects of prone positioning on ocular complications in the critical care setting. Sight-threatening ophthalmic disorders potentiated by proning include ocular surface disease, acute angle closure, ischemic optic neuropathy, orbital compartment syndrome and vascular occlusions.

CONCLUSIONS

COVID-19 patients may be more susceptible to ocular complications with increased proning practices and increasing demand on critical care staff. This review outlines these ocular complications with a focus on preventative and treatment measures to avoid devastating visual outcomes for the patient.

Neuroanesthesiology Update

This review is intended to provide a summary of the literature pertaining to the perioperative care of neurosurgical patients and patients with neurological diseases. General topics addressed in this review include general neurosurgical considerations, stroke, neurological monitoring, and perioperative disorders of cognitive function.

Cushing Syndrome: A Potential Risk of Bilateral Postoperative Ischemic Optic Neuropathy after Lumbar Fusion

This is a report of a 58-year-old female with Cushing syndrome who underwent posterior lumbar fusion and lost both her vision completely. She was diagnosed with posterior ischemic optic neuropathy. Cushingoid features such as buffalo hump and central obesity might have attributed in triggering posterior ischemic optic neuropathy. When laid prone for surgery, perioperative high abdominal pressure causes venous hypertension leading to increase amount of blood loss. To compensate, infusion of large quantities of intravenous fluids is necessary which leads to hemodilution which decreases ocular perfusion pressure. Hypercoagulability of Cushing syndrome is also potentially a risk factor of this condition which increases the incidence of venous thromboembolism. For there is no known effective treatment for posterior ischemic optic neuropathy, means to prevent this complication must be strategically reviewed. When performing long spine surgery on patient who has Cushing syndrome or cushingoid features, caution must be taken to avoid this devastating complication.