Ischemic Optic Neuropathy in Cardiac Surgery: Incidence and Risk Factors in the United States from the National Inpatient Sample 1998 to 2013

Validity of Administrative Coding for Nonarteritic Ischemic Optic Neuropathy

BACKGROUND

Administrative claims have been used to study the incidence and outcomes of nonarteritic ischemic optic neuropathy (NAION), but the validity of International Classification of Diseases (ICD)-10 codes for identifying NAION has not been examined.

METHODS

We identified patients at 3 academic centers who received ≥1 ICD-10 code for NAION in 2018. We abstracted the final diagnosis from clinical documentation and recorded the number of visits with an NAION diagnosis code. We calculated positive predictive value (PPV) for the overall sample and stratified by subspecialty and the number of diagnosis codes. For patients with ophthalmology or neuro-ophthalmology visit data, we recorded presenting symptoms, examination findings, and laboratory data and calculated PPV relative to case definitions of NAION that incorporated sudden onset of symptoms, optic disc edema, afferent pupillary defect, and other characteristics.

RESULTS

Among 161 patients, PPV for ≥1 ICD-10 code was 74.5% (95% CI: 67.2%-80.7%). PPV was similar when restricted to patients who had visited an ophthalmologist (75.8%, 95% CI: 68.4%-82.0%) but increased to 86.8% when restricted to those who had visited neuro-ophthalmologists (95% CI: 79.2%-91.9%). Of 113 patients with >1 ICD-10 code and complete examination data, 37 (32.7%) had documented sudden onset, optic disc swelling, and an afferent pupillary defect (95% CI: 24.7%-42.0%). Of the 76 patients who did not meet these criteria, 54 (71.0%) still received a final clinical diagnosis of NAION; for most (41/54, 75.9%), this discrepancy was due to lack of documented optic disc edema.

CONCLUSIONS

The validity of ICD-10 codes for NAION in administrative claims data is high, particularly when combined with provider specialty.

How far should I manage acute optic neuritis as an ophthalmologist? A United Kingdom perspective

Optic neuritis (ON) is an inflammation of or around the optic nerve, frequently caused by infectious or immune-mediated inflammatory disorders. In the UK, its strongest association is with Multiple Sclerosis (MS), though the combined prevalence of other associated infectious and immune-mediated inflammatory diseases (I-IMID) is similar to that of MS-ON. Prompt identification and understanding of ON's underlying cause informs tailored management and prognosis. Several IMIDs linked to ON, such as aquaporin-4 antibody-associated optic neuritis (AQP4-ON), myelin oligodendrocyte glycoprotein antibody-associated optic neuritis (MOG-ON), and neuro-sarcoidosis, show remarkable response to corticosteroid treatment. Therefore, urgent investigation and treatment are crucial in cases 'atypical' for MS-ON. Following the 1992 Optic Neuritis Treatment Trial, clinical practice has evolved, with short-course high-dose corticosteroids considered safe and effective for most people. Timely recognition of patients who could benefit is critical to avoid irreversible vision loss. This review provides a practical guide and a summary of evidence on the investigation and management of acute optic neuritis. It reflects the knowledge and limitations of current evidence, framed through the neuro-ophthalmic perspective of clinical practice at multiple UK academic centres.

[Perioperative visual loss : Rare, unknown, relevant?]

Perioperative visual loss (POVL) is a rare but severe complication following non-ophthalmological surgery under general anesthesia. A POVL can be caused by lesions in any part of the optical system. The predominant causes include corneal injuries and particularly ischemic damage. The symptoms of POVL substantially vary ranging from reduced vision to complete blindness. The risks involve factors related to the surgery as well as patient-specific factors. In general, the prognosis in cases of mechanical damage is better than for ischemic lesions. The treatment measures depend on the underlying pathomechanism and due to the limited evidence only a few treatment options are available. Therefore, preventive measures and meticulous documentation play a crucial role.

Incidence and Risk Factors for Postoperative Visual Loss after Cardiac Surgical Procedures: A Systematic Review

ABSTRACT

Postoperative visual loss (POVL) is an infrequent yet consequential complication that can follow cardiac surgical interventions. This systematic review aims to provide a comprehensive analysis of the incidence of POVL after cardiac surgery and to delineate the associated risk factors. A comprehensive search was conducted in major medical databases for relevant studies published up to September 2022. Eligible studies reporting on the incidence of POVL and identifying risk factors in patients undergoing cardiac surgery were included. Data extraction was performed independently by two reviewers. The pooled incidence rates and the identified risk factors were synthesized qualitatively. POVL after cardiac surgery has an overall incidence of 0.015%, that is, 15 cases per 100,000 cardiac surgical procedures. Risk factors for POVL include patient characteristics (advanced age, diabetes, hypertension, and preexisting ocular conditions), procedural factors (prolonged surgery duration, cardiopulmonary bypass time, and aortic cross-clamping), anesthetic considerations (hypotension, blood pressure fluctuations, and specific techniques), and postoperative complications (stroke, hypotension, and systemic hypoperfusion). Ischemic optic neuropathy (ION) is an uncommon complication, associated with factors like prolonged cardiopulmonary bypass, low hematocrit levels, excessive body weight gain, specific medications, hypothermia, anemia, raised intraocular pressure, and micro-embolization. Diabetic patients with severe postoperative anemia are at increased risk for anterior ischemic optic neuropathy (AION). Posterior ischemic optic neuropathy (PION) can occur with factors like hypertension, postoperative edema, prolonged mechanical ventilation, micro-embolization, inflammation, hemodilution, and hypothermia.While the overall incidence of POVL postcardiac surgery remains modest, its potential impact is substantial, necessitating meticulous consideration of modifiable risk factors. Notably, prolonged surgical duration, intraoperative hypotension, anemia, and reduced hematocrit levels remain salient contributors. Vigilance is indispensable to promptly detect this infrequent yet visually debilitating phenomenon in the context of postcardiac surgical care.

Perioperative Blindness in Spine Surgery: A Scoping Literature Review

Perioperative vision loss (POVL) is a devastating surgical complication that impacts both the recovery from surgery and quality of life, most commonly occurring after spine surgery. With rates of spine surgery dramatically increasing, the prevalence of POVL will increase proportionately. This scoping review aims to aggregate the literature pertinent to POVL in spine surgery and consolidate recommendations and preventative measures to reduce the risk of POVL. There are several causes of POVL, and the main contribution following spine surgery is ischemic optic neuropathy (ION). Vision loss often manifests immediately following surgery and is irreversible and severe. Diffusion weighted imaging has recently surfaced as a diagnostic tool to identify ION. There are no effective treatments; therefore, risk stratification for counseling and prevention are vital. Patients undergoing prone surgery of long duration and/or with significant expected blood loss are at greatest risk. Future research is necessary to develop effective treatments.

Early effects of cardiopulmonary bypass surgery on retinal nerve fiber layer and ganglion cell layer

PURPOSE

To determine the effects of cardiopulmonary bypass surgery on retinal nerve fiber layer, ganglion cell layer, and macula by optic coherens tomography (OCT).

METHOD

Sixty-six eyes of 33 patients aged between 44 and 74 who were indicated for cardiopulmonary bypass surgery in the cardiovascular surgery clinic were included in the study. Routine ophthalmologic examinations of all patients were performed before and 1 week after surgery. In addition, 3D(H) Macula+5 Line Cross 12 × 9 mm mod and Peripapilar 3D Disk 6 × 6 mm mod data were analyzed with OCT (Topcon, Triton Swept Source-OKT, Tokyo, Japan) device. Peripapillary total, superior, inferior retinal nerve fiber layer (RNFL), optic disc cavity volume, cup-to-disc ratio, macular ganglion cell layer (GCL), macular thickness were compared before and after surgery.

RESULTS

After cardiopulmonary bypass surgery, thickening was detected in the total RNFL (p<0.001), superior RNFL (p = 0.01) and inferior RNFL (p<0.001) layers. There was no change in the values of GCL, macular thickness, optic disc cupping volume, cup-to-disc ratio after surgery (p>0.05). There was a positive correlation (r = 0.392 p<0.05) between the patients' blood oxygen (PO2) values during bypass surgery with their post-surgical GCL+ values, and a negative correlation between optic disc cup volumes (r=-0.349 p<0.05).

CONCLUSION

RNFL thickening has been detected in patients undergoing cardiopulmonary bypass surgery. This thickening may occur secondary to ischemic edema that occurs during surgery. Considering the late complications of ischemic edema in the RNFL, oxygen levels should be kept at an optimum level during surgery and long-term ophthalmologic follow-ups should be performed.

Perioperative Ischemic Optic Neuropathy after Cardiac Surgery: Development and Validation of a Preoperative Risk Prediction Model

OBJECTIVE

Previous studies identified risk factors for ischemic optic neuropathy (ION) after cardiac surgery; however, there is no easy-to-use risk calculator for the physician to identify high-risk patients for ION before cardiac surgery. The authors sought to develop and validate a simple-to-use predictive model and calculator to assist with preoperative identification of risk and informed consent for this rare but serious complication.

DESIGN

Retrospective case-control study.

SETTING

Hospital discharge records.

PATIENTS

A total of 5,561,177 discharges in the National Inpatient Sample >18 years of age, with procedure codes for coronary artery bypass grafting, heart valve repair/replacement, or left ventricular assist device insertion.

INTERVENTIONS

All patients had undergone cardiac surgery.

MEASUREMENTS AND MAIN RESULTS

Known preoperative risk factors for ION after cardiac surgery were assessed to develop a risk score and prediction model. This model was validated internally using the split-sample method. There were 771 cases of ION among 5,561,177 patients in the National Inpatient Sample. The risk factors for ION used in the model were carotid artery stenosis, cataract, diabetic retinopathy, macular degeneration, glaucoma, male sex, and prior stroke; whereas uncomplicated diabetes decreased risk. With the internal validation, the predictive model had an area under the receiver operating characteristic curve of 0.66. A risk score cutoff ≥3 had 98.4% specificity.

CONCLUSIONS

This predictive model, based on previously identified preoperative factors, predicted risk of perioperative ION with a fair area under the receiver operating characteristic curve. This predictive model could enable screening to provide a more accurate risk assessment for ION, and consent process for cardiac surgery.

Perioperative Care of the Patient with Eye Pathologies Undergoing Nonocular Surgery

The authors reviewed perioperative ocular complications and implications of ocular diseases during nonocular surgeries. Exposure keratopathy, the most common perioperative eye injury, is preventable. Ischemic optic neuropathy, the leading cause of perioperative blindness, has well-defined risk factors. The incidence of ischemic optic neuropathy after spine fusion, but not cardiac surgery, has been decreasing. Central retinal artery occlusion during spine fusion surgery can be prevented by protecting eyes from compression. Perioperative acute angle closure glaucoma is a vision-threatening emergency that can be successfully treated by rapid reduction of elevated intraocular pressure. Differential diagnoses of visual dysfunction in the perioperative period and treatments are detailed. Although glaucoma is increasingly prevalent and often questions arise concerning perioperative anesthetic management, evidence-based recommendations to guide safe anesthesia care in patients with glaucoma are currently lacking. Patients with low vision present challenges to the anesthesia provider that are becoming more common as the population ages.

Factors Affecting Optic Nerve Damage in Le Fort III Osteotomy: A Retrospective Study

The causes of visual impairment following Le Fort osteotomy for syndromic craniosynostosis have not been completely elucidated. The authors investigated the potential causes and means of prevention of optic nerve damage, with particular emphasis on intraoperative blood transfusion volume and operating time. This retrospective study evaluated patients who underwent Le Fort III osteotomy for syndromic craniosynostosis between 2000 and 2020. Data on pupillary reflex, pupil size, operating time, blood transfusion, age at time of surgery, sex, and syndrome type were obtained from medical records. Univariate analysis and multivariate analysis with the level of statistical significance set at P<0.05. For the 86 patients included, the mean values of operating time, amount of blood transfusion based on body weight, amount of blood transfusion per body weight per hour, and age were 6.0 hours (range: 3.5-12.3 h), 30.5 mL/kg (range: 0-322 mL/kg), 5.14 mL/kg/h (range: 0-35.7 mL/kg/h), and 10.0 years (range: 4-38 y), respectively. Crouzon, Apert, and Pfeiffer syndromes were observed in 49, 29, and 8 patients, respectively. Abnormal pupillary findings were observed in 27 patients of whom 25 showed no abnormalities in subsequent visual function and 2 developed blindness. Abnormal pupillary findings correlated with the amount of blood transfused per body weight (P=0.0082) and amount of blood transfused per body weight per hour (P=0.0052). As demonstrated in this study, increased intraoperative bleeding and amount of blood transfused were associated with optic nerve damage, particularly during acute bleeding. Prompt inspection of the pupils following surgery is therefore warranted.

An Overview of Commonly Used Data Sources in Observational Research in Anesthesia

Anesthesia research using existing databases has drastically expanded over the last decade. The most commonly used data sources in multi-institutional observational research are administrative databases and clinical registries. These databases are powerful tools to address research questions that are difficult to answer with smaller samples or single-institution information. Given that observational database research has established itself as valuable field in anesthesiology, we systematically reviewed publications in 3 high-impact North American anesthesia journals in the past 5 years with the goal to characterize its scope. We identified a wide range of data sources used for anesthesia-related research. Research topics ranged widely spanning questions regarding optimal anesthesia type and analgesic protocols to outcomes and cost of care both on a national and a local level. Researchers should choose their data sources based on various factors such as the population encompassed by the database, ability of the data to adequately address the research question, budget, acceptable limitations, available data analytics resources, and pipeline of follow-up studies.

Mortality Among Hospitalized Individuals With Systemic Lupus Erythematosus in the US Between 2006 and 2016

OBJECTIVE

To evaluate time trends in mortality for hospitalized adults with systemic lupus erythematosus (SLE) compared to the general hospitalized population (GHP), and to identify factors associated with increased risk of death among hospitalized SLE patients.

METHODS

We used the National (Nationwide) Inpatient Sample to estimate all-cause mortality for adults discharged from community hospitals in the US between 2006 and 2016. Poisson regression models were used to estimate the risk of in-hospital death among all patients, including demographic characteristics, socioeconomic factors, comorbidity score, hospital region, SLE diagnosis, and race/ethnicity as covariates.

RESULTS

Among 340,467,049 hospitalizations analyzed, 1,903,279 had a discharge diagnosis of SLE. In adjusted analysis, the risk of inpatient death decreased among hospitalizations for patients with SLE from 2.2% to 1.5% (P < 0.001) between 2006 and 2016. All of the decrease in SLE mortality occurred between 2006 and 2008; after 2008, mortality stabilized at a rate statistically similar to the GHP. Hospitalizations for Black, Hispanic, and Asian/Pacific Islander patients with SLE were more likely to end in death compared to hospitalizations for either White patients with SLE or individuals of the same non-White race/ethnicity without SLE.

CONCLUSION

In the largest study of in-hospital SLE mortality published to date, we found significant improvements in mortality for hospitalized patients with SLE in the US from 2006 until 2008, after which mortality stabilized at a level similar to that of the GHP. Our results also demonstrate a persistently high mortality burden among Black and Hispanic patients with SLE in the US and contribute new data revealing high mortality among Asian/Pacific Islander patients with SLE.

Predictive model of ischemic optic neuropathy in spinal fusion surgery using a longitudinal medical claims database

BACKGROUND CONTEXT

Perioperative ischemic optic neuropathy (ION) is a devastating complication of spinal fusion surgery.

PURPOSE

To develop predictive models of this blinding condition using a longitudinal medical administrative claims database, which provides temporal sequence of perioperative ischemic optic neuropathy and potential risk factors.

DESIGN

Nested case control study.

PATIENT SAMPLE

Participants in Cliniformatics Data Mart medical claims database (2007-2017) with hospitalization involving lumbar or thoracic spinal fusion surgery and no history of ION.

OUTCOME MEASURES

Perioperative ION (or not) during hospitalization for lumbar or thoracic spinal fusion surgery.

METHODS

Sixty-five ION cases and 106,871 controls were identified. Matched controls (n=211) were selected based on year of surgery and zip code. Chronic and perioperative variables were assigned based on medical claims codes. Least absolute shrinkage and selection (LASSO) penalized conditional logistic regression with 10-fold cross validation was used to select variables for the optimal predictive model from the subset of variables with p<.15 between cases and matched controls (unadjusted conditional logistic regression). Receiver operating characteristic (ROC) curves were generated for the strata-independent matched and full sample.

RESULTS

The predictive model included age 57-65 years, male gender, diabetes with and without complications, chronic anemia, hypertension, heart failure, carotid stenosis, perioperative hemorrhage and perioperative organ damage. Area under ROC curve was 0.75 (95% confidence interval [CI]: 0.68, 0.82) for the matched sample and 0.72 (95% CI: 0.66, 0.78) for the full sample.

CONCLUSIONS

This predictive model for ION in spine fusion considering chronic conditions and perioperative conditions is unique to date in its use of longitudinal medical claims data, inclusion of International Classification of Disease-10 codes and study of ophthalmic conditions as risk factors. Similar to other studies of this condition the multivariable model included age, male gender, perioperative organ damage and perioperative hemorrhage. Hypertension, chronic anemia and carotid artery stenosis were new predictive factors identified by this study.

Ocular complications of perioperative anesthesia: a review

Ocular complications associated with anesthesia in ocular and non-ocular surgeries are rare adverse events which may present with clinical presentations vacillating between easily treatable corneal abrasions to more serious complication such as irreversible bilateral vision loss. In this review, we outline the different techniques of anesthetic delivery in ocular surgeries and highlight the incidence and etiologies of associated injuries. The changes in vision in non-ocular surgeries are mistaken for residual sedation or anesthetics, therefore require high clinical suspicion on part of the treating ophthalmologists, to ensure early diagnosis, adequate and swift management especially in surgeries such as cardiac, spine, head and neck, and some orthopedic procedures, that have a comparatively higher incidence of ocular complications. In this article, we review the literature for reports on the clinical incidence of different ocular complications associated with anesthesia in non-ocular surgeries and outline the current understanding of pathophysiological processes associated with these adverse events.

Changes in intraocular pressure during coronary artery bypass graft surgery: an observational study

Background

In this study, the effects of pulsatile and non-pulsatile on-pump Coronary Artery Bypass Graft surgery (CABG) and off-pump CABG techniques on the intraocular pressure were investigated.

Methods

Forty-five patients who planned to elective coronary artery bypass surgery with on-pump pulsatile (n = 15), non-pulsatile (n = 15), or off-pump (n = 15) were included. Intraocular Pressure (IOP) measurements were performed on both eyes at nine time-points: 1) Before the operation, 2) After anesthesia induction, 3) 3 minutes after heparin administration Left Internal Mammary Artery (LIMA) harvesting, 4) End of the first anastomosis, 5) End of LIMA anastomosis, 6) 3 minutes after protamine administration, 7) End of the operation, and 8) Second hour in Intensive Care Unit (ICU), 9) Fifth hour in ICU. Mean Arterial Pressure (MAP) and Central Venous Pressure (CVP) were also recorded at the same time points as IOP.

Results

In Cardiopulmonary Bypass (CPB) groups (pulsatile or non-pulsatile CPB) with the beginning of CPB, there were significant decreases in IOP values when compared to baseline (p = 0.012). This decrease was more prominent in the non-pulsatile group when compared to the pulsatile group (T₄ IOP values: pulsatile, 9.7 ± 2.6; non-pulsatile, 6.8 ± 1.9; p = 0.002; T₅ IOP values: pulsatile, 9.5 ± 1.9; non-pulsatile, 6.7 ± 2.1; p = 0.004). At the end of the surgery (T₇), IOP values returned to the baseline and stayed stable at the remaining time-points. In-off pump group, IOP values significantly increased with a head-down position (T₄ IOP values: off-pump surgery, 19.7 ± 5.2; p = 0.015). IOP values remained high until the normalization of head-down position (T₆) and stayed stable through the rest of all remaining time-points.

Conclusion

During cardiac surgery regardless of the technique (on-pump CABG, off-pump CABG), intraocular pressures remain in the normal ranges. It should be kept in mind that patients should be avoided from long and extreme Trendelenburg position, low CVP, and MAP levels during cardiac surgery to prevent eye-related complications.

Angiotensin II for Critically Ill Patients With Shock After Heart Transplant

Patients undergoing heart transplant are at high risk for vasodilatory shock in the postoperative period, due to a combination of vascular dysfunction from end-stage heart failure and inflammatory response to cardiopulmonary bypass and, increasingly, long-term exposure to nonpulsatile blood flow in those who have received a left ventricular assist device as a bridge to transplant. Patients who have this vasoplegic syndrome, which may be refractory to traditional agents used in the treatment of shock, are vulnerable to organ dysfunction and death. Angiotensin II (ANG-2) is of increasing interest as an adjunct to traditional therapy, both for improvement in blood pressure and for sparing the use of high-dose catecholamine vasopressors. This case series describes the use of ANG-2 in 4 clinical scenarios for the treatment of shock due to heart transplant surgery, supporting its use in this role and justifying further prospective studies to clarify the appropriate place for ANG-2 in the hierarchy of adjunctive therapies.

Incidence of Ischemic Optic Neuropathy After Cardiopulmonary Bypass: 20-Year Experience

OBJECTIVE

This study evaluated the incidence and risk factors for ischemic optic neuropathy (ION) as a complication of cardiac surgery requiring cardiopulmonary bypass (CPB).

DESIGN

Retrospective chart review of prospectively collected data at a tertiary care center.

SETTING

Single tertiary academic referral center.

PARTICIPANTS

This study comprised 44,568 cardiac surgery patients who underwent CPB between January 1, 1995, and January 5, 2017, using the Society of Thoracic Surgeons database and cross-matching it with International Classification of Diseases codes for visual changes.

INTERVENTIONS

None; this was a retrospective chart review.

MEASUREMENTS AND MAIN RESULTS

Six patients initially were identified as experiencing visual changes. Only 1 patient from 44,568 cardiac surgeries with CPB between January 1, 1995, and January 5, 2017, experienced ION, for an incidence 0.22 per 10,000. Because only 1 patient experienced ION, the authors were unable to determine risk factors for this complication; however, the nadir perioperative hemoglobin in the affected patient was 7.3 g/dL (postoperative).

CONCLUSION

The incidence of ION decreased from 6 per 10,000 in the authors' previous study from 1976-1994 to 0.22 per 10,000 in the present study. Because of the low incidence of this dreaded complication, the authors were not able to identify risk factors for ION. Practice improvements (eg, transition to membrane oxygenators, blood transfusion guidelines, less- invasive surgical options for high-risk patients) during the time between the authors' studies likely affected the incidence reduction.

Big Data Research in Neuro-Ophthalmology: Promises and Pitfalls

BACKGROUND

Big data clinical research involves application of large data sets to the study of disease. It is of interest to neuro-ophthalmologists but also may be a challenge because of the relative rarity of many of the diseases treated.

EVIDENCE ACQUISITION

Evidence for this review was gathered from the authors' experiences performing analysis of large data sets and review of the literature.

RESULTS

Big data sets are heterogeneous, and include prospective surveys, medical administrative and claims data and registries compiled from medical records. High-quality studies must pay careful attention to aspects of data set selection, including potential bias, and data management issues, such as missing data, variable definition, and statistical modeling to generate appropriate conclusions. There are many studies of neuro-ophthalmic diseases that use big data approaches.

CONCLUSIONS

Big data clinical research studies complement other research methodologies to advance our understanding of human disease. A rigorous and careful approach to data set selection, data management, data analysis, and data interpretation characterizes high-quality studies.

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.

Validity of International Classification of Diseases Codes for Identifying Neuro-Ophthalmic Disease in Large Data Sets: A Systematic Review

BACKGROUND

Administrative health claims data have been used for research in neuro-ophthalmology, but the validity of International Classification of Diseases (ICD) codes for identifying neuro-ophthalmic conditions is unclear.

EVIDENCE ACQUISITION

We performed a systematic literature review to assess the validity of administrative claims data for identifying patients with neuro-ophthalmic disorders. Two reviewers independently reviewed all eligible full-length articles and used a standardized abstraction form to identify ICD code-based definitions for 9 neuro-ophthalmic conditions and their sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). A quality assessment of eligible studies was also performed.

RESULTS

Eleven articles that met criteria for inclusion are as follows: 3 studies of idiopathic intracranial hypertension (PPV 54%-91% and NPV 74%-85%), 2 studies of giant cell arteritis (sensitivity 30%-96% and PPV 94%), 3 studies of optic neuritis (sensitivity 76%-99%, specificity 83%-100%, PPV 25%-100%, and NPV 98%-100%), 1 study of neuromyelitis optica (sensitivity 60%, specificity 100%, PPV 43%-100%, and NPV 98%-100%), 1 study of ocular motor cranial neuropathies (PPV 98%-99%), and 2 studies of myasthenia gravis (sensitivity 53%-97%, specificity 99%-100%, PPV 5%-90%, and NPV 100%). No studies met eligibility criteria for nonarteritic ischemic optic neuropathy, thyroid eye disease, and blepharospasm. Approximately 45.5% provided only one measure of diagnostic accuracy. Complete information about the validation cohorts, inclusion/exclusion criteria, data collection methods, and expertise of those reviewing charts for diagnostic accuracy was missing in 90.9%, 72.7%, 81.8%, and 36.4% of studies, respectively.

CONCLUSIONS

Few studies have reported the validity of ICD codes for neuro-ophthalmic conditions. The range of diagnostic accuracy for some disorders and study quality varied widely. This should be taken into consideration when interpreting studies of neuro-ophthalmic conditions using administrative claims data.

Predicting Risk of Perioperative Ischemic Optic Neuropathy in Spine Fusion Surgery: A Cohort Study Using the National Inpatient Sample

BACKGROUND

Ischemic optic neuropathy (ION) is a rare complication of anesthesia and surgery that causes vision loss in spine fusion. We sought to develop a predictive model based on known preoperative risk factors for perioperative ION to guide patient and physician preoperative decision-making.

METHODS

In the National Inpatient Sample (NIS) for 1998-2012, discharges for posterior thoracic, lumbar, and sacral spine fusion were identified and classified by ION status. Variables were selected without weighting via variable clustering using Principal Component Analysis of Mixed Data (PCA-MIX). Hierarchical clustering with 4 clusters was performed, and the variable with largest squared loading in each cluster was chosen. By splitting our sample into a training and testing data set, we developed and internally validated a predictive model. The final model using variables known preoperatively was constructed to allow determination of relative and absolute risk of developing perioperative ION and was tested for calibration and discrimination.

RESULTS

The final predictive model based on hierarchical clustering contained 3 preoperative factors, age, male or female sex, and the presence of obstructive sleep apnea (OSA). The predictive model based on these factors had an area under the receiver operating characteristic curve (AUC) of 0.65 and good calibration. A score cutoff of >1 had 100% sensitivity, while score of 3 had 96.5% specificity. The highest estimated absolute risk (844.5/million) and relative risk of ION (46.40) was for a man, age 40-64 years, with OSA.

CONCLUSIONS

The predictive model could enable screening for patients at higher risk of ION to provide more accurate risk assessment and surgical and anesthetic planning for perioperative ION in spine fusion.

[Acute ischemic optic nerve disease: Pathophysiology, clinical features and management (French translation of the article)]

Ischemic optic neuropathies are among the leading causes of severe visual acuity loss in people over 50 years of age. They constitute a set of various entities that are clinically, etiologically and therapeutically different. Anatomically, it is necessary to distinguish anterior and posterior forms. From an etiological point of view, the diagnosis of the arteritic form due to giant cell arteritis requires emergent management to prevent blindness and even death in the absence of prompt corticosteroid treatment. When this diagnosis has been ruled out with certainty, non-arteritic ischemic optic neuropathies represent a vast etiological context that in the majority of cases involves a local predisposing factor (small optic nerves, disc drusen) with a precipitating factor (severe hypotension, general anesthesia or dialysis) in a context of vascular disease (sleep apnea syndrome, hypertension, diabetes, etc.). In the absence of specific available treatment, it is the responsibility of the clinician to identify the risk factors involved, in order to reduce the risk of contralateral recurrence that may occur even several years later. Due to their complexity, these pathologies are the subject of debates regarding both the pathophysiological and therapeutic perspectives; this review aims to provide a synthesis of validated knowledge while discussing controversial data.

BILATERAL PARACENTRAL ACUTE MIDDLE MACULOPATHY AFTER CARDIOPULMONARY BYPASS

PURPOSE

To report the first two observations of bilateral paracentral acute middle maculopathy in the early postoperative period after cardiopulmonary bypass procedures.

METHODS

Comprehensive ophthalmic examinations were performed, including best-corrected visual acuity, Humphrey visual field testing, dilated fundus examination, and optical coherence tomography.

RESULTS

Two patients complained of unilateral vision loss after cardiac surgery involving cardiopulmonary bypass. Unilateral optic disc edema consistent with ischemic optic neuropathy was observed in the symptomatic eye of each patient, whereas scattered cotton-wool spots were identified bilaterally. In addition, optical coherence tomography imaging revealed bilateral paracentral acute middle maculopathy, correlating with visual field defects detected on automated perimetry in the asymptomatic eyes.

CONCLUSION

Although symptomatic postoperative vision loss is a rare complication of cardiac surgery, intraoperative retinal microvascular nonperfusion as a consequence of extracorporeal circulation of blood may be a more common and under-recognized occurrence.

Acute ischemic optic nerve disease: Pathophysiology, clinical features and management

Ischemic optic neuropathies are among the leading causes of severe visual acuity loss in people over 50 years of age. They constitute a set of various entities that are clinically, etiologically and therapeutically different. Anatomically, it is necessary to distinguish anterior and posterior forms. From an etiological point of view, the diagnosis of the arteritic form due to giant cell arteritis requires emergent management to prevent blindness and even death in the absence of prompt corticosteroid treatment. When this diagnosis has been ruled out with certainty, non-arteritic ischemic optic neuropathies represent a vast etiological context that in the majority of cases involves a local predisposing factor (small optic nerves, disc drusen) with a precipitating factor (severe hypotension, general anesthesia or dialysis) in a context of vascular disease (sleep apnea syndrome, hypertension, diabetes, etc.). In the absence of specific available treatment, it is the responsibility of the clinician to identify the risk factors involved, in order to reduce the risk of contralateral recurrence that may occur even several years later. Due to their complexity, these pathologies are the subject of debates regarding both the pathophysiological and therapeutic perspectives; this review aims to provide a synthesis of validated knowledge while discussing controversial data.

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

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.

Haemodilution and head-down tilting induce functional injury in the rat optic nerve: A model for peri-operative ischemic optic neuropathy

BACKGROUND

Mechanisms of peri-operative ischaemic optic neuropathy remain poorly understood. Both specific pre-operative and intra-operative factors have been examined by retrospective studies, but no animal model currently exists.

OBJECTIVES

To develop a rodent model of peri-operative ischaemic optic neuropathy. In rats, we performed head-down tilt and/or haemodilution, theorising that the combination damages the optic nerve.

DESIGN

Animal study.

SETTING

Laboratory.

ANIMALS

A total of 36 rats, in four groups, completed the functional examination of retina and optic nerve after the interventions.

INTERVENTIONS

Anaesthetised groups (n>8) were supine (SUP) for 5 h, head-down tilted 70° for 5 h, head-down tilted/haemodiluted for 5 h or SUP/haemodiluted for 5 h. We measured blood pressure, heart rate, intra-ocular pressure and maintained constant temperature.

MAIN OUTCOME MEASUREMENTS

Retinal function (electroretinography), scotopic threshold response (STR) (for retinal ganglion cells) and visual evoked potentials (VEP) (for transmission through the optic nerve). We imaged the optic nerve in vivo and evaluated retinal histology, apoptotic cells and glial activation in the optic nerve. Retinal and optic nerve function were followed to 14 and 28 days after experiments.

RESULTS

At 28 days in head down tilted/haemodiluted rats, negative STR decreased (about 50% amplitude reduction, P = 0.006), VEP wave N2-P3 decreased (70% amplitude reduction, P = 0.01) and P2 latency increased (35%, P = 0.003), optic discs were swollen and glial activation was present in the optic nerve. SUP/haemodiluted rats had decreases in negative STR and increased VEP latency, but no glial activation.

CONCLUSION

An injury partly resembling human ischaemic optic neuropathy can be produced in rats by combining haemodilution and head-down tilt. Significant functional changes were also present with haemodilution alone. Future studies with this partial optic nerve injury may enable understanding of mechanisms of peri-operative ischaemic optic neuropathy and could help discover preventive or treatment strategies.

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.

Trends, Predictors, and Outcomes of Temporary Mechanical Circulatory Support for Postcardiac Surgery Cardiogenic Shock

Postcardiac surgery cardiogenic shock (PCCS) is seen in 2% to 6% of patients who undergo cardiac surgery. There are limited large-scale data on the use of mechanical circulatory support (MCS) in these patients. This study sought to evaluate the in-hospital mortality, trends, and resource utilization for PCCS admissions with and without MCS. A retrospective cohort of PCCS between 2005 and 2014 with and without the use of temporary MCS was identified from the National Inpatient Sample. Admissions for permanent MCS and heart transplant were excluded. Propensity-matching for baseline characteristics was performed. The primary outcome was in-hospital mortality and secondary outcomes included trends in use, hospital costs and lengths of stay. In the period between 2005 and 2014, there were 132,485 admissions with PCCS, with 51.3% requiring MCS. The intra-aortic balloon pump was the predominant device used with a steady increase in other devices. MCS use for more frequent in younger patients, males and those with higher co-morbidity. There was a decrease in MCS use across all demographic categories and hospital characteristics over time. Older age, female sex, previous cardiovascular morbidity and MCS use were independently predictive of higher in-hospital mortality. In 6,830 propensity-matched pairs, PCCS admissions that required MCS use, had higher in-hospital mortality (odds ratio 2.4; p<0.001), higher hospital costs ($98,759 ± 907 vs $81,099 ± 698; p<0.001) but not a longer length of stay compared with those without MCS use. In conclusion, in patients with PCCS, this study noted a steady decrease in MCS use. Use of MCS identified PCCS patients at higher risk for in-hospital mortality and greater resource utilization.

Update on Perioperative Ischemic Optic Neuropathy Associated With Non-ophthalmic Surgery

Perioperative visual loss (POVL) is a rare, serious complication of non-ophthalmic surgeries. Ischemic optic neuropathy (ION), and retinal arterial occlusion (RAO) are the main causes (1, 2). Less frequent are cortical blindness (3), acute glaucoma (4), and choroidal and vitreous hemorrhage (5). ION is the most common cause for which the neurologist or neuro-ophthalmologist is consulted as it is associated either with a normal ophthalmic exam (posterior ION, PION), or less often, with optic nerve (ON) head swelling (anterior ION, AION). The presumed cause is impaired blood supply to the optic nerve (Figure 1). The most common surgical procedures complicated by ION are cardiac surgery and spinal fusion. Retrospective studies, surveys, and case reports are the basis of most knowledge regarding peri-operative ION (poION), with cohort and case-control studies helping to identify candidate risk factors (6, 7). Animal models have provided insight regarding mechanisms (8). This mini-review is an update on the latest advancements regarding poION in non-ophthalmic surgeries in epidemiological, clinical, and animal studies.