Risk of Nonarteritic Anterior Ischemic Optic Neuropathy in Patients Prescribed Semaglutide.

Importance: Anecdotal experience raised the possibility that semaglutide, a glucagon-like peptide 1 receptor agonist (GLP-1 RA) with rapidly increasing use, is associated with nonarteritic anterior ischemic optic neuropathy (NAION). Objective: To investigate whether there is an association between semaglutide and risk of NAION. Design, Setting, and Participants: In a retrospective matched cohort study using data from a centralized data registry of patients evaluated by neuro-ophthalmologists at 1 academic institution from December 1, 2017, through November 30, 2023, a search for International Statistical Classification of Diseases and Related Health Problems, Tenth Revision code H47.01 (ischemic optic neuropathy) and text search yielded 16 827 patients with no history of NAION. Propensity matching was used to assess whether prescribed semaglutide was associated with NAION in patients with type 2 diabetes (T2D) or overweight/obesity, in each case accounting for covarying factors (sex, age, systemic hypertension, T2D, obstructive sleep apnea, obesity, hyperlipidemia, and coronary artery disease) and contraindications for use of semaglutide. The cumulative incidence of NAION was determined with the Kaplan-Meier method and a Cox proportional hazards regression model adjusted for potential confounding comorbidities. Data were analyzed from December 1, 2017, through November 30, 2023. Exposures: Prescriptions for semaglutide vs non-GLP-1 RA medications to manage either T2D or weight. Main Outcomes and Measures: Cumulative incidence and hazard ratio of NAION. Results: Among 16 827 patients, 710 had T2D (194 prescribed semaglutide; 516 prescribed non-GLP-1 RA antidiabetic medications; median [IQR] age, 59 [49-68] years; 369 [52%] female) and 979 were overweight or obese (361 prescribed semaglutide; 618 prescribed non-GLP-1 RA weight-loss medications; median [IQR] age, 47 [32-59] years; 708 [72%] female). In the population with T2D, 17 NAION events occurred in patients prescribed semaglutide vs 6 in the non-GLP-1 RA antidiabetes cohort. The cumulative incidence of NAION for the semaglutide and non-GLP-1 RA cohorts over 36 months was 8.9% (95% CI, 4.5%-13.1%) and 1.8% (95% CI, 0%-3.5%), respectively. A Cox proportional hazards regression model showed higher risk of NAION for patients receiving semaglutide (hazard ratio [HR], 4.28; 95% CI, 1.62-11.29); P < .001). In the population of patients who were overweight or obese, 20 NAION events occurred in the prescribed semaglutide cohort vs 3 in the non-GLP-1 RA cohort. The cumulative incidence of NAION for the semaglutide vs non-GLP-1 RA cohorts over 36 months was 6.7% (95% CI, 3.6%-9.7%) and 0.8% (95% CI, 0%-1.8%), respectively. A Cox proportional hazards regression model showed a higher risk of NAION for patients prescribed semaglutide (HR, 7.64; 95% CI, 2.21-26.36; P < .001). Conclusions and Relevance: This study's findings suggest an association between semaglutide and NAION. As this was an observational study, future study is required to assess causality.

Nonarteritic Anterior Ischemic Optic Neuropathy After Cataract Surgery: A Systematic Review and Meta-Analysis.

BACKGROUND: Nonarteritic anterior ischemic optic neuropathy (NAION) has been reported to occur after cataract surgery. It is not clearly established whether cataract surgery increases the risk of NAION over baseline. EVIDENCE ACQUISITION: Medline, PubMed, Embase, and Cochrane Central registers were systematically searched for eligible studies reporting on postcataract surgery NAION (psNAION) within 1 year. All peer-reviewed publications with events n ≥ 10 were included. Pooled incidence and odds/hazard ratios and 95% confidence intervals (CIs) were extracted and calculated using random effect models for early and delayed psNAION. Time to event data were pooled for temporal analysis of psNAION events within the first year. This systematic review was registered (PROSPERO CRD42021274383). RESULTS: Nine articles met the selection criteria with five studies suitable for meta-analysis. A total of 320 psNAION cases, 1,307 spontaneous NAION (sNAION) cases, 1,587,691 cataract surgeries, and 1,538,897 noncataract surgery controls were included. Pooling of 63,823 cataract surgeries and 161,643 controls showed a hazard ratio of 4.6 (95% CI 2.7-7.8) of psNAION within 1 year of surgery. Pooled unadjusted incidence of psNAION within 2 months was 99.92 (95% CI 38.64-161.19) per 100,000/year, psNAION within 1 year was 32.36 (95% CI 9.38-55.34) per 100,000/year, and sNAION was 8.87 (95% CI 2.12-15.62) per 100,000/year. psNAION cases were older by a mean of 7.6 years; otherwise, pooled odds ratios for baseline risk factors in psNAION vs. sNAION cases were not statistically significant. psNAION within the first year peaked within 72 hrs and at 6 weeks after the surgery with 73% of cases occurring within 6 months. CONCLUSION: The risk of NAION after cataract surgery is four times greater within the first year and usually occurs within 6 months. However, the absolute risk remains low at 1 in 1,000-3,100 surgeries and is unlikely to warrant extra mention for consenting.

Bilateral Simultaneous Nonarteritic Anterior Ischemic Optic Neuropathy: Demographics, Risk Factors, and Visual Outcomes.

BACKGROUND: Although nonarteritic anterior ischemic optic neuropathy is a well-known cause of vision loss, it typically presents unilaterally. Simultaneous, bilateral nonarteritic anterior ischemic optic neuropathy (sNAION) is rare and poorly studied in comparison. This study seeks to characterize the clinical features and risk factors of patients with sNAION compared with unilateral NAION (uNAION). METHODS: In this retrospective case-control study, we reviewed 76 eyes (38 patients) with sNAION and 38 eyes (38 patients) with uNAION (controls) from 4 academic institutions examined between 2009 and 2020. Demographic information, medical history, medication use, symptom course, paraclinical evaluation, and visual outcomes were collected for all patients. RESULTS: No significant differences were observed in demographics, comorbidities and their treatments, and medication usage between sNAION and uNAION patients. sNAION patients were more likely to undergo an investigative work-up with erythrocyte sedimentation rate measurement ( P = 0.0061), temporal artery biopsy ( P = 0.013), lumbar puncture ( P = 0.013), and MRI ( P < 0.0001). There were no significant differences between the 2 groups for visual acuity, mean visual field deviation, peripapillary retinal nerve fiber layer thickness, or ganglion cell-inner plexiform layer thickness at presentation, nor at final visit for those with ≥3 months of follow-up. The sNAION eyes with ≥3 months of follow-up had a smaller cup-to-disc ratio (CDR) at final visit ( P = 0.033). Ten patients presented with incipient NAION, of which 9 suffered vision loss by final visit. CONCLUSION: Aside from CDR differences, the risk factor profile and visual outcomes of sNAION patients seem similar to those of uNAION patients, suggesting similar pathophysiology.

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.

Post-cataract surgery optic neuropathy: a chronological narrative review of the literature and speculation on pathogenesis.

PURPOSE OF REVIEW: To appraise the literature on the incidence of an acute anterior optic neuropathy resembling spontaneous nonarteritic anterior ischemic optic neuropathy (NAION) following uncomplicated cataract surgery and to explore the proposed pathogenesis of both immediate and delayed onset post-cataract surgery optic neuropathy (PCSON). RECENT FINDINGS: A number of case reports, case series, and retrospective case-controlled, big data, and population-based studies have identified an apparent association between cataract surgery and the occurrence of an acute anterior optic neuropathy that can either be immediate or delayed in onset. However, a recent study found no link between modern day cataract surgery and an increased risk of an acute anterior optic neuropathy. SUMMARY: Immediate PCSON appears to be related to negative perfusion pressure at the level of the optic disc due to increased intraocular pressure. The pathogenesis of delayed PCSON is unknown but probably multifactorial. Patients who have experienced spontaneous NAION or PCSON in one eye may be at risk of PCSON in the fellow eye.

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.

A Population-Based Study of Anterior Ischemic Optic Neuropathy Following Cataract Surgery.

PURPOSE: To determine if there is an increased incidence rate of post-cataract surgery (pcs) anterior ischemic optic neuropathy (AION) compared to spontaneous AION (sAION). DESIGN: Retrospective, population-based cohort. METHODS: Patients diagnosed with AION from January 1, 1990, through December 31, 2016, while residing in Olmsted County, Minnesota. Patients with cataract surgery preceding AION were included in the pcsAION cohort defined in 2 ways: AION within 2 months and AION within 1 year of cataract surgery. The incidence rates of pcsAION and sAION were compared using Poisson regression models. RESULTS: During the study period, 102 residents developed AION. The median age was 65 years (range, 40-90 years), 44 (43.1%) were female. Twenty of 102 (19.6%) patients had previous cataract surgery, of which 2 and 9 developed AION within 2 months and 1 year of surgery, respectively. The annual incidence rate of pcsAION within 2 months of surgery (8.6 per 100,000) was not significantly greater than the annual incidence rate of sAION (6.9 per 100,000; P = .78). However, the annual incidence rate of pcsAION within 1 year of surgery (38.9 per 100,000) was significantly higher than the incidence rate of sAION (6.5 per 100,000; P < .001). CONCLUSION: The incidence of AION is increased in the first year after cataract surgery, but not in the early (i.e., 2 months) postoperative period.

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.

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.

Incidence of nonarteritic ischemic optic neuropathy following topical clear corneal cataract surgery: survey and meta-analysis.

OBJECTIVE: We estimate the incidence and characteristics of post-cataract-surgery nonarteritic ischemic optic neuropathy (PCNAION) after topical clear corneal cataract extraction (CCCE) in Canada. DESIGN: Canada-wide internet survey and meta-analysis PARTICIPANTS: All certified Canadian ophthalmologists in the Canadian Ophthalmological Society directory, or belonging to a provincial ophthalmology internet group. METHODS: Identical surveys were distributed to 5 regions in Canada. CCCE surgeons were asked to estimate the number of CCCE they had performed in their career, and the number of PCNAION events that occurred within 1 year after CCCE. The results were analyzed using a random effects meta-analysis of proportions for rare events. RESULTS: The estimated survey response rate was 18%-32%. The 182 survey respondents performed a total of 1 499 694 CCCE with 107 events of PCNAION. Twenty-six percent of surgeons had at least one patient with PCNAION. Meta-analysis revealed a pooled estimate incidence of 2.8 PCNAION events (95% confidence interval 1.6-4.7) per 100 000 cataract procedures during the year after cataract surgery. Seventy-seven percent (82/107) of the PCNAION cases occurred within 3 weeks of surgery, and 7 patients had bilateral PCNAION. CONCLUSIONS: PCNAION is a rare complication after topical CCCE. Its incidence is important to estimate for patient care and epidemiologic reasons.

Risk of Nonarteritic Anterior Ischemic Optic Neuropathy After Cataract Surgery.

PURPOSE: To determine whether the development of nonarteritic anterior ischemic optic neuropathy (NAION) is increased after receiving cataract surgery in a large general population. DESIGN: Nationwide, population-based, retrospective cohort study. METHODS: Setting: A 12-year nationwide, population-based, retrospective cohort study including 1,025,340 beneficiaries in the 2002-2013 Korean National Health Insurance Service database. PATIENTS: We identified 40,356 patients who had undergone cataract surgery and matched non-cataract surgery controls (1:2) using estimated propensity scores in reference to age, sex, demographics, comorbidities, and co-medications. OBSERVATIONS: Kaplan-Meier curves and Cox proportional hazard models were generated to determine the risk of developing NAION in the cataract surgery group compared to the non-cataract surgery group. MAIN OUTCOME MEASURES: Effect (hazard ratio [HR]) of cataract surgery on NAION development. RESULTS: The 10-year incidence probability of NAION was 0.70% (95% confidence interval [CI], 0.55%-0.86%) in the cataract surgery group and 0.27% (95% CI, 0.25%-0.29%) in the non-cataract surgery group (P < .0001, log-rank test). The cataract surgery group had an increased risk of developing NAION compared to the non-cataract surgery group (HR = 1.80; 95% CIs, 1.46-2.21) even after adjusting for demographics, comorbidities, Charlson comorbidity index, and co-medications. CONCLUSION: Our results suggest that patients undergoing cataract surgery have an increased risk of NAION.

Prevalence and incidence of non-arteritic anterior ischaemic optic neuropathy in South Korea: a nationwide population-based study.

AIMS: To determine the age and sex-specific prevalence and incidence of non-arteritic anterior ischaemic optic neuropathy (NAION) in South Korea. METHODS: This is a nationwide population-based study using data from the Korean national health claims database to identify patients with NAION using the registration programme database, which comprises ophthalmologist-confirmed NAION from 2011 through 2015. We evaluated prevalence and incidence rates using these data. RESULTS: Among 25 816 797 of entire population 40 years of age or older, 26 167 patients had NAION (47.8% men) during the 5-year study period. The prevalence in the general population 40 years of age or older was 102.87 (95% CI 95.22 to 110.53) per 100 000 people. In men, it was 111.10 (95% CI 101.19 to 121.02), and in women, it was 94.64 (95% CI 89.25 to 100.03) per 100 000 people. The prevalence increased with advancing age and peaked at 70-74 years in men and 65-69 years in women. The incidence in the general population 40 years of age or older was 11.35 (95% CI 10.37 to 12.33) per 100 000 person-years. In men, it was 14.89 (95% CI 12.26 to 16.91), and in women, it was 9.92 (95% CI 8.85 to 10.99) per 100 000 person-years. The incidence increased with advancing age and peaked at 80-84 years in men and 70-74 years in women. CONCLUSIONS: The prevalence and incidence estimates of NAION are comparable with those of Caucasians. These detailed estimates could promote understanding of the disease's pathophysiology and allow for appropriate planning within the healthcare system.

The risk of ischemic optic neuropathy post phacoemulsification cataract surgery.

INTRODUCTION: The aim was to study the risk of non arteritic ischemic optic neuropathy after phacoemulsification cataract surgery. METHODS: This study was conducted at King Hussein Medical Center during the period between January 2015 and July 2016. Patients attending ophthalmology clinic complaining of decreased vision due to lens opacity were evaluated. Patients were divided into two groups. First group included patients with no medical illness and second group included patients with diabetes mellitus, hypertension or hyperlipidemia. The two groups were further divided into two subgroups. First subgroup included patients who had phacoemulsification surgery and second subgroup did not have surgery. All patients were followed up for 6 months. They were assessed by neuro-ophthalmologist looking for ischemic optic neuropathy. RESULTS: A total number of 568 patients were enrolled. Group 1A included patients with no medical illness who underwent surgery and group 1B did not undergo surgery. The number of patients in these two subgroups was 119 and 103 respectively. Number of patients in group 2A (medical illness and surgery) was 188 and number of patients in group 2B (medical illness and no surgery) was 130. The incidence of ischemic optic neuropathy was 4.3 % in group 2A, 4.2 % in group 1A, 0.8% in group 2B, and 0% in group 1B. CONCLUSION: Phacoemulsification is a risk factor for non arteritic ischemic optic neuropathy independent of the presence of medical risk factors. Suggested mechanisms would be local anaesthesia, intraocular pressure fluctuation and local intraocular inflammation.

Strategies to prevent ischemic optic neuropathy following major spine surgery: A narrative review.

Postoperative vision loss following a major spine operation is a rare but life-changing event. Most of reports have been linked to ischemic optic neuropathy, and patients undergoing surgery for scoliosis correction or posterior lumbar fusion seem to be at the highest risk. Despite that some key risk factors have been identified, much of the pathophysiology still remain unknown. In fact, whereas only a minority of patients at high risk will present this complication, others with similar risk factors undergoing different procedures may not develop it at all. On the other hand, even when all preventive measures have been taken, ischemic optic neuropathy may still occur. Therefore, it is appropriate for clinicians involved in these cases to inform their patients about the existence of a small but unpredictable risk of vision loss. Since ischemic optic neuropathy is deemed to be the leading cause of vision loss in the context of major spine surgery in prone position, this review will be focused on its main aspects related to the frequency, diagnosis, predisposing factors, and prevention. Regrettably, no treatment has been proved to be effective for this condition.

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

BACKGROUND: Ischemic optic neuropathy is the most common form of perioperative visual loss, with highest incidence in cardiac and spinal fusion surgery. To date, potential risk factors have been identified in cardiac surgery by only small, single-institution studies. To determine the preoperative risk factors for ischemic optic neuropathy, the authors used the National Inpatient Sample, a database of inpatient discharges for nonfederal hospitals in the United States. METHODS: Adults aged 18 yr or older admitted for coronary artery bypass grafting, heart valve repair or replacement surgery, or left ventricular assist device insertion in National Inpatient Sample from 1998 to 2013 were included. Risk of ischemic optic neuropathy was evaluated by multivariable logistic regression. RESULTS: A total of 5,559,395 discharges met inclusion criteria with 794 (0.014%) cases of ischemic optic neuropathy. The average yearly incidence was 1.43 of 10,000 cardiac procedures, with no change during the study period (P = 0.57). Conditions increasing risk were carotid artery stenosis (odds ratio, 2.70), stroke (odds ratio, 3.43), diabetic retinopathy (odds ratio, 3.83), hypertensive retinopathy (odds ratio, 30.09), macular degeneration (odds ratio, 4.50), glaucoma (odds ratio, 2.68), and cataract (odds ratio, 5.62). Female sex (odds ratio, 0.59) and uncomplicated diabetes mellitus type 2 (odds ratio, 0.51) decreased risk. CONCLUSIONS: The incidence of ischemic optic neuropathy in cardiac surgery did not change during the study period. Development of ischemic optic neuropathy after cardiac surgery is associated with carotid artery stenosis, stroke, and degenerative eye conditions.

Relative Frequencies of Arteritic and Nonarteritic Anterior Ischemic Optic Neuropathy in an Arab Population.

BACKGROUND: To evaluate the relative frequencies of arteritic and nonarteritic anterior ischemic optic neuropathy (AION) in an Arab population and to compare and contrast these findings with known epidemiological data from Caucasian populations. METHODS: A retrospective review of the medical records of all patients diagnosed with AION at the King Khaled Eye Specialist Hospital (KKESH) in Riyadh, Saudi Arabia, between 1997 and 2012. RESULTS: Of 171 patients with AION, 4 had biopsy-proven giant-cell arteritis (GCA). The relative frequencies of arteritic anterior ischemic optic neuropathy (AAION) and nonarteritic anterior ischemic optic neuropathy (NAION) in this Arab cohort were 2.3% and 97.7%, respectively. CONCLUSIONS: The relative frequencies of arteritic anterior ischemic optic neuropathy and nonarteritic anterior ischemic optic neuropathy differ between Arab and North American clinic-based populations, with giant-cell arteritis-related ischemia being much less frequent in Saudi Arabia.

Post-Cataract Surgery Optic Neuropathy: Prevalence, Incidence, Temporal Relationship, and Fellow Eye Involvement.

PURPOSE: To reassess the prevalence and incidence of post-cataract surgery optic neuropathy (PCSON) in the modern era. DESIGN: Retrospective cohort study. METHODS: Setting: Single-center tertiary care practice. STUDY POPULATION: All patients with a diagnosis of nonarteritic anterior ischemic optic neuropathy (NAION) seen in the Wilmer Eye Network system between January 1, 2010 and December 31, 2014 were included. Inclusion was based on the following: (1) a history of an acute unilateral decrease in vision, (2) a visual field defect consistent with NAION, (3) a relative afferent pupillary defect, (4) observed optic disc swelling, and (5) no other etiology being found. MAIN OUTCOME MEASURES: The prevalence and incidence of PCSON and the temporal association between surgery and onset of PCSON. The secondary outcome was the risk of PCSON in the fellow eye of patients with prior unilateral spontaneous NAION. RESULTS: One hundred eighty-eight patients had developed NAION during the study period. Of these, 18 (9.6%) had undergone cataract surgery (CS) during the year prior to developing NAION. There was no significant temporal pattern associated with the distribution of NAION cases (P = .28). The incidence of PCSON in patients who had noncomplex CS was 10.9 cases per 100 000 (95% CI, 1.3, 39.4). CONCLUSIONS: Our data indicate that both the prevalence and incidence of NAION after modern CS are comparable to those of the general population and that there is no significant temporal relationship between modern CS and the subsequent development of NAION in the operated eye. Thus, although this study has inherent biases owing to its retrospective nature, concern regarding an increased risk of PCSON in the fellow eye in patients who have experienced it or spontaneous NAION in 1 eye may be unwarranted.

Perioperative Visual Loss in Spine Fusion Surgery: Ischemic Optic Neuropathy in the United States from 1998 to 2012 in the Nationwide Inpatient Sample.

BACKGROUND: Perioperative ischemic optic neuropathy (ION) causes visual loss in spinal fusion. Previous case-control studies are limited by study size and lack of a random sample. The purpose of this study was to study trends in ION incidence in spinal fusion and risk factors in a large nationwide administrative hospital database. METHODS: In the Nationwide Inpatient Sample for 1998 to 2012, procedure codes for posterior thoracic, lumbar, or sacral spine fusion and diagnostic codes for ION were identified. ION was studied over five 3-yr periods (1998 to 2000, 2001 to 2003, 2004 to 2006, 2007 to 2009, and 2010 to 2012). National estimates were obtained using trend weights in a statistical survey procedure. Univariate and Poisson logistic regression assessed trends and risk factors. RESULTS: The nationally estimated volume of thoracic, lumbar, and sacral spinal fusion from 1998 to 2012 was 2,511,073. ION was estimated to develop in 257 patients (1.02/10,000). The incidence rate ratio (IRR) for ION significantly decreased between 1998 and 2012 (IRR, 0.72 per 3 yr; 95% CI, 0.58 to 0.88; P = 0.002). There was no significant change in the incidence of retinal artery occlusion. Factors significantly associated with ION were age (IRR, 1.24 per 10 yr of age; 95% CI, 1.05 to 1.45; P = 0.009), transfusion (IRR, 2.72; 95% CI, 1.38 to 5.37; P = 0.004), and obesity (IRR, 2.49; 95% CI, 1.09 to 5.66; P = 0.030). Female sex was protective (IRR, 0.30; 95% CI, 0.16 to 0.56; P = 0.0002). CONCLUSIONS: Perioperative ION in spinal fusion significantly decreased from 1998 to 2012 by about 2.7-fold. Aging, male sex, transfusion, and obesity significantly increased the risk.