Reexamining the Incidence of Nonarteritic Anterior Ischemic Optic Neuropathy: A Rochester Epidemiology Project Study.

BACKGROUND: This study aims to determine the population-based incidence and characterize the features of nonarteritic anterior ischemic optic neuropathy (NAION) using the Rochester Epidemiology Project (REP). METHODS: All patients diagnosed with an optic neuropathy from January 1, 1990, to December 31, 2016, were retrospectively reviewed to identify incident cases of NAION using the REP database, which is a record-linkage system of medical records for all patient-physician encounters among Olmsted County, Minnesota residents. The overall incidence of NAION was estimated using the age-specific and sex-specific population figures for Olmsted County census data for 1990 through 2016. Visual outcomes and risk factors were evaluated. The systemic risk factors were compared with age-matched controls. RESULTS: One hundred four patients were diagnosed with NAION during the 26-year study period. The overall age and sex adjusted incidence was 3.89 per 100,000 individuals (95% confidence interval [CI]: 3.14-4.65). The incidence was 7.73 (CI: 6.24-9.22) in patients aged 40 years or older and 10.19 (CI: 8.15-12.23) in patients aged 50 years or older. Median age at diagnosis was 65 years (range, 40-90 years), and 59 (56.7%) were male. The median logMAR visual acuity at presentation was 0.35 (Snellen equivalent of 20/40) with 14 patients (13.5%) having vision of counting fingers or worse. Among the 91 patients with final visual acuity outcome data available, the median visual acuity was 0.40 (Snellen equivalent of 20/50) with 12 patients (13.2%) having vision of counting fingers or worse. Twenty-four patients (26.4%) were noted to have final acuity at least 3 Snellen lines worse than at presentation, whereas 17 patients (18.7%) were noted to improve by at least 3 lines. The median mean deviation on automated visual field testing was -10.2 dB at presentation and -11.1 dB at follow-up. Twenty-two patients (21.2%) suffered NAION in the fellow eye; the median interval between involvement of the first and second eyes was 1.39 years. Systemic diseases present in the NAION cohort included hypertension (79.8%), diabetes mellitus (39.4%), obstructive sleep apnea (23.1%), and hyperlipidemia (74.0%), which were all statistically higher than age-matched controls. CONCLUSIONS: NAION is a relatively common optic neuropathy in elderly patients with vascular risk factors. Our data indicate that the incidence of NAION has remained relatively stable in the population of Olmsted County over the past 4 decades.

KR20 and KR21 for Some Nondichotomous Data (It's Not Just Cronbach's Alpha).

This article presents some equivalent forms of the common Kuder-Richardson Formula 21 and 20 estimators for nondichotomous data belonging to certain other exponential families, such as Poisson count data, exponential data, or geometric counts of trials until failure. Using the generalized framework of Foster (2020), an equation for the reliability for a subset of the natural exponential family have quadratic variance function is derived for known population parameters, and both formulas are shown to be different plug-in estimators of this quantity. The equivalent Kuder-Richardson Formulas 20 and 21 are given for six different natural exponential families, and these match earlier derivations in the case of binomial and Poisson data. Simulations show performance exceeding that of Cronbach's alpha in terms of root mean square error when the formula matching the correct exponential family is used, and a discussion of Jensen's inequality suggests explanations for peculiarities of the bias and standard error of the simulations across the different exponential families.

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.

Population-Based Incidence of Optic Neuritis in the Era of Aquaporin-4 and Myelin Oligodendrocyte Glycoprotein Antibodies.

PURPOSE: To re-evaluate the population-based incidence of optic neuritis in the era of aquaporin-4-immunoglobulin G (AQP4-IgG) and myelin oligodendrocyte glycoprotein (MOG)-IgG, which are biomarkers of optic neuritis that is distinct from multiple sclerosis (MS). Over the past 15 years, 2 new biomarkers have been discovered that allow for further characterization of the cause of atypical optic neuritis: AQP4-IgG and MOG-IgG. DESIGN: Retrospective, population-based cohort. SETTING: population-based. PARTICIPANTS: all residents of Olmsted County, Minnesota, with optic neuritis diagnosed between January 1, 2000, and December 31, 2018. METHODS: The Rochester Epidemiology Project database was used to identify patients. Sera were tested for AQP4-IgG and MOG-IgG by using a live-cell-based flow cytometry assay. Main outcome measurements were the incidence and cause of optic neuritis. RESULTS: Optic neuritis was diagnosed in 110 patients, providing an annual incidence of 3.9 per 100,000. The final diagnosis was MS in 57%, idiopathic in 29%, MOG-IgG-associated disorder in 5%, AQP4-IgG-seropositive neuromyelitis optic spectrum disorder (NMOSD) in 3%, infectious type in 2%, sarcoidosis in 2%, seronegative NMOSD in 1%, and medication-related in 1%. All 3 patients positive for AQP4-IgG had more than 1 optic neuritis attack, 2 with residual no light perception vision in at least 1 eye. Among MOG-IgG-positive patients, 4 of 6 patients had recurrent optic neuritis, and all 6 had a final visual acuity of 20/30 or better. CONCLUSIONS: At a population level, AQP4-IgG and MOG-IgG account for 9% of optic neuritis and are associated with recurrent attacks, but MOG-IgG optic neuritis has a better visual outcome than AQP4-IgG optic neuritis.

Stroke Rate, Subtype, and Cardiovascular Risk Factors in Nonarteritic Anterior Ischemic Optic Neuropathy: A Population-Based Study.

BACKGROUND: Nonarteritic anterior ischemic optic neuropathy (NAION) is a common cause of acute optic neuropathy in adults and is associated with vascular risk factors. Owing to the overlapping risk factor profiles between NAION and cerebral stroke, previous studies have produced conflicting results with regard to NAION as an independent risk factor for stroke. METHODS: A retrospective chart review was conducted using the Rochester Epidemiology Project database to identify all cases of NAION occurring among Olmsted County, Minnesota residents from January 1, 1990, through December 31, 2016. Stroke events were characterized using clinical and radiologic data. Comparison was made to an age- and sex-matched control group with similar vascular risk factors. RESULTS: One-hundred four patients with NAION and 104 control subjects were analyzed. Median age at diagnosis was 65 years (range, 40-90 years). Thirteen patients (13%) with NAION and 10 controls (10%) had symptomatic strokes after the age of 40 years. Among patients with NAION, 6 (46%) suffered a stroke before the diagnosis of NAION, 5 (39%) at least 5 months after the NAION diagnosis, and 2 patients (15%) suffered strokes both before and after the NAION. The cumulative probability of symptomatic strokes for patients with NAION was not significantly different than for controls (hazard ratio = 1.50, 95% confidence interval: 0.66-3.42; P = 0.34). There were no cardioembolic strokes within 1 month of the NAION diagnosis. The mechanism of symptomatic strokes did not differ between the 2 groups. CONCLUSIONS: NAION does not confer an increased risk of symptomatic stroke beyond the risk posed by age and existing vascular risk factors.