Cerebroventricular deformation and vector mapping, a topographic visualizer for surgical interventions in pediatric hydrocephalus.

OBJECTIVE: Hydrocephalus is a challenging neurosurgical condition due to nonspecific symptoms and complex brain-fluid pressure dynamics. Typically, the assessment of hydrocephalus in children requires radiographic or invasive pressure monitoring. There is usually a qualitative focus on the ventricular spaces even though stress and shear forces extend across the brain. Here, the authors present an MRI-based vector approach for voxelwise brain and ventricular deformation visualization and analysis. METHODS: Twenty pediatric patients (mean age 7.7 years, range 6 months-18 years; 14 males) with acute, newly diagnosed hydrocephalus requiring surgical intervention for symptomatic relief were randomly identified after retrospective chart review. Selection criteria included acquisition of both pre- and posttherapy paired 3D T1-weighted volumetric MRI (3D T1-MRI) performed on 3T MRI systems. Both pre- and posttherapy 3D T1-MRI pairs were aligned using image registration, and subsequently, voxelwise nonlinear transformations were performed to derive two exemplary visualizations of compliance: 1) a whole-brain vector map projecting the resulting deformation field on baseline axial imaging; and 2) a 3D heat map projecting the volumetric changes along ventricular boundaries and the brain periphery. RESULTS: The patients underwent the following interventions for treatment of hydrocephalus: endoscopic third ventriculostomy (n = 6); external ventricular drain placement and/or tumor resection (n = 10); or ventriculoperitoneal shunt placement (n = 4). The mean time between pre- and postoperative imaging was 36.5 days. Following intervention, the ventricular volumes decreased significantly (mean pre- and posttherapy volumes of 151.9 cm3 and 82.0 cm3, respectively; p < 0.001, paired t-test). The largest degree of deformation vector changes occurred along the lateral ventricular spaces, relative to the genu and splenium. There was a significant correlation between change in deformation vector magnitudes within the cortical layer and age (p = 0.011, Pearson), as well as between the ventricle size and age (p = 0.014, Pearson), suggesting higher compliance among infants and younger children. CONCLUSIONS: This study highlights an approach for deformation analysis and vector mapping that may serve as a topographic visualizer for therapeutic interventions in patients with hydrocephalus. A future study that correlates the degree of cerebroventricular deformation or compliance with intracranial pressures could clarify the potential role of this technique in noninvasive pressure monitoring or in cases of noncompliant ventricles.

Application of novel non-invasive ophthalmic imaging to visualize peripapillary wrinkles, retinal folds and peripapillary hyperreflective ovoid mass-like structures associated with elevated intracranial pressure.

Background: Elevated intracranial pressure (ICP) is a serious and potentially life-threatening condition, for which clinically useful non-invasive measures have been elusive, in some cases due to their inadequate sensitivity and specificity. Our aim was to evaluate novel non-invasive ophthalmic imaging of selected pathological features seen in elevated ICP, namely peripapillary hyperreflective ovoid mass-like structures (PHOMS), peripapillary wrinkles (PPW) and retinal folds (RF) as potential biomarkers of elevated ICP. Methods: This single-center pilot study included subjects with untreated or incompletely treated high ICP. The retinas of these subjects were evaluated with averaged en-face optical coherence tomography (OCT), OCT retinal cross-sections (OCT B-scans), adaptive optics scanning light ophthalmoscopy (AOSLO), and fundus photos. Results: Seven subjects were included in the study. 6 subjects with high ICP (5 idiopathic intracranial hypertension, 1 medication induced, 30.8 ± 8.6 years, 75% female, 5 with papilledema) and 1 control (20-25 years) were included. PHOMS, PPW and RF were present in all subjects with papilledema, but neither in the high ICP subject without papilledema nor in the control subject. Averaged en-face OCT scans and AOSLO were more sensitive for PPW and RF than OCT B-scans and commercial fundus photos. Conclusion: PPW, RF and PHOMS volume have potential as non-invasive biomarkers of ICP. Novel imaging modalities may improve sensitivity. However, lack of automated image acquisition and processing limits current widespread adoption in clinical settings. Further research is needed to validate these structures as biomarkers for elevated ICP and improve clinical utility.

Review of evidence for treatments of acute non arteritic anterior ischemic optic neuropathy.

OBJECTIVE: To review treatment modalities that have been studied in acute non arteritic anterior ischemic optic neuropathy (NAION). METHODS: We performed a comprehensive literature search of English language publications in the last 5 years, with human species and NAION. Articles were reviewed to identify those that described original research on treatment of acute NAION. Study type, setting, duration, interventions, and results were extracted and articles were reviewed for biases and limitations. RESULTS: We identified 22 kinds of treatment varying by compound and modality. These include topical, intravitreal, and systemic drugs as well as surgical approaches. Evidence for efficacy ranges from expert opinion to randomized control trials. CONCLUSIONS: Although several treatments are utilized in practice, none of these have high quality evidence of efficacy to improve visual outcomes.  Continued collaborative research is necessary to complete high quality studies in order identify effective therapies for this rare and blinding disease.

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.

A Comparative Study of Large Language Models, Human Experts, and Expert-Edited Large Language Models to Neuro-Ophthalmology Questions.

BACKGROUND: While large language models (LLMs) are increasingly used in medicine, their effectiveness compared with human experts remains unclear. This study evaluates the quality and empathy of Expert + AI, human experts, and LLM responses in neuro-ophthalmology. METHODS: This randomized, masked, multicenter cross-sectional study was conducted from June to July 2023. We randomly assigned 21 neuro-ophthalmology questions to 13 experts. Each expert provided an answer and then edited a ChatGPT-4-generated response, timing both tasks. In addition, 5 LLMs (ChatGPT-3.5, ChatGPT-4, Claude 2, Bing, Bard) generated responses. Anonymized and randomized responses from Expert + AI, human experts, and LLMs were evaluated by the remaining 12 experts. The main outcome was the mean score for quality and empathy, rated on a 1-5 scale. RESULTS: Significant differences existed between response types for both quality and empathy (P < 0.0001, P < 0.0001). For quality, Expert + AI (4.16 ± 0.81) performed the best, followed by GPT-4 (4.04 ± 0.92), GPT-3.5 (3.99 ± 0.87), Claude (3.6 ± 1.09), Expert (3.56 ± 1.01), Bard (3.5 ± 1.15), and Bing (3.04 ± 1.12). For empathy, Expert + AI (3.63 ± 0.87) had the highest score, followed by GPT-4 (3.6 ± 0.88), Bard (3.54 ± 0.89), GPT-3.5 (3.5 ± 0.83), Bing (3.27 ± 1.03), Expert (3.26 ± 1.08), and Claude (3.11 ± 0.78). For quality (P < 0.0001) and empathy (P = 0.002), Expert + AI performed better than Expert. Time taken for expert-created and expert-edited LLM responses was similar (P = 0.75). CONCLUSIONS: Expert-edited LLM responses had the highest expert-determined ratings of quality and empathy warranting further exploration of their potential benefits in clinical settings.

Acute Optic Neuropathy in Older Adults: Differentiating Between MOGAD Optic Neuritis and Nonarteritic Anterior Ischemic Optic Neuropathy.

BACKGROUND AND OBJECTIVES: Myelin oligodendrocyte glycoprotein antibody-associated disease optic neuritis (MOGAD-ON) and nonarteritic anterior ischemic optic neuropathy (NAION) can cause acute optic neuropathy in older adults but have different managements. We aimed to determine differentiating factors between MOGAD-ON and NAION and the frequency of serum MOG-IgG false positivity among patients with NAION. METHODS: In this international, multicenter, case-control study at tertiary neuro-ophthalmology centers, patients with MOGAD presenting with unilateral optic neuritis as their first attack at age 45 years or older and age-matched and sex-matched patients with NAION were included. Comorbidities, clinical presentations, acute optic disc findings, optical coherence tomography (OCT) findings, and outcomes were compared between MOGAD-ON and NAION. Multivariate analysis was performed to find statistically significant predictors of MOGAD-ON. A separate review of consecutive NAION patients seen at Mayo Clinic, Rochester, from 2018 to 2022, was conducted to estimate the frequency of false-positive MOG-IgG in this population. RESULTS: Sixty-four patients with unilateral MOGAD-ON were compared with 64 patients with NAION. Among patients with MOGAD-ON, the median age at onset was 56 (interquartile range [IQR] 50-61) years, 70% were female, and 78% were White. Multivariate analysis showed that eye pain was strongly associated with MOGAD-ON (OR 32.905; 95% CI 2.299-473.181), while crowded optic disc (OR 0.033; 95% CI 0.002-0.492) and altitudinal visual field defect (OR 0.028; 95% CI 0.002-0.521) were strongly associated with NAION. On OCT, peripapillary retinal nerve fiber layer (pRNFL) thickness in unilateral MOGAD-ON was lower than in NAION (median 114 vs 201 µm, p < 0.001; median pRNFL thickening 25 vs 102 µm, p < 0.001). MOGAD-ON had more severe vision loss at nadir (median logMAR 1.0 vs 0.3, p < 0.001), but better recovery (median logMAR 0.1 vs 0.3, p = 0.002). In the cohort of consecutive NAION patients, 66/212 (31%) patients with NAION were tested for MOG-IgG and 8% (95% CI 1%-14%) of those had false-positive serum MOG-IgG at low titers. DISCUSSION: Acute unilateral optic neuropathy with optic disc edema in older adults can be caused by either MOGAD-ON or NAION. Detailed history, the degree of pRNFL swelling on OCT, and visual outcomes can help differentiate the entities and prevent indiscriminate serum MOG-IgG testing in all patients with acute optic neuropathy.

Multi-registry analysis of patients with multiple sclerosis and neuromyelitis optica to improve capture of demographic data and compare visual outcomes.

IMPORTANCE: The American Academy of Neurology Axon Registry® provides real-world data for patients with multiple sclerosis and neuro-myelitis optica. However, some data are incomplete (e.g. demographics) and some relevant outcomes are not systematically captured in neurology documentation (e.g. visual acuity). The American Academy of Ophthalmology IRIS® Registry (Intelligent Research in Sight) contains demographic and visual function data that may complement Axon Registry-derived data to enhance understanding of real-world visual outcomes in neurological disease. OBJECTIVE: To combine Axon Registry and IRIS Registry data to reduce missingness of demographic information and characterize visual outcomes in patients with multiple sclerosis and neuro-myelitis optica. DESIGN: Cross-sectional study. SETTING: Outpatient neurology and ophthalmology clinical practices. PARTICIPANTS: Patients participating in both registries between January 1, 2014 through December 10, 2021 were included if they had repeat ICD-9/10 codes for with multiple sclerosis or neuro-myelitis optica in the Axon registry. EXPOSURE: Diagnosis (multiple sclerosis or neuro-myelitis optica). MAIN OUTCOME AND MEASURE: Age, sex, race and ethnicity were assessed in the individual registries and classified as conflicting, missing, or not missing in the combined data set. The IRIS Registry contributed visual acuity data. RESULTS: Among 60,316 patients with multiple sclerosis and 1,068 patients with neuro-myelitis optica in the Axon Registry, 14,085 and 252 had temporal overlap in the IRIS Registry. Combining data reduced missing or conflicting data for race and ethnicity by 15-19 % (absolute reduction, all p ≤ 0.0005), but not age (p = 1.0) or gender (p = 0.08). 10,907 patients with MS and 142 with NMO had visual acuity data in the IRIS Registry. Visual acuity averaged between eyes was worse in patients with NMO after adjusting for age and gender (0.17 logMAR, 95 %CI 0.12,0.21, p < 0.0005). CONCLUSION AND RELEVANCE: Using data from two registries reduced missing data for race and ethnicity and enabled examination of outcomes captured in the IRIS Registry for conditions that are diagnosed more frequently in the Axon Registry, demonstrating the utility of a multi-registry analysis.

Which OCT Measure of the Optic Nerve Head Improves Fastest? Towards Optimizing Early Detection of Resolving Papilledema in Children.

Purpose: Optical coherence tomography (OCT) has been used to monitor papilledema. This study aims to determine which OCT-derived measures of the optic nerve head (ONH) detect resolving papilledema in children faster than standard OCT measures. Methods: Children (≤18 years of age) with papilledema who completed optic nerve SD-OCT pretreatment and had evidence of treatment response on one or more follow-up OCTs within 4 months were included. Standard (mean circumpapillary retinal nerve fiber layer [cpRNFL] thickness), device-derived (per-quadrant cpRNFL) and custom (ONH height, maximum Bruch's membrane displacement [BMD], ONH volume [ONHV], and BMD volume) OCT measures were calculated. Per-eye generalized estimating equations (GEEs) modelled changes in device-derived and custom measures as a function of mean cpRNFL to identify those measures that resolved faster during early (0-2 months) follow-up. Mean cpRNFL coefficients of greater than 1 indicated faster resolving papilledema. Results: We included 52 eyes of 29 children (mean age, 12.8 years; 72.4% female). In analysis of early follow-up visits (38 eyes from 22 children), nasal cpRNFL and maximum BMD in each quadrant resolved faster than mean cpRNFL (GEE coefficients range, 1.14-3.37). Inferior cpRNFL, superior, nasal, and inferior ONH heights and ONHV resolved slower than mean cpRNFL (GEE coefficients range, 0.67-0.87). Conclusions: Nasal cpRNFL is a promising device-derived OCT measure for the early detection of resolving papilledema in children compared with mean cpRNFL. Maximum BMD, a custom measure, also shows promise, but its calculation has not yet been incorporated into commercial OCT devices. Translational Relevance: This study guides the optimal use of OCT in capturing resolving papilledema in children.

Evolution of Disparities in Outpatient Ophthalmic Care at a Tertiary Care Center in California at the Beginning of and One Year into the COVID-19 Public Health Emergency.

PURPOSE: To compare disparities in outpatient ophthalmic care during early and later periods of the COVID-19 public health emergency. METHODS: This cross-sectional study compared non-peri-operative outpatient ophthalmology visits by unique patients at an adult ophthalmology practice affiliated with a tertiary-care academic medical center in the Western US during three time periods: pre-COVID (3/15/19-4/15/19), early-COVID (3/15/20-4/15/20), and late-COVID (3/15/21-4/15/21). Differences in participant demographics, barriers to care, visit modality (telehealth, in person), and subspeciality of care were studied using unadjusted and adjusted models. RESULTS: There were 3095, 1172 and 3338 unique patient-visits during pre-COVID, early-COVID and late-COVID (overall age 59.5 ± 20.5 years, 57% female, 41.8% White, 25.9% Asian, 16.1% Hispanic). There were disparities in patient age (55.4 ± 21.8 vs. 60.2 ± 19.9 years), race (21.9% vs. 26.9% Asian), ethnicity (18.3% Hispanic vs. 15.2% Hispanic), and insurance (35.9% vs. 45.1% Medicare) as well as changes in modality (14.2% vs. 0% telehealth) and subspecialty (61.6% vs. 70.1% internal exam specialty) in early-COVID vs. pre-COVID (p < .05 for all). In late-COVID, only insurance (42.7% vs. 45.1% Medicare) and modality of care (1.8% vs. 0% telehealth) persisted as differences compared to pre-COVID. CONCLUSIONS: There were disparities in patients receiving outpatient ophthalmology care during early-COVID that returned close to pre-COVID baseline one year later. These results suggest that there has not been a lasting positive or negative disruptive effect of the COVID-19 pandemic on disparities in outpatient ophthalmic care.

Role of Sex in Participation During Virtual Grand Rounds in Ophthalmology.

Importance: Sex disparities exist in academia. Female attendees consistently ask fewer questions in scientific meetings than male attendees, even when they constitute half of the audience. Objective: To assess the role of sex in participation during virtual grand rounds (GR) at a major academic center. Design, Setting, and Participants: In this prospective cohort study, attendees of the Department of Ophthalmology at the University of California, San Francisco, GR from April 2020 to April 2021 were included. All GR were held via a synchronous live video communication platform. During each GR session, a predesignated attendee collected the sex of all attendees, sex of the GR speaker, and sex of each individual who asked a question to the GR speaker in order of inquiry. The GR speakers and audience were unaware of the study. Data were analyzed from June 2021 to April 2023. Main Outcome and Measures: The main analysis assessed the association between being female and asking one of the first 3 questions. Results: A total of 31 virtual ophthalmology GR sessions were observed. The sex of the GR speaker was female in 13 of 31 sessions (42%). The mean (SD) percentage of audience sex at each of the GR sessions was 47% (0.05) female, 45% (0.06) male, and 8% (0.03) unknown. Male attendees were more likely to ask one of the first 3 questions compared with female attendees (prevalence ratio, 3.1; 95% CI, 2.1-4.5; P < .001). Conclusions and Relevance: Male attendees were more likely to ask questions during virtual ophthalmology GR compared with female attendees at an academic medical center. Strategies to encourage equal participation of sex in academic discourse should be encouraged.

Visual Outcomes Following Plasma Exchange for Optic Neuritis: An International Multicenter Retrospective Analysis of 395 Optic Neuritis Attacks.

PURPOSE: To evaluate the effectiveness of plasma exchange (PLEX) for optic neuritis (ON). METHODS: We conducted an international multicenter retrospective study evaluating the outcomes of ON following PLEX. Outcomes were compared to raw data from the Optic Neuritis Treatment Trial (ONTT) using a matched subset. RESULTS: A total of 395 ON attack treated with PLEX from 317 patients were evaluated. The median age was 37 years (range 9-75), and 71% were female. Causes of ON included multiple sclerosis (108), myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD) (92), aquaporin-4-IgG-positive neuromyelitis optica spectrum disorder (AQP4+NMOSD) (75), seronegative-NMOSD (34), idiopathic (83), and other (3). Median time from onset of vision loss to PLEX was 2.6 weeks (interquartile range [IQR], 1.4-4.0). Median visual acuity (VA) at the time of PLEX was count fingers (IQR, 20/200-hand motion), and median final VA was 20/25 (IQR, 20/20-20/60) with no differences among etiologies except MOGAD-ON, which had better outcomes. In 81 (20.5%) ON attacks, the final VA was 20/200 or worse. Patients with poor outcomes were older (P = .002), had worse VA at the time of PLEX (P < .001), and longer delay to PLEX (P < .001). In comparison with the ONTT subset with severe corticosteroid-unresponsive ON, a final VA of worse than 20/40 occurred in 6 of 50 (12%) PLEX-treated ON vs 7 of 19 (37%) from the ONTT treated with intravenous methylprednisolone without PLEX (P = .04). CONCLUSION: Most ON attacks improved with PLEX, and outcomes were better than attacks with similar severity in the ONTT. The presence of severe vision loss at nadir, older age, and longer delay to PLEX predicted a worse outcome whereas MOGAD-ON had a more favorable prognosis. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Accuracy of International Classification of Diseases Codes for Identifying Acute Optic Neuritis.

BACKGROUND: The accuracy of International Classification of Diseases (ICD) codes for identifying cases of acute optic neuritis (aON) is not known. A prior study reported 61% accuracy for ICD code plus MRI consistent with aON within 2 months. This study determined accuracy for ICD code plus MRI within 2 months regardless of results. METHODS: Retrospective chart review was conducted using a medical record research repository of a tertiary care institution from 1998 to 2019. Subjects with ICD-9/10 codes for ON and an MRI brain and/or orbits within 2 months of earliest (initial) ICD code were included. MRI was classified as positive or negative for aON based on report noting gadolinium-contrast enhancement. Clinical diagnosis at the time of initial code was classified as aON, prior ON, considered ON, alternative diagnosis, or unknown based on review of physician authored clinical notes within 7 days of the initial code. Accuracy of ICD code for aON, acute or prior ON, and acute, prior, or considered ON were calculated for all subjects and stratified based on MRI result. RESULTS: Two hundred fifty-one subjects had MRI results within 2 months of their initial ON ICD code (49 positive MRI [previously reported]; 202 negative MRI). Among those with negative MRI, 32 (16%) had aON, 40 (20%) had prior ON, 19 (9%) considered ON as a diagnosis, 92 (46%) had other confirmed diagnoses, and 19 (9%) had unknown diagnosis at time of code. Considering all subjects, accuracy for ICD code was 25% for acute ON, 41% for acute or prior ON, and 48% for acute, prior, or considered ON. Positive MRI, increased number of ON ICD codes, a code given by an ophthalmologist or neurologist within 2 months, and the presence of a neurology encounter within 2 months were associated with an increased accuracy for clinical aON diagnosis. CONCLUSIONS: In the setting of an MRI within 2 months, ICD codes for ON have low accuracy for acute ON and only slightly better accuracy for acute or prior ON. Accuracy is higher for cases with a positive MRI than those with a negative MRI, suggesting positive MRI in conjunction with ICD codes may help more accurately identify cases. Reliance on ICD and Current Procedural Terminology codes alone to identify aON cases may introduce substantial misclassification bias in claims-based research.

Atypical Presentations of Extraparenchymal Neurocysticercosis.

BACKGROUND: Neurocysticercosis (NCC) is the most common parasitic infection of the central nervous system and is typically diagnosed through visualization of the cysts in the cerebral parenchyma by neuro-imaging. However, neuro-imaging may not detect extraparenchymal neurocysticercosis (EPNCC), which is a rare manifestation of the disease involving the subarachnoid, meningeal, and intraventricular spaces. We report 2 cases of extraparenchymal neurocysticercosis, and discuss the diagnostic challenges and management of this entity. METHODS: Two cases were identified through clinical records. RESULTS: Both patients had an insidious onset with slow progression of disease, and presented with papilledema and cerebrospinal fluid (CSF) eosinophilia. One case was diagnosed with spinal cord biopsy. The other was diagnosed with CSF serology and next-generation sequencing-based pathogen analysis. Both patients were treated with ventriculoperitoneal shunt, systemic antiparasitic agents, and immunosuppression. CONCLUSIONS: EPNCC is less common than parenchymal NCC. A high level of clinical suspicion is required given its rarity, long incubation period, and slow progression. Diagnosis and treatment can be challenging and requires a multidisciplinary approach.

Tele-Neuro-Ophthalmology Utilization, Availability, and Attitudes: Update 1 Year Into the COVID-19 Public Health Emergency.

BACKGROUND: Telehealth was rapidly adopted early in the COVID-19 pandemic as a way to provide medical care while reducing risk of SARS-CoV2 transmission. Since then, telehealth utilization has evolved differentially according to subspecialty. This study assessed changes in neuro-ophthalmology during the first year of the COVID-19 pandemic. METHODS: Telehealth utilization and opinions pre-COVID-19, early pandemic (spring 2020), and 1 year later (spring 2021) were surveyed among practicing neuro-ophthalmologists in and outside the United States using an online platform. Demographics, self-reported utilization, perceived benefits, barriers, and examination suitability were collected over a 2-week period in May 2021. RESULTS: A total of 135 practicing neuro-ophthalmologists (81.5% United States, 47.4% females, median age 45-54 years) completed the survey. The proportion of participants using video visits remained elevated during COVID + 1 year (50.8%) compared with pre-COVID (6%, P < 0.0005, McNemar), although decreased compared with early COVID (67%, P < 0.0005). Video visits were the most commonly used methodology. The proportion of participants using remote testing (42.2% vs 46.2%), virtual second opinions (14.5% vs 11.9%, P = 0.45), and eConsults (13.5% vs 16.2%, P = 0.38) remained similar between early and COVID + 1 year ( P = 0.25). The majority selected increased access to care, better continuity of care, and enhanced patient appointment efficiency as benefits, whereas reimbursement, liability, disruption of in-person clinic flow, limitations of video examinations, and patient technology use were barriers. Many participants deemed many neuro-ophthalmic examination elements unsuitable when collected during a live video session, although participants believed some examination components could be evaluated adequately through a review of ancillary testing or outside records. CONCLUSIONS: One year into the COVID-19 pandemic, neuro-ophthalmologists maintained telemedicine utilization at rates higher than prepandemic levels. Tele-neuro-ophthalmology remains a valuable tool in augmenting patient care.

High Altitude as a Risk Factor for the Development of Nonarteritic Anterior Ischemic Optic Neuropathy.

BACKGROUND: Episodic high-altitude exposure leads to optic disc edema and retinopathy. It is uncertain whether high-altitude exposure is a risk factor for nonarteritic anterior ischemic optic neuropathy (NAION). METHODS: We performed a single-center, retrospective, cross-sectional case study of 5 patients with high-altitude-associated NAION (HA-NAION) from April 2014 to April 2019. Main study parameters included known vascular risk factors for NAION, evolution of visual acuity, visual field, optic disc, and macula measurements. RESULTS: We studied 5 eyes of 5 patients with HA-NAION that occurred at 7,000-9,000 ft above sea level, 28 patients with classic NAION that developed at sea level (normal altitude NAION or NA-NAION), and 40 controls. All 5 patients with HA-NAION had clinically confirmed NAION by a neuro-ophthalmologist within 3-21 days of onset and comprehensive follow-up evaluations (average follow-up of 23 months). Other than high-altitude exposure, 4 of 5 patients had undiagnosed obstructive sleep apnea (OSA, apnea-hypopnea index 5.4-22.2) and 1 had systemic vascular risk factors. All patients had disc-at-risk in the contralateral eye. The best-corrected distance visual acuity was 20/20 to 20/70 (median logMAR 0) at presentation and 20/70 to counting finger (median logMAR 0) at ≥6 months. Automated static perimetry revealed average mean deviation of -18.6 dB at presentation and -22.1 dB at ≥6 months. The average retinal nerve fiber layer was 244 µm (80-348 µm) at onset and 59 µm (55-80 µm) at ≥6 months. The average ganglion cell complex thickness was 50 µm (43-54 µm) at onset and 52 µm (50-55 µm) at ≥6 months. The patients with OSA were started on home continuous positive airway pressure treatment. Visual outcomes were similar in patients with HA-NAION and NA-NAION. - After addressing all NAION risk factors, no new events occurred in the HA-NAION group within 2-8 years with or without repeat high-altitude exposure. CONCLUSIONS: NAION can occur under high-altitude conditions. HA-NAION is associated with relatively younger age at onset, disc-at-risk, and OSA. These patients exhibit a relatively progressive course of vision loss after initial onset and severe thinning of optic nerves on optical coherence tomography. Treatment for OSA is recommended, especially with repeated high-altitude exposure.

Incidence, risk factors and ophthalmic clinical characteristic of ethambutol-induced optic neuropathy: 7-year experience.

Background: The purpose of this research was to investigate the characteristics, clinical manifestations, incidence, and risk factors in ethambutol-induced optic neuropathy (EON) in the Thai population. Methods: Patients treated with ethambutol for tuberculosis (TB) were retrospectively identified in the medical record of a tertiary hospital in Thailand from January 2012 to August 2019. Development of EON was determined through review of ophthalmology records. Comparison was made between patients with EON and those without EON to identify possible risk factors. Ophthalmic outcomes were characterized. Results: Among 4,141 patients who received ethambutol for TB treatment, 1,062 had an ophthalmology encounter, and 20 (0.5% overall, 1.88% with ophthalmology encounters) developed EON. In unadjusted analysis, compared to patients without EON, those with EON had a similar daily dose, but longer duration of ethambutol treatment (P=0.02). They were older (mean 43.74 vs. 58.60 years, P=0.001), more likely to have hypertension (P=0.02) and smoke (p=0.01). There were no differences in gender, body mass index, diabetes, dyslipidemia, HIV infection or glomerular filtration rate. The peripapillary retinal nerve fiber layer, ganglion cell analysis, and vascular density as measured using retinal optical coherence tomography were impacted by EON. In adjusted logistic regression analysis, age greater than 60 (OR = 8.71, p = 0.01) and smoking (OR = 7.06, p = 0.01) were independent risk factors for EON. Conclusion: In patients treated with ethambutol, the incidence proportion of EON was 0.5% among those with ethambutol administered and 1.88% among those with ethambutol and an eye visit. Potential EON risk factors were age, hypertension, smoking, and duration of ethambutol medication. Smoking has not been associated with EON in prior studies.