Application of a Deep Learning System to Detect Papilledema on Nonmydriatic Ocular Fundus Photographs in an Emergency Department

PURPOSE

The Fundus photography vs Ophthalmoscopy Trial Outcomes in the Emergency Department (FOTO-ED) studies showed that ED providers poorly recognized funduscopic findings in patients in the ED. We tested a modified version of the Brain and Optic Nerve Study Artificial Intelligence (BONSAI) deep learning system on nonmydriatic fundus photographs from the FOTO-ED studies to determine if the deep learning system could have improved the detection of papilledema had it been available to ED providers as a real-time diagnostic aid.

DESIGN

Retrospective secondary analysis of a cohort of patients included in the FOTO-ED studies.

METHODS

The testing data set included 1608 photographs obtained from 828 patients in the FOTO-ED studies. Photographs were reclassified according to the optic disc classification system used by the deep learning system ("normal optic discs," "papilledema," and "other optic disc abnormalities"). The system's performance was evaluated by calculating the area under the receiver operating characteristic curve (AUC), sensitivity, and specificity using a 1-vs-rest strategy, with reference to expert neuro-ophthalmologists.

RESULTS

The BONSAI deep learning system successfully distinguished normal from abnormal optic discs (AUC 0.92 [95% confidence interval {CI} 0.90-0.93]; sensitivity 75.6% [73.7%-77.5%] and specificity 89.6% [86.3%-92.8%]), and papilledema from normal and others (AUC 0.97 [0.95-0.99]; sensitivity 84.0% [75.0%-92.6%] and specificity 98.9% [98.5%-99.4%]). Six patients with missed papilledema in 1 eye were correctly identified by the deep learning system as having papilledema in the other eye.

CONCLUSIONS

The BONSAI deep learning system was able to reliably identify papilledema and normal optic discs on nonmydriatic photographs obtained in the FOTO-ED studies. Our deep learning system has excellent potential as a diagnostic aid in EDs and non-ophthalmology clinics equipped with nonmydriatic fundus cameras. NOTE: Publication of this article is sponsored by the American Ophthalmological Society.

Applying the 2022 optic neuritis criteria to noninflammatory optic neuropathies with optic nerve T2-hyperintensity: an observational study

INTRODUCTION

Recent diagnostic criteria for optic neuritis include T2-hyperintensity of the optic nerve (ON), even without associated contrast enhancement. However, isolated ON-T2-hyperintensity is a nonspecific finding found in any optic neuropathy or severe retinopathy. We applied the 2022 optic neuritis diagnostic criteria to a cohort of patients with noninflammatory optic neuropathy and ON-T2-hyperintensity in at least one eye, to assess the rate of optic neuritis misdiagnosis using these criteria.

METHODS

Retrospective study of consecutive patients who underwent brain/orbit MRI with/without contrast between 07/01/2019 and 06/30/2022. Patients with ON-T2-hyperintensity in at least one eye were included. The 2022 optic neuritis diagnostic criteria were applied to patients with noninflammatory optic neuropathies who had an ophthalmologic examination available for review.

RESULTS

Of 150 patients included, 85/150 had compressive optic neuropathy; 32/150 had glaucoma; 12/150 had papilledema; 8/150 had hereditary (3), radiation-induced (3), nutritional (1), traumatic (1) optic neuropathies (none fulfilled the criteria); 13/150 had ischemic optic neuropathy and 4 fulfilled the criteria as definite optic neuritis due to contrast enhancement of the ON head. Seven additional patients would have satisfied the diagnostic criteria if red flags for alternative diagnoses had been overlooked.

DISCUSSION

The application of the 2022 optic neuritis diagnostic criteria in patients with noninflammatory optic neuropathy and ON-T2-hyperintensity in at least one ON resulted in misdiagnosis of optic neuritis in only 4 patients because of ON head enhancement, all with nonarteritic anterior ischemic optic neuropathy. Neuro-ophthalmologic evaluation and exclusion of the ON head as a location in the MRI criteria would have prevented optic neuritis misdiagnosis in our study.

The Increasing Burden of Emergency Department and Inpatient Consultations for "Papilledema"

BACKGROUND

Increasing incidence of idiopathic intracranial hypertension (IIH), overreported radiologic signs of intracranial hypertension, difficult access to outpatient neuro-ophthalmology services, poor insurance coverage, and medicolegal concerns have lowered the threshold for emergency department (ED) visits for "papilledema." Our objective was to examine referral patterns and outcomes of neuro-ophthalmology ED and inpatient consultations for concern for papilledema.

METHODS

At one university-based quaternary care center, all adults referred for "papilledema" over one year underwent a standardized ED "papilledema protocol." We collected patient demographics, final diagnoses, and referral patterns.

RESULTS

Over 1 year, 153 consecutive patients were referred for concern for papilledema. After papilledema protocol, 89 of 153 patients (58%) had bilateral optic disc edema, among whom 89% (79/89) had papilledema (intracranial hypertension). Of the 38 of 153 (25%) consultations for suspected disorder of intracranial pressure without previous fundus examination (Group 1), 74% (28/38) did not have optic disc edema, 21% (8/38) had papilledema, and 5% (2/38) had other causes of bilateral disc edema. Of the 89 of 153 (58%) consultations for presumed papilledema seen on fundus examination (Group 2), 58% (66/89) had confirmed papilledema, 17% (15/89) had pseudopapilledema, and 9% (8/89) had other causes of bilateral optic disc edema. Of the 26 of 153 (17%) patients with known IIH (Group 3), 5 had papilledema and 4 required urgent intervention. The most common diagnosis was IIH (58/79). Compared with IIH, patients with secondary causes of intracranial hypertension were older (P = 0.002), men (P < 0.001), not obese (P < 0.001), and more likely to have neurologic symptoms (P = 0.002).

CONCLUSION

Inpatient and ED consultations for "papilledema" are increasing. Of the 153 ED and inpatient neuro-ophthalmology consultations seen for "papilledema" over 1 year, one-third of patients with optic disc edema of unknown cause before presentation to our ED had new vision- or life-threatening disease, supporting the need for prompt identification and evaluation of optic disc edema in the ED. In the face of limited access to neuro-ophthalmologists, this study supports the need for emergency department access to expert eye-care evaluation or ocular fundus camera for prompt identification of optic disc edema and standardized evaluation for neurologic emergencies.

Therapeutic benefit of idebenone in patients with Leber hereditary optic neuropathy: The LEROS nonrandomized controlled trial

Leber hereditary optic neuropathy (LHON) is a mitochondrial disease leading to rapid and severe bilateral vision loss. Idebenone has been shown to be effective in stabilizing and restoring vision in patients treated within 1 year of onset of vision loss. The open-label, international, multicenter, natural history-controlled LEROS study (ClinicalTrials.gov NCT02774005) assesses the efficacy and safety of idebenone treatment (900 mg/day) in patients with LHON up to 5 years after symptom onset (N = 199) and over a treatment period of 24 months, compared to an external natural history control cohort (N = 372), matched by time since symptom onset. LEROS meets its primary endpoint and confirms the long-term efficacy of idebenone in the subacute/dynamic and chronic phases; the treatment effect varies depending on disease phase and the causative mtDNA mutation. The findings of the LEROS study will help guide the clinical management of patients with LHON.

Optic Nerve MRI T2-Hyperintensity: A Nonspecific Marker of Optic Nerve Damage

BACKGROUND

MRI abnormalities are common in optic neuropathies, especially on dedicated orbital imaging. In acute optic neuritis, optic nerve T2-hyperintensity associated with optic nerve contrast enhancement is the typical imaging finding. In chronic optic neuropathies, optic nerve T2-hyperintensity and atrophy are regularly seen. Isolated optic nerve T2-hyperintensity is often erroneously presumed to reflect optic neuritis, frequently prompting unnecessary investigations and neuro-ophthalmology consultations. Our goal was to determine the significance of optic nerve/chiasm T2-hyperintensity and/or atrophy on MRI.

METHODS

Retrospective study of consecutive patients who underwent brain/orbital MRI with/without contrast at our institution between July 1, 2019, and June 6, 2022. Patients with optic nerve/chiasm T2-hyperintensity and/or atrophy were included. Medical records were reviewed to determine the etiology of the T2-hyperintensity and/or atrophy.

RESULTS

Four hundred seventy-seven patients (698 eyes) were included [mean age 52 years (SD ±18 years); 57% women]. Of the 364 of 698 eyes with optic nerve/chiasm T2-hyperintensity without atrophy, the causes were compressive (104), inflammatory (103), multifactorial (49), glaucoma (21), normal (19), and other (68); of the 219 of 698 eyes with optic nerve/chiasm T2-hyperintensity and atrophy, the causes were compressive (57), multifactorial (40), inflammatory (38), glaucoma (33), normal (7), and other (44); of the 115 of 698 eyes with optic nerve/chiasm atrophy without T2-hyperintensity, the causes were glaucoma (34), multifactorial (21), inflammatory (13), compressive (11), normal (10), and other (26). Thirty-six eyes with optic nerve/chiasm T2-hyperintensity or atrophy did not have evidence of optic neuropathy or retinopathy on ophthalmologic examination, and 17 eyes had clinical evidence of severe retinopathy without primary optic neuropathy.

CONCLUSIONS

Optic nerve T2-hyperintensity or atrophy can be found with any cause of optic neuropathy and with severe chronic retinopathy. These MRI findings should not automatically prompt optic neuritis diagnosis, workup, and treatment, and caution is advised regarding their use in the diagnostic criteria for multiple sclerosis. Cases of incidentally found MRI optic nerve T2-hyperintensity and/or atrophy without a known underlying optic neuropathy or severe retinopathy are rare. Such patients should receive an ophthalmologic examination before further investigations.

Glaucoma as a cause of optic nerve abnormalities on magnetic resonance imaging

BACKGROUND/OBJECTIVES

To report a series of patients with glaucoma and optic nerve abnormalities on magnetic resonance imaging (MRI) in at least one-eye, and to determine whether these findings correlate with the severity of glaucoma.

PATIENTS AND METHODS

Retrospective study of all patients who underwent a brain/orbits MRI without and with contrast at our institution between 07/1/2019-6/30/2022. Patients with optic nerve T2-hyperintensity and/or MRI optic nerve atrophy in at least one-eye and a diagnosis of isolated glaucoma in at least one-eye were included. Demographic information, glaucoma clinical characteristics, glaucoma severity parameters, and MRI indication were collected.

RESULTS

Fifty-six patients (112 eyes) (age 65 years-old [range 26-88]; 70% male) had isolated bilateral glaucoma with at least one-eye MRI optic nerve abnormality. The indication for MRI was atypical/asymmetric glaucoma in 91% of patients. Of the 112 eyes, 23 had optic nerve T2-hyperintensity alone; 33 had both optic nerve T2-hyperintensity and MRI optic nerve atrophy; 34 had MRI optic nerve atrophy alone; and 22 did not have abnormal optic nerve MRI-findings. None had optic nerve enhancement. A statistically significant association between optic nerve T2-hyperintensity or MRI optic nerve atrophy and glaucoma severity parameters was found.

CONCLUSIONS

Glaucoma is a clinical diagnosis and MRI brain is usually not required, except in atypical or asymmetric cases. Optic nerve T2-hyperintensity and MRI optic nerve atrophy are nonspecific MRI-findings that can be found in severe glaucomatous optic nerves and should not systematically prompt investigations for another cause of optic neuropathy.

Characteristics of Vitamin A Deficiency Retinopathy at a Tertiary Referral Center in the United States

PURPOSE

To explore the risk factors and fundus imaging features of vitamin A deficiency retinopathy (VADR) in an academic tertiary referral center in Atlanta, GA, United States, and to propose guidance regarding diagnostic workup and management of affected patients.

DESIGN

Single-center retrospective case series.

SUBJECTS

Nine patients seen between 2015 and 2021 at the Emory Eye Center diagnosed with VADR.

METHODS

Retrospective chart review.

MAIN OUTCOME MEASURES

Baseline serum retinol level, Snellen visual acuity, multimodal fundus imaging findings, and electroretinography findings.

RESULTS

Nine patients, 4 (44.4%) female, with a median (range) age of 68 (50-75) years were identified. The most common underlying etiologies for vitamin A deficiency included history of gastrointestinal surgery (55.6%), liver disease (44.4%), and nutritional depletion due to low-quality diet (44.4%). Only 1 (11.1%) patient had a history of bariatric surgery. Four (44.4%) patients were on some form of vitamin A supplementation before the diagnosis of VADR. Median (range) serum retinol level was 0.06 (< 0.06-0.19) mg/L. All patients had macular subretinal hyperreflective deposits resembling subretinal drusenoid deposits, although in some cases, these were scant and sparsely distributed. Six eyes of 3 patients with longstanding deficiency had defects in the external limiting membrane (ELM). Three of these eyes additionally had macular areas of complete retinal pigment epithelium and outer retinal atrophy (cRORA). Full-field electroretinography demonstrated severe rod dysfunction and mild to moderate cone system dysfunction. Many findings of VADR were reversible with vitamin A repletion. However, all eyes with ELM defects or cRORA had persistence or continued growth of these lesions.

CONCLUSION

Vitamin A deficiency retinopathy is uncommon in the developed world. However, given that early intervention can lead to dramatic visual improvement and avoid potentially permanent retinal damage, retina specialists should be familiar with its clinical presentation. The presence of nyctalopia and subretinal hyperreflective deposits in a patient with a history of gastrointestinal surgery, liver disease, and/or poor diet can be suggestive of this diagnosis, even in the presence of ongoing vitamin A supplementation. Vitamin A supplementation can vary in route and dosage and can be tailored to the individual with serial testing of serum retinol.

FINANCIAL DISCLOSURE(S)

The authors have no proprietary or commercial interest in any materials discussed in this article.

The BONSAI (Brain and Optic Nerve Study with Artificial Intelligence) deep learning system can accurately identify pediatric papilledema on standard ocular fundus photographs

BACKGROUND

Pediatric papilledema often reflects an underlying severe neurologic disorder and may be difficult to appreciate, especially in young children. Ocular fundus photographs are easy to obtain even in young children and in nonophthalmology settings. The aim of our study was to ascertain whether an improved deep-learning system (DLS), previously validated in adults, can accurately identify papilledema and other optic disk abnormalities in children.

METHODS

The DLS was tested on mydriatic fundus photographs obtained in a multiethnic pediatric population (<17 years) from three centers (Atlanta-USA; Bucharest-Romania; Singapore). The DLS's multiclass classification accuracy (ie, normal optic disk, papilledema, disks with other abnormality) was calculated, and the DLS's performance to specifically detect papilledema and normal disks was evaluated in a one-vs-rest strategy using the AUC, sensitivity and specificity, with reference to expert neuro-ophthalmologists.

RESULTS

External testing was performed on 898 fundus photographs: 447 patients; mean age, 10.33 (231 patients ≤10 years of age; 216, 11-16 years); 558 normal disks, 254 papilledema, 86 other disk abnormalities. Overall multiclass accuracy of the DLS was 89.6% (range, 87.8%-91.6%). The DLS successfully distinguished "normal" from "abnormal" optic disks (AUC 0.99 [0.98-0.99]; sensitivity, 87.3% [84.9%-89.8%]; specificity, 98.5% [97.6%-99.6%]), and "papilledema" from "normal and other" (AUC 0.99 [0.98-1.0]; sensitivity, 98.0% [96.8%-99.4%]; specificity, 94.1% (92.4%-95.9%)].

CONCLUSIONS

Our DLS reliably distinguished papilledema from normal optic disks and other disk abnormalities in children, suggesting it could be utilized as a diagnostic aid for the assessment of optic nerve head appearance in the pediatric age group.

Neuro-ophthalmology Emergency Department and Inpatient Consultations at a Large Academic Referral Center

PURPOSE

Prompt neuro-ophthalmology consultation prevents diagnostic errors and improves patient outcomes. The scarcity of neuro-ophthalmologists means that the increasing outpatient demand cannot be met, prompting many emergency department (ED) referrals by non-neuro-ophthalmologists. We describe our quaternary care institution's ED and inpatient neuro-ophthalmology consultation patterns and patient outcomes.

DESIGN

Prospective observational study.

PARTICIPANTS

Consecutive neuro-ophthalmology ED and inpatient consultation requests over 1 year.

METHODS

We collected patient demographics, distance traveled, insurance status, referring provider details, consultation question, final diagnosis, complexity of consultation, time of consultation, and need for outpatient follow-up.

MAIN OUTCOME MEASURES

Consultation patterns and diagnoses, complexity, and follow-up.

RESULTS

Of 494 consecutive adult ED and inpatient neuro-ophthalmology consultations requested over 1 year, 241 of 494 consultations (49%) occurred at night or during weekends. Of ED consultations (322 of 494 [65%]), 127 of 322 consultations (39%) occurred during weekdays, 126 of 322 consultations (39%) occurred on weeknights, and 69 of 322 consultations (22%) occurred on weekends or holidays. Of 322 ED consultations, 225 of 322 consultations (70%) were patients who initially sought treatment in the ED with a neuro-ophthalmic chief symptom. Of the 196 patients sent to the ED by a health care professional, 148 patients (148/196 [76%]) were referred by eye care specialists (74 optometrists and 74 ophthalmologists). The most common ED referral questions were for papilledema (75 of 322 [23%]) and vision loss (72 of 322 [22%]). A total of 219 of 322 patients (68%) received a final active neuro-ophthalmic diagnosis, 222 of 322 patients (69%) were cases of high or very high complexity, and 143 of 322 patients (44%) required admission. Inpatient consultations (n = 172) were requested most frequently by hospitalists, including neurologists (71 of 172 [41%]) and oncologists (20 of 172 [12%]) for vision loss (43 of 172 [25%]) and eye movement disorders (36 of 172 [21%]) and by neurosurgeons (58 of 172 [33%]) for examination for mass or a preoperative evaluation (19 of 172 [11%]). An active neuro-ophthalmic diagnosis was confirmed in 67% of patients (116 of 172). Outpatient neuro-ophthalmology follow-up was required for 291 of 494 patients (59%).

CONCLUSIONS

Neuro-ophthalmology consultations are critical to the diagnosis and management in the hospital setting. In the face of a critical shortage of neuro-ophthalmologists, this study highlights the need for technological and diagnostic aids for greater outpatient access.

FINANCIAL DISCLOSURE(S)

Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Optometric Practice Patterns for Acute Central and Branch Retinal Artery Occlusion

BACKGROUND

Optometrists are often the first providers to evaluate patients with acute vision loss and are often the first to diagnose a central retinal artery occlusion (CRAO). How quickly these patients present to the optometrist, are diagnosed, and referred for evaluation are major factors influencing the possibility of acute therapeutic intervention. Our aim was to survey the U.S. optometric community to determine current optometric practice patterns for management of CRAO.

METHODS

An anonymous seven-question survey was emailed in 2020 to the 5,101 members of the American Academy of Optometry and the 26,502 members of the American Optometric Association.

RESULTS

Of 31,603 optometrists who were sent the survey, 1,926 responded (6.1%). Most respondents (1,392/1,919, 72.5%) worked in an optometry-predominant outpatient clinic and were less than 30 minutes from a certified stroke center (1,481/1,923, 77.0%). Ninety-eight percent (1,884/1,922) of respondents had diagnosed less than 5 CRAOs in the previous year, and 1,000/1,922 (52.0%) had not diagnosed a CRAO in the prior year. Of the optometrists who diagnosed at least one CRAO in the previous year, 661/922 (71.7%) evaluated these patients more than 4 hours after the onset of vision loss. Optometrists who diagnosed a CRAO or branch retinal artery occlusion referred patients to an emergency department (ED) affiliated with a certified stroke center (844/1,917, 44.0%), an outpatient ophthalmology clinic (764/1,917, 39.9%), an ED without a stroke center (250/1,917, 13.0%), an outpatient neurology clinic (20/1,917, 1.0%), or other (39/1,917, 2.0%); most (22/39, 56.4%) who responded "other" would refer to a primary care physician.

CONCLUSIONS

Optometrists are likely the first providers to evaluate patients with acute vision loss, including from a retinal artery occlusion. However, only 6.1% of optometrists responded to our survey despite 2 reminder emails, likely reflecting the lack of exposure to acute retinal artery occlusions, and a potential lack of interest of optometrists in participating in research. Of the optometrists who reported evaluating a CRAO in the previous year, less than 29% saw the patient within 4 hours of vision loss. In addition, a large portion of optometrists are referring acute CRAO patients to outpatient ophthalmology clinics, delaying appropriate acute management. Therefore, it is imperative that optometrists and ophthalmologists are educated to view acute retinal arterial ischemia as an acute stroke and urgently refer these patients to an ED affiliated with a stroke center. The delay in patient presentation and these referral patterns make future clinical trials for acute CRAO challenging.

Seizures as the Initial Manifestation of Idiopathic Intracranial Hypertension Spectrum Disorder

Idiopathic intracranial hypertension (IIH) is a syndrome of isolated elevated intracranial pressure of unknown aetiology. The IIH spectrum has evolved over the past decade making the diagnosis and management more challenging. The neurological examination in IIH is typically normal except for papilloedema and possible cranial nerve 6 palsy. Recent publications have highlighted skull base thinning and remodelling in patients with chronic IIH. Resulting skull base defects can cause meningo-encephalocoeles, which are potential epileptogenic foci. We describe the clinical and radiological characteristics of five IIH patients with seizures and meningo-encephalocoeles as the presenting manifestations of IIH spectrum disorder.

Race Distribution in Nonarteritic Anterior Ischemic Optic Neuropathy

PURPOSE

To describe the racial distribution of patients diagnosed with nonarteritic anterior ischemic optic neuropathy (NAION) in 2 large urban academic centers in the United States.

DESIGN

Retrospective cross-sectional study.

METHODS

All patients with NAION evaluated between 2014 and 2022 in tertiary neuro-ophthalmology services in Atlanta, GA, and New York, NY, respectively, were included. In order to assess the racial accessibility to our services, similar numbers of patients with idiopathic intracranial hypertension seen in the same services were included. Self-reported race at the time of neuro-ophthalmologic examination was collected for all patients. Results were compared with data published by the US Bureau of Census for Decennial Census in 2020 for the states of Georgia and New York, and for the total population of the United States.

RESULTS

In both locations, the vast majority of patients with NAION reported being White (91.06% in Atlanta and 78.9% in New York). Only 7.27% of patients in Atlanta and 3% in New York reported being Black, and 1.24% of patients in Atlanta and 5.9% in New York reported being Asian. There were a much higher proportion of White people among NAION patients than in the group of patients with idiopathic intracranial hypertension and in each respective state and in the United States.

CONCLUSIONS

Our results show that the majority of patients with NAION are White, followed by Black and Asian races, respectively, thus confirming the NAION race distribution reported by past clinical trials.

The expanding spectrum of idiopathic intracranial hypertension

Once considered a rare and often difficult diagnosis in the era predating routine MRI, idiopathic intracranial hypertension has become an everyday concern in ophthalmology and neurology clinics where, especially in the latter, essentially every young overweight woman with headaches is initially presumed to have IIH. Has the diagnosis of IIH become too easy, and are we over-diagnosing IIH in this period of an accelerating obesity crisis? Or are we actually missing cases of IIH because they do not fit the classic clinical profile? We think it is both: at the same time IIH is being diagnosed in excess in obese women without papilledema, often resulting in unnecessary procedures, inappropriate treatment and even iatrogenic complications, the spectrum of this disorder is expanding to include a broad array of clinical presentations that involve multiple specialists beyond just the ophthalmologist and neurologist.

Deep Learning System Outperforms Clinicians in Identifying Optic Disc Abnormalities

BACKGROUND

The examination of the optic nerve head (optic disc) is mandatory in patients with headache, hypertension, or any neurological symptoms, yet it is rarely or poorly performed in general clinics. We recently developed a brain and optic nerve study with artificial intelligence-deep learning system (BONSAI-DLS) capable of accurately detecting optic disc abnormalities including papilledema (swelling due to elevated intracranial pressure) on digital fundus photographs with a comparable classification performance to expert neuro-ophthalmologists, but its performance compared to first-line clinicians remains unknown.

METHODS

In this international, cross-sectional multicenter study, the DLS, trained on 14,341 fundus photographs, was tested on a retrospectively collected convenience sample of 800 photographs (400 normal optic discs, 201 papilledema and 199 other abnormalities) from 454 patients with a robust ground truth diagnosis provided by the referring expert neuro-ophthalmologists. The areas under the receiver-operating-characteristic curves were calculated for the BONSAI-DLS. Error rates, accuracy, sensitivity, and specificity of the algorithm were compared with those of 30 clinicians with or without ophthalmic training (6 general ophthalmologists, 6 optometrists, 6 neurologists, 6 internists, 6 emergency department [ED] physicians) who graded the same testing set of images.

RESULTS

With an error rate of 15.3%, the DLS outperformed all clinicians (average error rates 24.4%, 24.8%, 38.2%, 44.8%, 47.9% for general ophthalmologists, optometrists, neurologists, internists and ED physicians, respectively) in the overall classification of optic disc appearance. The DLS displayed significantly higher accuracies than 100%, 86.7% and 93.3% of clinicians (n = 30) for the classification of papilledema, normal, and other disc abnormalities, respectively.

CONCLUSIONS

The performance of the BONSAI-DLS to classify optic discs on fundus photographs was superior to that of clinicians with or without ophthalmic training. A trained DLS may offer valuable diagnostic aid to clinicians from various clinical settings for the screening of optic disc abnormalities harboring potentially sight- or life-threatening neurological conditions.

Diagnosis of Optic Disc Oedema: Fundus Features, Ocular Imaging Findings, and Artificial Intelligence

Optic disc swelling is a manifestation of a broad range of processes affecting the optic nerve head and/or the anterior segment of the optic nerve. Accurately diagnosing optic disc oedema, grading its severity, and recognising its cause, is crucial in order to treat patients in a timely manner and limit vision loss. Some ocular fundus features, in light of a patient's history and visual symptoms, may suggest a specific mechanism or aetiology of the visible disc oedema, but current criteria can at most enable an educated guess as to the most likely cause. In many cases only the clinical evolution and ancillary testing can inform the exact diagnosis. The development of ocular fundus imaging, including colour fundus photography, fluorescein angiography, optical coherence tomography, and multimodal imaging, has provided assistance in quantifying swelling, distinguishing true optic disc oedema from pseudo-optic disc oedema, and differentiating among the numerous causes of acute optic disc oedema. However, the diagnosis of disc oedema is often delayed or not made in busy emergency departments and outpatient neurology clinics. Indeed, most non-eye care providers are not able to accurately perform ocular fundus examination, increasing the risk of diagnostic errors in acute neurological settings. The implementation of non-mydriatic fundus photography and artificial intelligence technology in the diagnostic process addresses these important gaps in clinical practice.

Understanding the molecular basis and pathogenesis of hereditary optic neuropathies: towards improved diagnosis and management

Hereditary optic neuropathies result from defects in the human genome, both nuclear and mitochondrial. The two main and most recognised phenotypes are dominant optic atrophy and Leber hereditary optic neuropathy. Advances in modern molecular diagnosis have expanded our knowledge of genotypes and phenotypes of inherited disorders that affect the optic nerve, either alone or in combination, with various forms of neurological and systemic degeneration. A unifying feature in the pathophysiology of these disorders appears to involve mitochondrial dysfunction, suggesting that the retinal ganglion cells and their axons are especially susceptible to perturbations in mitochondrial homoeostasis. As we better understand the pathogenesis behind these genetic diseases, aetiologically targeted therapies are emerging and entering into clinical trials, including treatments aimed at halting the cascade of neurodegeneration, replacing or editing the defective genes or their protein products, and potentially regenerating damaged optic nerves, as well as preventing generational disease transmission.

Indirect Comparison of Lenadogene Nolparvovec Gene Therapy Versus Natural History in Patients with Leber Hereditary Optic Neuropathy Carrying the m.11778G>A MT-ND4 Mutation

INTRODUCTION

Lenadogene nolparvovec is a promising novel gene therapy for patients with Leber hereditary optic neuropathy (LHON) carrying the m.11778G>A ND4 mutation (MT-ND4). A previous pooled analysis of phase 3 studies showed an improvement in visual acuity of patients injected with lenadogene nolparvovec compared to natural history. Here, we report updated results by incorporating data from the latest phase 3 trial REFLECT in the pool, increasing the number of treated patients from 76 to 174.

METHODS

The visual acuity of 174 MT-ND4-carrying patients with LHON injected in one or both eyes with lenadogene nolparvovec from four pooled phase 3 studies (REVERSE, RESCUE and their long-term extension trial RESTORE; and REFLECT trial) was compared to the spontaneous evolution of an external control group of 208 matched patients from 11 natural history studies.

RESULTS

Treated patients showed a clinically relevant and sustained improvement in their visual acuity when compared to natural history. Mean improvement versus natural history was - 0.30 logMAR (+ 15 ETDRS letters equivalent) at last observation (P < 0.01) with a maximal follow-up of 3.9 years after injection. Most treated eyes were on-chart as compared to less than half of natural history eyes at 48 months after vision loss (89.6% versus 48.1%; P < 0.01) and at last observation (76.1% versus 44.4%; P < 0.01). When we adjusted for covariates of interest (gender, age of onset, ethnicity, and duration of follow-up), the estimated mean gain was - 0.43 logMAR (+ 21.5 ETDRS letters equivalent) versus natural history at last observation (P < 0.0001). Treatment effect was consistent across all phase 3 clinical trials. Analyses from REFLECT suggest a larger treatment effect in patients receiving bilateral injection compared to unilateral injection.

CONCLUSION

The efficacy of lenadogene nolparvovec in improving visual acuity in MT-ND4 LHON was confirmed in a large cohort of patients, compared to the spontaneous natural history decline. Bilateral injection of gene therapy may offer added benefits over unilateral injection.

TRIAL REGISTRATION NUMBERS

NCT02652780 (REVERSE); NCT02652767 (RESCUE); NCT03406104 (RESTORE); NCT03293524 (REFLECT); NCT03295071 (REALITY).

A Deep Learning System for Automated Quality Evaluation of Optic Disc Photographs in Neuro-Ophthalmic Disorders

The quality of ocular fundus photographs can affect the accuracy of the morphologic assessment of the optic nerve head (ONH), either by humans or by deep learning systems (DLS). In order to automatically identify ONH photographs of optimal quality, we have developed, trained, and tested a DLS, using an international, multicentre, multi-ethnic dataset of 5015 ocular fundus photographs from 31 centres in 20 countries participating to the Brain and Optic Nerve Study with Artificial Intelligence (BONSAI). The reference standard in image quality was established by three experts who independently classified photographs as of "good", "borderline", or "poor" quality. The DLS was trained on 4208 fundus photographs and tested on an independent external dataset of 807 photographs, using a multi-class model, evaluated with a one-vs-rest classification strategy. In the external-testing dataset, the DLS could identify with excellent performance "good" quality photographs (AUC = 0.93 (95% CI, 0.91-0.95), accuracy = 91.4% (95% CI, 90.0-92.9%), sensitivity = 93.8% (95% CI, 92.5-95.2%), specificity = 75.9% (95% CI, 69.7-82.1%) and "poor" quality photographs (AUC = 1.00 (95% CI, 0.99-1.00), accuracy = 99.1% (95% CI, 98.6-99.6%), sensitivity = 81.5% (95% CI, 70.6-93.8%), specificity = 99.7% (95% CI, 99.6-100.0%). "Borderline" quality images were also accurately classified (AUC = 0.90 (95% CI, 0.88-0.93), accuracy = 90.6% (95% CI, 89.1-92.2%), sensitivity = 65.4% (95% CI, 56.6-72.9%), specificity = 93.4% (95% CI, 92.1-94.8%). The overall accuracy to distinguish among the three classes was 90.6% (95% CI, 89.1-92.1%), suggesting that this DLS could select optimal quality fundus photographs in patients with neuro-ophthalmic and neurological disorders affecting the ONH.

Optic neuritis and autoimmune optic neuropathies: advances in diagnosis and treatment

Optic neuritis is an inflammatory optic neuropathy that is commonly indicative of autoimmune neurological disorders including multiple sclerosis, myelin-oligodendrocyte glycoprotein antibody-associated disease, and neuromyelitis optica spectrum disorder. Early clinical recognition of optic neuritis is important in determining the potential aetiology, which has bearing on prognosis and treatment. Regaining high-contrast visual acuity is common in people with idiopathic optic neuritis and multiple sclerosis-associated optic neuritis; however, residual deficits in contrast sensitivity, binocular vision, and motion perception might impair vision-specific quality-of-life metrics. In contrast, recovery of visual acuity can be poorer and optic nerve atrophy more severe in individuals who are seropositive for antibodies to myelin oligodendrocyte glycoprotein, AQP4, and CRMP5 than in individuals with typical optic neuritis from idiopathic or multiple-sclerosis associated optic neuritis. Key clinical, imaging, and laboratory findings differentiate these disorders, allowing clinicians to focus their diagnostic studies and optimise acute and preventive treatments. Guided by early and accurate diagnosis of optic neuritis subtypes, the timely use of high-dose corticosteroids and, in some instances, plasmapheresis could prevent loss of high-contrast vision, improve contrast sensitivity, and preserve colour vision and visual fields. Advancements in our knowledge, diagnosis, and treatment of optic neuritis will ultimately improve our understanding of autoimmune neurological disorders, improve clinical trial design, and spearhead therapeutic innovation.

Ocular Optical Coherence Tomography in the Evaluation of Sellar and Parasellar Masses: A Review

Compression of the anterior visual pathways by sellar and parasellar masses can produce irreversible and devastating visual loss. Optical coherence tomography (OCT) is a noninvasive high-resolution ocular imaging modality routinely used in ophthalmology clinics for qualitative and quantitative analysis of optic nerve and retinal structures, including the retinal ganglion cells. By demonstrating structural loss of the retinal ganglion cells whose axons form the optic nerve before decussating in the optic chiasm, OCT imaging of the optic nerve and retina provides an excellent tool for detection and monitoring of compressive optic neuropathies and chiasmopathies due to sellar and parasellar masses. Recent studies have highlighted the role of OCT imaging in the diagnosis, follow-up, and prognostication of the visual outcomes in patients with chiasmal compression. OCT parameters of optic nerve and macular scans such as peripapillary retinal nerve fiber layer thickness and macular ganglion cell thickness are correlated with the degree of visual loss; additionally, OCT can detect clinically significant optic nerve and chiasmal compression before visual field loss is revealed on automated perimetry. Preoperative values of OCT optic nerve and macular parameters represent a prognostic tool for postoperative visual outcome. This review provides a qualitative analysis of the current applications of OCT imaging of the retina and optic nerve in patients with anterior visual pathway compression from sellar and parasellar masses. We also review the role of new technologies such as OCT-angiography, which could improve the prognostic ability of OCT to predict postoperative visual function.

Safety of Lenadogene Nolparvovec Gene Therapy Over 5 Years in 189 Patients With Leber Hereditary Optic Neuropathy

PURPOSE

To evaluate the safety profile of lenadogene nolparvovec (Lumevoq) in patients with Leber hereditary optic neuropathy.

DESIGN

Pooled analysis of safety data from 5 clinical studies.

METHODS

A total of 189 patients received single unilateral or bilateral intravitreal injections of a recombinant adeno-associated virus 2 (rAAV2/2) vector encoding the human wild-type ND4 gene. Adverse events (AEs) were collected throughout the studies, up to 5 years. Intraocular inflammation and increased intraocular pressure (IOP) were ocular AEs of special interest. Other assessments included ocular examinations, vector bio-dissemination, and systemic immune responses against rAAV2/2.

RESULTS

Almost all patients (95.2%) received 9 × 10¹⁰ viral genomes and 87.8% had at least 2 years of follow-up. Most patients (75.1%) experienced at least one systemic AE, but systemic treatment-related AEs occurred in 3 patients; none were serious. Intraocular inflammation was reported in 75.6% of lenadogene nolparvovec-treated eyes. Almost all intraocular inflammations occurred in the anterior chamber (58.8%) or in the vitreous (40.3%), and were of mild (90.3%) or moderate (8.8%) intensity; most resolved with topical corticosteroids alone. All IOP increases were mild to moderate in intensity. No AE led to study discontinuation. Bio-dissemination of lenadogene nolparvovec and systemic immune response were limited. The safety profile was comparable for patients treated bilaterally and unilaterally.

CONCLUSIONS

Lenadogene nolparvovec had a good overall safety profile with excellent systemic tolerability, consistent with limited bio-dissemination. The product was well tolerated, with mostly mild ocular side effects responsive to conventional ophthalmologic treatments.

Developments in the Treatment of Leber Hereditary Optic Neuropathy

PURPOSEOF REVIEW

To outline the current landscape of treatments for Leber hereditary optic neuropathy (LHON) along the therapeutic delivery pipeline, exploring the mechanisms of action and evidence for these therapeutic approaches.

RECENT FINDINGS

Treatments for LHON can be broadly classified as either mutation-specific or mutation-independent. Mutation-specific therapies aim to correct the underlying mutation through the use of a gene-editing platform or replace the faulty mitochondrial DNA-encoded protein by delivering the wild-type gene using a suitable vector. Recent gene therapy clinical trials assessing the efficacy of allotopically expressed MT-ND4 for the treatment of LHON due to the m.11778G > A mutation in MT-ND4 have shown positive results when treated within 12 months of symptom onset. Mutation-independent therapies can have various downstream targets that aim to improve mitochondrial respiration, reduce mitochondrial stress, inhibit or delay retinal ganglion cell apoptosis, and/or promote retinal ganglion cell survival. Idebenone, a synthetic hydrosoluble analogue of co-enzyme Q₁₀ (ubiquinone), is the only approved treatment for LHON. Mutation-independent approaches to gene therapy under pre-clinical investigation for other neurodegenerative disorders may have the potential to benefit patients with LHON. Although approved treatments are presently limited, innovations in gene therapy and editing are driving the expansion of the therapeutic delivery pipeline for LHON.

Intracranial computed tomography histogram analysis detects changes in the setting of elevated intracranial pressure and normal imaging

BACKGROUND

Patients with idiopathic intracranial hypertension (IIH) have elevated intracranial pressure (ICP) of unclear etiology. This study evaluated the ability of quantitative intracranial Hounsfield unit (HU) histogram analysis to detect pathophysiological changes from elevated ICP in the setting of a normal head CT.

METHODS

Retrospective analysis of non-contrast-enhanced head CT images of IIH patients and matched controls. Following skull stripping, total intracranial CT voxels within the range of 0-70 HU were divided into seven 10 HU bins. A measurement of total intracranial HU was also calculated for each patient. Imaging studies for IIH patients were reviewed for features of IIH including transverse sinus stenosis (TSS). Histogram measures were compared between IIH and control groups and correlated with imaging and clinical data.

RESULTS

Fourteen IIH patients with CSF opening pressure ≥25 cm water, and 31 age-, sex-, and ethnicity-matched controls were included. Compared to controls, IIH patients had a significantly greater proportion of voxels in the 40-50, 50-60, and 60-70 HU bins (p = 0.003, 0.001, and 0.003, respectively) but similar proportion in the 0-10 HU range. Severity of TSS significantly correlated with total intracranial HU measures. 50-60 HU and 60-70 HU bins demonstrated high AUCs of 0.81 and 0.80, respectively, in differentiating IIH from normal status.

CONCLUSION

Idiopathic intracranial hypertension patients have a greater proportion of high intracranial HU voxels representing blood volume, which may be explained by TSS causing venous congestion. The pattern provides further insights into the pathophysiology of IIH and may be useful for detecting elevated ICP in the setting of normal head CT imaging.

Cat scratch disease: What to do with the cat?

Purpose

Cat scratch disease (CSD) frequently has ophthalmologic manifestations. The ophthalmologist's approach to treating neuroretinitis is familiar, but few eye care providers are comfortable answering the next question of “what do I do with my cat?” Published guidelines are often vague in answering the complexities of real-life conundrums that can lead patients and their doctors to believe that risk mitigation should involve removal of the animal. Here, we present demonstrative scenarios informed by clinical practice and provide updated recommendations.

Observations

A 10-year-old boy presented with reduced vision in the right eye. Funduscopic examination identified optic nerve head edema with subretinal fluid, and a macular star developed one week later, consistent with the diagnosis of neuroretinitis. Serology confirmed Bartonella henselae antibodies and a diagnosis of CSD. The father disclosed that the family has recently adopted three kittens, who have scratched the boy and the patient's younger sister. The physician and patient's family find themselves at a loss regarding best practices for what should be done with the kittens.

Conclusions and Importance

B. henselae has been detected in a variety of mammals and can be transmitted via vectors such as fleas. Even well-appearing animals can transmit the bacteria, months to years after their initial infection. Symptoms, clinical and laboratory findings will depend on bacterial load and strain virulence, as well as the physiological/immunological status of the host, with people at the extremes of age and the immunocompromised being at greater disease risk. Flea control is crucial to minimize transmission risk. Our veterinary expert (EBB) recommends testing (with serology and PCR) and treating infected animals (with doxycycline and a quinolone). Patients should be counseled to speak with their pets’ veterinarian. When addressing the concerns of our CSD patients in clinical practice, ophthalmologists should be aware of the strategies for minimizing Bartonella transmission risk, and cognizant of the One Health approach for managing zoonoses.

Randomized trial of bilateral gene therapy injection for m.11778G > A MT-ND4 Leber optic neuropathy

Leber hereditary optic neuropathy (LHON) is an important example of mitochondrial blindness with the m.11778G > A mutation in the MT-ND4 gene being the most common disease-causing mitochondrial DNA (mtDNA) variant worldwide. The REFLECT phase 3 pivotal study is a randomized, double-masked, placebo-controlled trial investigating the efficacy and safety of bilateral intravitreal injection of lenadogene nolparvovec in patients with a confirmed m.11778G > A mutation, using a recombinant adeno-associated virus vector 2, serotype 2 (rAAV2/2-ND4). The first-affected eye received gene therapy; the fellow (affected/not-yet-affected) eye was randomly injected with gene therapy or placebo. The primary endpoint was the difference in change from baseline of best-corrected visual acuity (BCVA) in second-affected/not-yet-affected eyes treated with lenadogene nolparvovec versus placebo at 1.5 years post-treatment, expressed in logarithm of the minimal angle of resolution (LogMAR). Forty-eight patients were treated bilaterally and 50 unilaterally. At 1.5 years, the change from baseline in BCVA was not statistically different between second-affected/not-yet-affected eyes receiving lenadogene nolparvovec and placebo (primary endpoint). A statistically significant improvement in BCVA was reported from baseline to 1.5 years in lenadogene nolparvovec-treated eyes: -0.23 LogMAR for the first-affected eyes of bilaterally treated patients (p < 0.01); and -0.15 LogMAR for second-affected/not-yet-affected eyes of bilaterally treated patients and the first-affected eyes of unilaterally treated patients (p < 0.05). The mean improvement in BCVA from nadir to 1.5 years was -0.38 (0.052) LogMAR and -0.33 (0.052) LogMAR in first-affected and second-affected/not-yet-affected eyes treated with lenadogene nolparvovec, respectively (bilateral treatment group). A mean improvement of -0.33 (0.051) LogMAR and -0.26 (0.051) LogMAR was observed in first-affected lenadogene nolparvovec-treated eyes and second-affected/not-yet-affected placebo-treated eyes, respectively (unilateral treatment group). The proportion of patients with one or both eyes on-chart at 1.5 years was 85.4% and 72.0% for bilaterally and unilaterally treated patients, respectively. The gene therapy was well tolerated, with no systemic issues. Intraocular inflammation, which was mostly mild and well controlled with topical corticosteroids, occurred in 70.7% of lenadogene nolparvovec-treated eyes versus 10.2% of placebo-treated eyes. Among eyes treated with lenadogene nolparvovec, there was no difference in the incidence of intraocular inflammation between bilaterally and unilaterally treated patients. Overall, the REFLECT trial demonstrated an improvement of BCVA in LHON eyes carrying the m.11778G > A mtDNA mutation treated with lenadogene nolparvovec or placebo to a degree not reported in natural history studies and supports an improved benefit/risk profile for bilateral injections of lenadogene nolparvovec relative to unilateral injections.

Study design and baseline characteristics for the reflect gene therapy trial ofm.11778g>A/ND4-LHON

Objective

REFLECT is the first randomised, double-masked, placebo-controlled multicentre phase 3 clinical trial that evaluated the efficacy and safety of bilateral intravitreal (IVT) injection of lenadogene nolparvovec in subjects with Leber hereditary optic neuropathy carrying the m.11778G>A mutation.

Methods and analysis

A total of 98 subjects were enrolled with vision loss of ≤12 months. The subjects were randomised to one of two treatment arms with all subjects receiving an intravitreal (IVT) injection of lenadogene nolparvovec in their first affected eye and the second-affected eye randomised to receive IVT of either lenadogene nolparvovec or placebo.

Results

The majority of subjects were male with a mean duration of vision loss of 8.3 months. All but one subject experienced bilateral loss of vision at the time of injection. The mean best-corrected visual acuity of first-affected eyes was worse compared with second/not-yet-affected eyes. Analysis of retinal anatomical parameters showed increased thinning in the first-affected eyes when compared with the second/not-yet-affected eyes with both treatment arms showing significant changes compared with unaffected individuals.

Conclusion

The REFLECT trial is the third and the largest phase 3 clinical study evaluating lenadogene nolparvovec in m.11778G>A Leber hereditary optic neuropathy (LHON) subjects. The observed demographics in REFLECT are consistent with previous reports in LHON subjects in the acute and dynamic phases of LHON disease. Combined with the visual function and anatomical parameters obtained in the previous RESCUE and REVERSE trials, REFLECT has provided a uniformly collected data set that should help direct future LHON clinical trials.

Ischemic Optic Neuropathies: Current Concepts

Ischemic optic neuropathy (ION) is the term ascribed to optic nerve disease that is the result of a transient or permanent interruption of the blood supply to any portion of the optic nerve. Anterior ischemic optic neuropathy (AION) refers to ischemia of the optic nerve head, whereas posterior ischemic optic neuropathy (PION) indicates ischemia of the posterior optic nerve. IONs are primarily classified as arteritic ION and non-arteritic ION. A subset of ION that occurs around the time of surgery is termed peri-operative ION. These phenomena will be discussed as distinct entities.

Carotid-Cavernous Fistula Presenting as Isolated Painful Anisocoria

A painful isolated third nerve palsy is an uncommon presenting sign of a carotid-cavernous fistula (CCF). It mostly occurs in dural CCFs with posterior drainage into the petrosal sinuses. We present a case of a 50-year-old woman who developed acute right periorbital facial pain in the territory of the first branch of the right trigeminal nerve and was noted to have a right dilated unreactive pupil with very subtle right ptosis. She was subsequently diagnosed with a posteriorly draining dural CCF.

Artificial intelligence in ophthalmology: an insight into neurodegenerative disease

PURPOSE OF REVIEW

The aging world population accounts for the increasing prevalence of neurodegenerative diseases such as Alzheimer's and Parkinson's which carry a significant health and economic burden. There is therefore a need for sensitive and specific noninvasive biomarkers for early diagnosis and monitoring. Advances in retinal and optic nerve multimodal imaging as well as the development of artificial intelligence deep learning systems (AI-DLS) have heralded a number of promising advances of which ophthalmologists are at the forefront.

RECENT FINDINGS

The association among retinal vascular, nerve fiber layer, and macular findings in neurodegenerative disease is well established. In order to optimize the use of these ophthalmic parameters as biomarkers, validated AI-DLS are required to ensure clinical efficacy and reliability. Varied image acquisition methods and protocols as well as variability in neurogenerative disease diagnosis compromise the robustness of ground truths that are paramount to developing high-quality training datasets.

SUMMARY

In order to produce effective AI-DLS for the diagnosis and monitoring of neurodegenerative disease, multicenter international collaboration is required to prospectively produce large inclusive datasets, acquired through standardized methods and protocols. With a uniform approach, the efficacy of resultant clinical applications will be maximized.

Retinal and optic nerve magnetic resonance diffusion-weighted imaging in acute non-arteritic central retinal artery occlusion

OBJECTIVES

Diffusion weighted imaging hyperintensity (DWI-H) has been described in the retina and optic nerve during acute central retinal artery occlusion (CRAO). We aimed to determine whether DWI-H can be accurately identified on standard brain magnetic resonance imaging (MRI) in non-arteritic CRAO patients at two tertiary academic centers.

MATERIALS AND METHODS

Retrospective cross-sectional study that included all consecutive adult patients with confirmed acute non-arteritic CRAO and brain MRI performed within 14 days of CRAO. At each center, two neuroradiologists masked to patient clinical data reviewed each MRI for DWI-H in the retina and optic nerve, first independently then together. Statistical analysis for inter-rater reliability and correlation with clinical data was performed.

RESULTS

We included 204 patients [mean age 67.9±14.6 years; 47.5% females; median time from CRAO to MRI 1 day (IQR 1-4.3); 1.5 T in 127/204 (62.3%) and 3.0 T in 77/204 (37.7%)]. Inter-rater reliability varied between centers (κ = 0.27 vs. κ = 0.65) and was better for retinal DWI-H. Miss and error rates significantly differed between neuroradiologists at each center. After consensus review, DWI-H was identified in 87/204 (42.6%) patients [miss rate 117/204 (57.4%) and error rate 11/87 (12.6%)]. Significantly more patients without DWI-H had good visual acuity at follow-up (p = 0.038).

CONCLUSIONS

In this real-world case series, differences in agreement and interpretation accuracy among neuroradiologists limited the role of DWI-H in diagnosing acute CRAO on standard MRI. DWI-H was identified in 42.6% of patients and was more accurately detected in the retina than in the optic nerve. Further studies are needed with standardized novel MRI protocols.

Absence of lenadogene nolparvovec DNA in a brain tumor biopsy from a patient in the REVERSE clinical study, a case report

BACKGROUND

Leber Hereditary Optic Neuropathy (LHON) is a rare, maternally-inherited mitochondrial disease that primarily affects retinal ganglion cells (RGCs) and their axons in the optic nerve, leading to irreversible, bilateral severe vision loss. Lenadogene nolparvovec gene therapy was developed as a treatment for patients with vision loss from LHON caused by the most prevalent m.11778G > A mitochondrial DNA point mutation in the MT-ND4 gene. Lenadogene nolparvovec is a replication-defective recombinant adeno-associated virus vector 2 serotype 2 (AAV2/2), encoding the human wild-type MT-ND4 protein. Lenadogene nolparvovec was administered by intravitreal injection (IVT) in LHON patients harboring the m.11778G > A ND4 mutation in a clinical development program including one phase 1/2 study (REVEAL), three phase 3 pivotal studies (REVERSE, RESCUE, REFLECT), and one long-term follow-up study (RESTORE, the follow-up of REVERSE and RESCUE patients).

CASE PRESENTATION

A 67-year-old woman with MT-ND4 LHON, included in the REVERSE clinical study, received a unilateral IVT of lenadogene nolparvovec in the right eye and a sham injection in the left eye in May 2016, 11.4 months and 8.8 months after vision loss in her right and left eyes, respectively. The patient had a normal brain magnetic resonance imaging with contrast at the time of diagnosis of LHON. Two years after treatment administration, BCVA had improved in both eyes. The product was well tolerated with mild and resolutive anterior chamber inflammation in the treated eye. In May 2019, the patient was diagnosed with a right temporal lobe glioblastoma, IDH-wildtype, World Health Organization grade 4, based on histological analysis of a tumor excision. The brain tumor was assessed for the presence of vector DNA by using a sensitive validated qPCR assay targeting the ND4 sequence of the vector.

CONCLUSION

ND4 DNA was not detected (below 15.625 copies/μg of genomic DNA) in DNA extracted from the brain tumor, while a housekeeping gene DNA was detected at high levels. Taken together, this data shows the absence of detection of lenadogene nolparvovec in a brain tumor (glioblastoma) of a treated patient in the REVERSE clinical trial 3 years after gene therapy administration, supporting the long-term favorable safety of lenadogene nolparvovec.

Prognostic Value of the Neurological Pupil Index in Patients With Acute Subarachnoid Hemorrhage

BACKGROUND

The Neurological Pupil index (NPi) provides a quantitative assessment of pupil reactivity and may have prognostic value in patients with subarachnoid hemorrhage (SAH). We aimed to explore associations between the NPi and clinical outcomes in patients with SAH.

METHODS

A retrospective analysis of 79 consecutive patients with acute SAH. Age, sex, Acute Physiology and Chronic Health Evaluation-II score, and respiratory failure and NPi in each eye were recorded at admission. The primary outcomes included death and poor clinical outcome (defined as inpatient death, care withdrawal, or discharge Glasgow Outcome Score <4). Groups were compared using the Fisher exact test, and predictive models developed with fast-and-frugal trees (FFTs).

RESULTS

A total of 53 patients were included: 21 (40%) had poor clinical outcomes and 2 (4%) died. Univariate analysis found that only APACHE-II score (P < 0.001) and respiratory failure (P = 0.04) were significantly associated with poor clinical outcomes. NPi was lower among patients with poor clinical outcomes (mean 4.3 in the right eye and 4.2 in the left eye) vs those without (mean 4.5 in the right eye and 4.5 in the left eye), but neither was significant. However, the most accurate FFTs for death and poor clinical outcome included NPi after accounting for age in the death FFT and APACHE-II score in the poor outcome FFT (sensitivity [sn] = 100%, specificity [sp] = 94%, and accuracy (ac) = 94% in a model for death; sn = 100%, sp = 50%, and ac = 70%) in a model for poor clinical outcome.

CONCLUSIONS

Our study supports the NPi as a useful prognostic marker for poor outcomes in acute SAH after accounting for age and APACHE-II score.

Biodistribution of intravitreal lenadogene nolparvovec gene therapy in nonhuman primates

Lenadogene nolparvovec (Lumevoq) gene therapy was developed to treat Leber hereditary optic neuropathy (LHON) caused by the m.11778G > A in MT-ND4 that affects complex I of the mitochondrial respiratory chain. Lenadogene nolparvovec is a replication-defective, single-stranded DNA recombinant adeno-associated virus vector 2 serotype 2, containing a codon-optimized complementary DNA encoding the human wild-type MT-ND4 subunit protein. Lenadogene nolparvovec was administered by unilateral intravitreal injection in MT-ND4 LHON patients in two randomized, double-masked, and sham-controlled phase III clinical trials (REVERSE and RESCUE), resulting in bilateral improvement of visual acuity. These and other earlier results suggest that lenadogene nolparvovec may travel from the treated to the untreated eye. To investigate this possibility further, lenadogene nolparvovec was unilaterally injected into the vitreous body of the right eye of healthy, nonhuman primates. Viral vector DNA was quantifiable in all eye and optic nerve tissues of the injected eye and was detected at lower levels in some tissues of the contralateral, noninjected eye, and optic projections, at 3 and 6 months after injection. The results suggest that lenadogene nolparvovec transfers from the injected to the noninjected eye, thus providing a potential explanation for the bilateral improvement of visual function observed in the LHON patients.

Referral Patterns of Central Retinal Artery Occlusion to an Academic Center Affiliated With a Stroke Center

BACKGROUND

Central retinal artery occlusion (CRAO) is a medical emergency, and patients who present acutely should be immediately referred to the nearest stroke center. We evaluated practice patterns for CRAO management at one academic center over the last decade.

METHODS

This was a retrospective study on all adult patients diagnosed with a CRAO seen at one tertiary hospital and outpatient clinic affiliated with a comprehensive stroke center ("our institution") from 2010 to 2020. Our electronic medical records were searched for CRAO diagnoses, and patient medical records were reviewed. The exclusion criteria were incorrect diagnosis, unclear diagnosis, historical CRAO, or satellite clinic location. Demographics, distance and time to presentation to our institution, number and type of prior providers seen, diagnostic tests performed, and treatments provided were collected. Summary statistics of median, mean, and frequency were calculated and reported with measures of variance (interquartile range [IQR], ranges). F, Tukey, and Fisher exact tests were used for comparisons.

RESULTS

We included 181 patients with a diagnosis of CRAO (80 [44.2%] women; median age 69 years [range 20-101]). The median distance from patient's home to our institution was 27.8 miles (IQR 15.5-57.4; range 2.4-930). The median time from visual loss to presentation at our institution was 144 hours (IQR 23-442 hours, range 0.5-2,920) from 2010 to 2013, 72 hours (IQR 10.5-372 hours, range 0-13,140) from 2014 to 2016, and 48 hours (IQR 7-180 hours, range 0-8,030) from 2017 to 2020 (P = 0.07). 91/181 (50%) patients presented to an outpatient provider. 73/181 (40%) presented to an emergency department. Eighty-six percent presented within 1 week of visual loss onset, and rates of comprehensive inpatient evaluation for acute CRAO improved from 44% in 2010-2013 to 82% in 2017-2020 (P < 0.01).

CONCLUSIONS

Patients with CRAO often present late and only after evaluation by multiple outpatient providers. Improvement has occurred over the past decade, but delays underscore the barriers to performing clinical trials evaluating very acute treatments for CRAO. Educational interventions for healthcare providers and patients are necessary.

Unilateral Isolated Paucisymptomatic Optic Disc Edema

BACKGROUND

Unilateral isolated optic disc edema (UIODE) represents a challenging clinical presentation that frequently precipitates an extensive diagnostic work-up. Patients without an apparent diagnosis despite appropriate investigations are often categorized as having "papillophlebitis," an entity that is poorly defined in the existing literature. Our aim was to describe the characteristics of a series of patients with paucisymptomatic UIODE, determine the optimal diagnostic approach to such cases, and clarify the clinical features of presumed papillophlebitis.

METHODS

We retrospectively identified 29 patients with UIODE who were seen by neuro-ophthalmologists at a single center between 2005 and 2019. Each patient presented with isolated, unilateral disc edema that was either entirely asymptomatic or associated with minimal visual symptoms. Patients underwent a comprehensive neuro-ophthalmic evaluation and several ophthalmic and systemic investigations. Data from the initial visit and all subsequent clinical visits were collected, including patient demographics, examination findings, and details of the diagnostic work-up.

RESULTS

Our 29 patients with UIODE were found to have a variety of underlying diagnoses including unilateral papilledema due to idiopathic intracranial hypertension (10 patients), optic nerve sheath meningioma (5), incipient nonarteritic anterior ischemic neuropathy (4), vitreopapillary traction (3), orbital masses (2), a peripapillary choroidal neovascular membrane (1), and presumed papillophlebitis (4). The duration of disc edema varied considerably based on the etiology, but most patients had favorable visual outcomes.

CONCLUSIONS

A systematic approach to the evaluation of UIODE, combined with long-term follow-up, led to a definite diagnosis in a majority of patients, with only 4 patients presumed to have papillophlebitis, a diagnosis the actual existence of which remains controversial.

Prediction of Postoperative Risk of Raised Intracranial Pressure After Spontaneous Skull Base Cerebrospinal Fluid Leak Repair

BACKGROUND

A relationship between idiopathic intracranial hypertension and spontaneous skull base cerebrospinal fluid (CSF) leaks has been proposed, by which CSF leak decreases intracranial pressure (ICP) and masks the symptoms and signs of elevated ICP. These patients are at risk of developing papilledema, symptoms of elevated ICP, or a recurrent CSF leak after CSF leak repair. The objective of this study was to assess whether radiographic signs of raised ICP on preoperative magnetic resonance or computed venography (MRI or CTV) are predictors of postoperative papilledema, recurrence of CSF leak, or need for CSF shunt surgery.

METHODS

We performed a retrospective review of systematically collected demographics, fundus examination, and presurgical brain MRI and magnetic resonance venography/computed tomography venography (MRV/CTV) in patients seen at 1 institution between 2013 and 2019 with spontaneous skull base CSF leak repair. Patients were divided into 2 groups depending on whether they developed papilledema, recurrent CSF leak, or required CSF shunting (Group 1) or not (Group 2).

RESULTS

Fifty-seven patients were included, among whom 19 were in Group 1. There was no difference in demographic characteristics or clinical features between patients in Group 1 and Group 2. Controlling for other imaging features, bilateral transverse venous sinus stenosis (TVSS) on preoperative imaging increased the odds of being in Group 1 by 4.2 times (95% confidence interval [CI], 1.04-21.2, P = 0.04), optic nerve tortuosity decreased the odds of being in Group 1 by 8.3 times (95% CI: 1.4-74.6, P = 0.02).

CONCLUSION

Imaging of the intracranial venous system with MRV or CTV is warranted before repair of spontaneous CSF leak, as bilateral TVSS is an independent risk factor for postoperative papilledema, CSF leak recurrence, or need for a CSF shunting procedure.

Long-Term Follow-Up After Unilateral Intravitreal Gene Therapy for Leber Hereditary Optic Neuropathy: The RESTORE Study

BACKGROUND

RESCUE and REVERSE were 2 Phase 3 clinical trials that assessed the efficacy and safety of intravitreal gene therapy with lenadogene nolparvovec (rAAV2/2-ND4) for the treatment of Leber hereditary optic neuropathy (LHON). RESTORE is the long-term follow-up study of subjects treated in the RESCUE and REVERSE trials.

METHODS

In RESCUE and REVERSE, 76 subjects with LHON because of the m.11778 G>A mutation in the mitochondrial gene ND4 received a single unilateral intravitreal injection of lenadogene nolparvovec. After 96 weeks, 61 subjects were enrolled in the long-term follow-up study RESTORE. The best-corrected visual acuity (BCVA) was assessed over a period of up to 52 months after onset of vision loss. A locally estimated scatterplot smoothing regression model was used to analyze changes in BCVA over time. Vision-related quality of life was reported using the visual function questionnaire-25 (VFQ-25).

RESULTS

The population of MT-ND4 subjects enrolled in RESTORE was representative of the combined cohorts of RESCUE and REVERSE for mean age (35.1 years) and gender distribution (79% males). There was a progressive and sustained improvement of BCVA up to 52 months after the onset of vision loss. The final mean BCVA was 1.26 logarithm of the minimal angle of resolution 48 months after the onset of vision loss. The mean VFQ-25 composite score increased by 7 points compared with baseline.

CONCLUSION

The treatment effect of lenadogene nolparvovec on BCVA and vision-related quality of life observed 96 weeks (2 years) after treatment in RESCUE and REVERSE was sustained at 3 years in RESTORE, with a maximum follow-up of 52 months (4.3 years) after the onset of vision loss.

Cross-Sectional Analysis of Baseline Visual Parameters in Subjects Recruited Into the RESCUE and REVERSE ND4-LHON Gene Therapy Studies

OBJECTIVE

This report presents a cross-sectional analysis of the baseline characteristics of subjects with Leber hereditary optic neuropathy enrolled in the gene therapy trials RESCUE and REVERSE, to illustrate the evolution of visual parameters over the first year after vision loss.

METHODS

RESCUE and REVERSE were 2 phase III clinical trials designed to assess the efficacy of rAAV2/2-ND4 gene therapy in ND4-LHON subjects. At enrollment, subjects had vision loss for ≤6 months in RESCUE, and between 6 and 12 months in REVERSE. Functional visual parameters (best-corrected visual acuity [BCVA], contrast sensitivity [CS], and Humphrey Visual Field [HVF]) and structural parameters assessed by spectral-domain optical coherence tomography were analyzed in both cohorts before treatment. The cross-sectional analysis of functional and anatomic parameters included the baseline values collected in all eyes at 2 different visits (Screening and Inclusion).

RESULTS

Seventy-six subjects were included in total, 39 in RESCUE and 37 in REVERSE. Mean BCVA was significantly worse in RESCUE subjects compared with REVERSE subjects (1.29 and 1.61 LogMAR respectively, P = 0.0029). Similarly, mean CS and HVF were significantly more impaired in REVERSE vs RESCUE subjects (P < 0.005). The cross-sectional analysis showed that the monthly decrease in BCVA, ganglion cell layer macular volume, and retinal nerve fiber layer thickness was much more pronounced in the first 6 months after onset (+0.24 LogMAR, -0.06 mm3, and -6.00 μm respectively) than between 6 and 12 months after onset (+0.02 LogMAR, -0.01 mm3, and -0.43 μm respectively).

CONCLUSION

LHON progresses rapidly in the first months following onset during the subacute phase, followed by relative stabilization during the dynamic phase.

Acute Central Retinal Artery Occlusion Seen within 24 Hours at a Tertiary Institution

OBJECTIVE

Acute central retinal artery occlusion (CRAO) is an emergency with poor visual outcome. Intravenous thrombolysis within 4.5 h of vision loss is safe and may improve vision, but is rarely administered because of frequent delays in presentation. We describe a subgroup of CRAO patients presenting within 24 h of vision loss to a tertiary care center affiliated with a comprehensive stroke center.

MATERIALS AND METHODS

Retrospective review of 181 consecutive CRAO patients seen at our institution from 2010 to 2020.

RESULTS

Out of 181 CRAO patients, 62 (34%) presented within 24 h of vision loss and tended to live closer to the hospital. These patients were more likely to be admitted to the hospital and receive comprehensive stroke work-up compared to patients who presented after 24 h of vision loss. Patients presenting after 24 h did not necessarily receive prior appropriate work-up at outside institutions. Conservative treatments for CRAO were administered to 20/181 patients, and only 3 patients received intravenous thrombolysis.

CONCLUSIONS

Patients with CRAO do not present to the emergency department fast enough and diagnosis of CRAO is often delayed. Despite having a protocol in place, only 3/181 patients received IV thrombolysis, emphasizing the difficulty in administering very acute treatments for CRAO. Public education regarding CRAO is necessary to improve presentation times, management, and visual outcomes. Hospitals need to develop accelerated diagnostic pathway protocols for patients with acute vision loss so that CRAO patients may be diagnosed and be considered for potential acute treatments as quickly as possible.

Bilateral visual improvement with unilateral gene therapy injection for Leber hereditary optic neuropathy

REVERSE is a randomized, double-masked, sham-controlled, multicenter, phase 3 clinical trial that evaluated the efficacy of a single intravitreal injection of rAAV2/2-ND4 in subjects with visual loss from Leber hereditary optic neuropathy (LHON). A total of 37 subjects carrying the m.11778G>A (MT-ND4) mutation and with duration of vision loss between 6 to 12 months were treated. Each subject's right eye was randomly assigned in a 1:1 ratio to treatment with rAAV2/2-ND4 (GS010) or sham injection. The left eye received the treatment not allocated to the right eye. Unexpectedly, sustained visual improvement was observed in both eyes over the 96-week follow-up period. At week 96, rAAV2/2-ND4-treated eyes showed a mean improvement in best-corrected visual acuity (BCVA) of -0.308 LogMAR (+15 ETDRS letters). A mean improvement of -0.259 LogMAR (+13 ETDRS letters) was observed in the sham-treated eyes. Consequently, the primary end point, defined as the difference in the change in BCVA from baseline to week 48 between the two treatment groups, was not met (P = 0.894). At week 96, 25 subjects (68%) had a clinically relevant recovery in BCVA from baseline in at least one eye, and 29 subjects (78%) had an improvement in vision in both eyes. A nonhuman primate study was conducted to investigate this bilateral improvement. Evidence of transfer of viral vector DNA from the injected eye to the anterior segment, retina, and optic nerve of the contralateral noninjected eye supports a plausible mechanistic explanation for the unexpected bilateral improvement in visual function after unilateral injection.