Disease Course of Clinically Isolated Optic Neuritis.

BACKGROUND AND OBJECTIVES: Optic neuritis is the most common optic neuropathy in young adults and a frequent manifestation of multiple sclerosis. Its clinical course is pertinent to the design of visual pathway neuroprotection trials. METHODS: This is a secondary analysis of longitudinal data from the TONE trial, which included 103 patients from 12 German academic tertiary centers with acute unilateral optic neuritis as a clinically isolated syndrome and baseline high-contrast visual acuity <0.5 decimal. Patients were randomized to 1,000 mg methylprednisolone i.v./d plus either erythropoietin (33,000 IU/d) or placebo (saline solution) for 3 days. They were followed up at standardized intervals with a battery of tests including high-contrast visual acuity, low-contrast letter acuity, contrast sensitivity, visual fields, visual evoked potentials, and retinal optical coherence tomography. At 6 months, participants answered a standardized questionnaire on vision-related quality of life (NEI-VFQ 25). We describe the disease course with mixed-effects piecewise linear models and calculate structure-function correlations using Pearson r. Because erythropoietin had no effect on the visual system, we use pooled (treatment-agnostic) data. RESULTS: Patients experienced initial rapid and then decelerating improvements of visual function with thinning of inner and thickening of outer retinal layers. At 6 months, visual parameters were positively correlated with inner and negatively correlated with outer retinal thickness changes. Peripapillary retinal nerve fiber layer thinning predominantly occurred in sectors without previous swelling. At 6 months, macular ganglion cell and inner plexiform layer thinning was weakly correlated with the P100 peak time (r = -0.11) and moderately correlated with the amplitude of visual evoked potentials (r = 0.35). Only functional outcomes were at least moderately correlated with vision-related quality of life. DISCUSSION: The longitudinal data from this large study cohort may serve as a reference for the clinical course of acute optic neuritis. The pattern of correlation between visual evoked potentials and inner retinal thinning may argue that the latter is mostly due to ganglion cell loss, rather than dysfunction. Visual pathway neuroprotection trials with functional outcomes are needed to confirm that candidate drugs will benefit patients' vision-related quality of life. TRIAL REGISTRATION INFORMATION: ClinicalTrials.gov, NCT01962571.

Clinical profile and challenges faced in the management of optic neuritis: the Indian scenario.

PURPOSE: Optic neuritis (ON) is a relatively common ophthalmic disease that has recently received renewed attention owing to immunological breakthroughs. We studied the profile of patients with ON with special reference to antibody-mediated ON and the challenges faced in its management. METHODS: Case records of patients with ON presenting to a tertiary eye-care center in South India were analyzed. Data on demographics, presenting visual acuity (VA), clinical features, seropositivity for aquaporin-4 immunoglobulin G (AQP4-IgG) and myelin oligodendrocyte glycoprotein immunoglobulin G (MOG-IgG), details of magnetic resonance imaging (MRI) of orbits and brain, and treatment were collected. RESULTS: Among 138 cases with acute ON, male: female ratio was 1:2. Isolated ON was present in 41.3% of cases. Antibody testing of sera was performed in 68 patients only due to financial limitations. Among these, 48.5% were MOG-IgG-seropositive, 11.76% were AQP4-IgG-seropositive, and 30.88% samples were double seronegative. Other causes included multiple sclerosis (n = 4), lactational ON (n = 4), tuberculosis (n = 2), invasive perineuritis (n = 2), COVID-19 vaccination (n = 2), and COVID-19 (n = 1). The mean presenting best corrected visual acuity (BCVA) was 1.31 ± 1.16 logMAR (logarithm of the minimum angle of resolution). The mean BCVA at 3 months was 0.167 ± 0.46 logMAR. Only initial VA ≤ 'Counting fingers' (CF) had a significant association with the visual outcome for final VA worse than CF. The steep cost of investigations and treatment posed challenges for many patients in the management of ON. CONCLUSION: MOG-IgG-associated ON is common in India. Unfortunately, financial constraints delay the diagnosis and timely management of ON, adversely affecting the outcome.

Myelin oligodendrocyte glycoprotein (MOG) associated optic neuritis in a patient with idiopathic intracranial hypertension (IIH) and compressive optic neuropathy case report.

BACKGROUND: Myelin oligodendrocyte glycoprotein-associated disease (MOGAD) has a wide phenotypic expression and should be considered in a differential diagnosis of patients with optic disc edema and increased intracranial pressure because MOGAD can mimic IIH and compressive optic neuropathy. CASE PRESENTATION: A 53-year-old woman with a history of presumed idiopathic intracranial hypertension ("IIH") presented with new headache and visual loss. She had a BMI of 35.44 kg/m2 and a past medical history significant for depression, hepatitis C, hyperlipidemia, and uterine cancer post-hysterectomy. She had undergone multiple lumboperitoneal shunts for presumed IIH and had a prior pituitary adenoma resection. Her visual acuity was no light perception OD and counting fingers OS. After neuro-ophthalmic consultation, a repeat cranial MRI showed symmetric thin peripheral optic nerve sheath enhancement of the intra-orbital optic nerves OU. Serum MOG antibody was positive at 1:100 and she was treated with intravenous steroids followed by plasma exchange and rituximab. CONCLUSIONS: This case highlights the importance of considering MOGAD in the differential diagnosis of optic neuropathy. Although likely multifactorial, we believe that the lack of improvement in our case from presumed IIH and despite adequate neurosurgical decompression of a pituitary adenoma with compression of the optic apparatus reflected underlying unrecognized MOGAD. Clinicians should consider repeat imaging of the orbit (in addition to the head) in cases of atypical IIH or compressive optic neuropathy especially when the clinical course or response to therapy is poor or progressive.

The Efficacy, Adverse Effects and Economic Implications of Oral Versus Intravenous Methylprednisolone for the Treatment of Optic Neuritis: A Systematic Review.

INTRODUCTION: Optic neuritis may occur in a variety of conditions, including as a manifestation of multiple sclerosis. Despite significant research into the efficacy of corticosteroids as a first-line treatment, the optimal route of administration has not been well defined. This review aims to explore the efficacy, adverse effects and economic implications of using oral versus intravenous methylprednisolone to treat acute optic neuritis. METHODS: A systematic search of the databases PubMed/MEDLINE, Embase and CENTRAL was performed to July 2022, prior to data collection and risk of bias analysis in accordance with the PRISMA guidelines. RESULTS: Six articles fulfilled the inclusion criteria. The results showed that in the treatment of acute optic neuritis, oral methylprednisolone has a non-inferior efficacy and adverse effect profile in comparison to intravenous methylprednisolone. In a cost analysis, oral methylprednisolone to be more cost-effective than intravenous methylprednisolone. CONCLUSIONS: Oral methylprednisolone has comparable efficacy and adverse effect profiles to intravenous methylprednisolone for the treatment of optic neuritis. The analysis suggests oral administration is more cost-effective than intravenous administration; however, further analyses of the formal cost-benefit ratio are required.

Acriflavine, a HIF-1 inhibitor, preserves vision in an experimental autoimmune encephalomyelitis model of optic neuritis.

Introduction: Optic neuritis (ON) is often an early sign of multiple sclerosis (MS), and recent studies show a link between HIF-1 pathway activation and inflammation. This study aimed to determine if inhibition of the HIF-1 pathway using the HIF-1a antagonist acriflavine (ACF) can reduce clinical progression and rescue the ocular phenotype in an experimental autoimmune encephalomyelitis (EAE) ON model. Methods: EAE-related ON was induced in 60 female C57BL/6J mice by immunization with MOG33-55, and 20 EAE mice received daily systemic injections of ACF at 5 mg/kg. Changes in the visual function and structure of ACF-treated EAE mice were compared to those of placebo-injected EAE mice and naïve control mice. Results: ACF treatment improved motor-sensory impairment along with preserving visual acuity and optic nerve function. Analysis of retinal ganglion cell complex alsoshowed preserved thickness correlating with increased survival of retinal ganglion cells and their axons. Optic nerve cell infiltration and magnitude of demyelination were decreased in ACF-treated EAE mice. Subsequent in vitro studies revealed improvements not only attributed to the inhibition of HIF-1 butalso to previously unappreciated interaction with the eIF2a/ATF4 axis in the unfolded protein response pathway. Discussion: This study suggests that ACF treatment is effective in an animal model of MS via its pleiotropic effects on the inhibition of HIF-1 and UPR signaling, and it may be a viable approach to promote rehabilitation in MS.

SARS-CoV-2 Parainfectious Optic Neuropathy: 3 Case Reports and a Review of the Literature.

BACKGROUND: Parainfectious optic neuritis is an inflammatory reaction that occurs shortly after an infection without direct invasion by a pathogen. The clinical profile depends on the infectious organism. Cases of SARS-CoV-2 parainfectious optic neuritis have been reported in the literature, but there are no reviews that have applied strict inclusion criteria to more definitively establish the clinical profile associated with SARS-CoV-2. METHODS: We present 3 new cases of SARS-CoV-2 parainfectious optic neuritis. We also review the literature for definite cases by selecting only those with unambiguous clinical features and MRI findings of optic neuritis, positive SARS-CoV-2 polymerase chain reaction or serology, and the absence of myelin oligodendrocyte-glycoprotein or aquaporin-4 antibodies or other diseases associated with optic neuritis. RESULTS: We report 2 cases of monophasic, unilateral SARS-CoV-2 parainfectious optic neuritis with optic disc edema and nadir visual acuities of finger counting. We report 1 case of mild SARS-CoV-2 parainfectious optic neuritis that featured cotton wool spots, peripapillary wrinkles and hemorrhages, and recurrence after an initial steroid taper. We identified 6 cases of unambiguous SARS-CoV-2 parainfectious optic neuritis from the literature. Combining our case series with the case reports in the literature, the average age was 42.8 years, 3/9 had bilateral disease, 6/8 had optic disc edema, 8/9 had nadir visual acuity of finger counting or worse, and all recovered visual acuity to 20/40 or better after therapy with steroids. CONCLUSIONS: SARS-CoV-2 parainfectious optic neuritis has a clinical profile that is atypical for idiopathic optic neuritis but fairly typical of parainfectious forms of optic neuritis with a severely reduced nadir visual acuity, high likelihood of bilaterality, high incidence of optic disc edema, and prompt and significant response to corticosteroids. Further study with long-term follow-up and epidemiologic investigation will be needed to further characterize this clinical entity.

Myelin oligodendrocyte glycoprotein antibody-associated optic neuritis in a post-COVID-19 infection patient.

PURPOSE: SARS-CoV-2 viral infection affects multiple systems including the respiratory, gastrointestinal, neurological, cardiac, and ophthalmic systems. We report a case of myelin oligodendrocyte glycoprotein (MOG) related optic neuritis in a SARS-CoV-2 (COVID-19) patient. METHODS: Case report. RESULTS: A 36-year-old Malay gentleman with underlying hypertension presented with the first episode of bilateral progressively worsening blurred vision for 1 week associated with retrobulbar pain. There were no other neurological symptoms. He had fever a week before the eye symptoms and tested positive for COVID-19. He received COVID-19 booster vaccine a month before the disease onset. On examination, his vision was hand motion on right eye and 6/18 on left eye. Relative afferent pupillary defect (RAPD) was positive on right eye with abnormal optic nerve function tests. Anterior segments were unremarkable. Fundus examination showed bilateral optic disc swelling. MRI revealed multifocal hyperintense subcortical white matter lesions. Optic nerves appeared normal with no enhancement seen. Blood investigation showed a positive serum MOG antibody. Intravenous methylprednisolone was commenced followed by oral prednisolone after which his vision and ocular symptoms markedly improved. The oral prednisolone was tapered alongside addition of azathioprine. At 1 month, the disease was stable with no recurrence. CONCLUSION: While optic neuritis has been associated with both COVID-19 infection and vaccination, MOG IgG antibody-mediated optic neuritis is also a possible manifestation. This type of optic neuritis associated with COVID-19 infection does not show a similar pattern of frequent recurrences as seen in non-COVID-19 related optic neuritis.

[Combination of post-infectious optic neuritis and Guillain-Barré syndrome]. / Sochetanie postinfektsionnogo nevrita zritel'nykh nervov i sindroma Giiena­Barre.

The coexistence of optic neuritis and Guillain-Barré syndrome is a rare combination of neurological diseases. The trigger of an autoimmune inflammatory process is often a respiratory mycoplasma infection. Ignorance of such combination can lead to diagnostic and therapy mistakes. This article describes the case of a rare combination of overlapping optic neuritis and Guillain-Barré syndrome, associated with Mycoplasma pneumoniae and provides the short literature review. Further studies are required to identify common pathogenetic mechanisms of combined inflammatory lesions of the optic nerves and peripheral nervous system.

Toxic retrobulbar neuritis due to recurrent nonsteroidal antiinflammatory drug-exacerbated respiratory disease-based chronic sinusitis in the left sphenoid sinus: a case report.

BACKGROUND: Abrupt visual impairment constitutes a medical urgency, necessitating an interdisciplinary diagnostic and therapeutic approach owing to the broad spectrum of potential etiologies, thereby engaging numerous medical specialties. CASE PRESENTATION: A 21-year-old Mixed White and Asian female patient, with medical history of nonsteroidal antiinflammatory drug-exacerbated respiratory disease necessitating previous sinus surgery, reported sudden monocular vision loss. Unremarkable ophthalmological examination of the fellow eye and hematological parameters, save for a slight elevation in lymphocytes and eosinophils, were observed. Imaging studies indicated recurrence of bilateral chronic rhinosinusitis with nasal polyps and a mucocele in the left sphenoid sinus, accompanied by bony structural deficits. Emergency revision sinus surgery, guided by navigation, was promptly performed. The patient received treatment with methylprednisolone, ceftriaxone, cyanocobalamin, pyridoxine, thiamine, and acetylsalicylic acid. During the hospital stay, she developed steroid-induced glaucoma, which was subsequently managed successfully. Negative microbiological swabs, along with pathohistological evidence of increased tissue eosinophilia and the patient's clinical history, led to the diagnosis of toxic retrobulbar neuritis secondary to recurrent nonsteroidal antiinflammatory drug-exacerbated respiratory disease-associated chronic rhinosinusitis of the left sphenoid sinus. CONCLUSIONS: In cases of acute unilateral vision loss, optic neuritis is a highly probable differential diagnosis and may be induced by pathologies of the paranasal sinuses. Nonsteroidal antiinflammatory drug-exacerbated respiratory disease, a subtype of chronic rhinosinusitis, is associated with type 2 inflammation, which is increasingly recognized for its role in the pathogenesis of bronchial asthma, eosinophilic esophagitis, and atopic eczema. Clinicians should consider chronic rhinosinusitis as a potential differential diagnosis in unilateral visual loss and be cognizant of the rising significance of type 2 inflammations, which are relevant to a variety of diseases.

A Randomized Prospective Trial Comparing Repository Corticotropin Injection and Intravenous Methylprednisolone for Neuroprotection in Acute Optic Neuritis.

BACKGROUND: Repository corticotrophin injection (RCI, Acthar Gel) and intravenous methylprednisolone (IVMP) improve the rate but not the extent of visual recovery following acute optic neuritis. RCI has adrenal-stimulating and melanocortin receptor-stimulating properties that may endow it with unique anti-inflammatory properties relative to IVMP. METHODS: Individuals with acute optic neuritis of less than 2 weeks duration were prospectively enrolled and randomized 1:1 to receive either RCI or IVMP. Peripapillary retinal nerve fiber layer (pRNFL) and ganglion cell plus inner plexiform layer thickness (GC + IPL) were serially evaluated by OCT. In addition, patient-reported outcomes (PROs) for changes in fatigue, mood, visual function, depression, and quality of life (QOL) were measured, and high and low contrast visual acuity were recorded. RESULTS: Thirty-seven subjects were enrolled (19 RCI; 18 IVMP); the average time from symptom to treatment was 8.8 days. At 6 months, there was no difference in the primary outcome: loss of average pRNFL thickness in the affected eye (RCI vs IVMP: -13.1 vs -11.7 µm, P = 0.88) 6 months after randomization. Additional outcomes also showed no difference between treatment groups: 6-month attenuation of GC + IPL thickness (RCI vs IVMP: -13.8 vs -12.0 µm, P = 0.58) and frequency of pRNFL swelling at 1 month (RCI vs IVMP: 63% vs 72%, P = 0.73) and 3 months (RCI vs IVMP: 26% vs 31%, P = 0.99). Both treatments resulted in improvement in visual function and PROs. CONCLUSIONS: Treatment of acute optic neuritis with RCI or IVMP produced no clinically meaningful differences in optic nerve structure or visual function.

Clinical characteristics and prognosis of optic neuritis in Taiwan - a hospital-based cohort study.

BACKGROUND: Optic neuritis (ON) is an inflammatory disease of optic nerve. The distinct etiologies of ON significantly influence its clinical manifestation, neuroimaging findings, and visual outcomes. However, the clinical characteristics might be influenced by the racial differences. The purpose of this study is to investigate the clinical characteristics of various types of ON at a Taiwanese tertiary center. METHODS: This cohort study analyzed 163 patients who received treatment and continued following-up for ON between 2015 and 2022. We selected patients who had been tested for anti-aquaporin-4 antibody (AQP4-Ab) and anti-myelin oligodendrocyte glycoprotein antibody (MOG-Ab). The participants were classified into four groups on the basis of their etiologies, specifically (1) multiple sclerosis (MS)-related, (2) AQP4-Ab-positive, (3) MOG-Ab-positive, or (4) idiopathic ON. The researchers recorded the patients' clinical characteristics, treatment course, magnetic resonance imaging and optical coherence tomography (OCT) findings, and visual outcomes. RESULTS: MOG-Ab-positive group had higher percentages of disk swelling and pain with eye movement. Long optic nerve and perineural enhancement are the hallmarks of MOG-Ab-related ON. The ON relapse rate was higher in AQP4-Ab-positive group. Although members of AQP4-Ab-positive group received immediate steroid pulse therapy, these patients experienced the worst visual outcomes. Moreover, a thinner retinal nerve fiber layer (RNFL) was noted in AQP4-Ab-positive group. MS group had a higher incidence of extra-optic nerve lesions. Multivariate regression identified pretreatment visual acuity and RNFL thickness as the important factors affecting visual outcomes. CONCLUSIONS: This cohort study identified the clinical features of different types of ON. Patients with AQP4-Ab-positive ON had poorer visual outcomes, which may be attributed to multiple relapses and profound nerve damage, as revealed by OCT findings. Patients with MOG-Ab-positive ON displayed long optic nerve enhancement but had more favorable prognoses. Thus, antibody-based classification facilitates treatment and prognosis in ON.

Alleviating early demyelination in ischaemia/reperfusion by inhibiting sphingosine-1-phosphate receptor 2 could protect visual function from impairment.

Retinal ischaemia/reperfusion (I/R) injury is a common cause of retinal ganglion cell (RGC) apoptosis and axonal degeneration, resulting in irreversible visual impairment. However, there are no available neuroprotective and neurorestorative therapies for retinal I/R injury, and more effective therapeutic approaches are needed. The role of the myelin sheath of the optic nerve after retinal I/R remains unknown. Here, we report that demyelination of the optic nerve is an early pathological feature of retinal I/R and identify sphingosine-1-phosphate receptor 2 (S1PR2) as a therapeutic target for alleviating demyelination in a model of retinal I/R caused by rapid changes in intraocular pressure. Targeting the myelin sheath via S1PR2 protected RGCs and visual function. In our experiment, we observed early damage to the myelin sheath and persistent demyelination accompanied by S1PR2 overexpression after injury. Blockade of S1PR2 by the pharmacological inhibitor JTE-013 reversed demyelination, increased the number of oligodendrocytes, and inhibited microglial activation, contributing to the survival of RGCs and alleviating axonal damage. Finally, we evaluated the postoperative recovery of visual function by recording visual evoked potentials and assessing the quantitative optomotor response. In conclusion, this study is the first to reveal that alleviating demyelination by inhibiting S1PR2 overexpression may be a therapeutic strategy for retinal I/R-related visual impairment.

A comparative study of visual outcome in patients with optic neuritis treated with five or seven days of intravenous corticosteroid treatment.

BACKGROUND: Optic neuritis (ON), a major cause of visual impairment in young adults, is generally associated with rapid visual recovery when treated with intravenous methylprednisolone treatment (IVMPT). However, the optimal duration of such treatment is unknown, ranging from three to seven days in clinical practice. We aimed to compare the visual recovery in patients treated with 5-day or 7-day duration IVMPT. METHODS: We performed a retrospective cohort study of consecutive patients with ON in São Paulo, Brazil, from 2016 to 2021. We compared the proportion of participants with visual impairment in 5-day and 7-day treatment schedules at discharge, at 1 month and between 6 and 12 months after the diagnosis of ON. The findings were adjusted to age, severity of the visual impairment, co-intervention with plasma exchange, time from symptom onset to IVMPT and the etiology of the ON to mitigate indication bias. RESULTS: We included 73 patients with ON treated with 5 or 7-day duration of 1 g/d intravenous methylprednisolone therapy. Visual impairment at 6-12 months in the 5-day or the 7-day treatment groups was similar (57% x 59%, p > 0.9, Odds Ratio 1.03 [95% CI 0.59-1.84]). The results were similar after adjusting for prognostic variables and when observed at different time points. CONCLUSION: Visual recovery is similar in patients treated with 5-day and 7-day duration treatments of 1 g/day intravenous methylprednisolone, suggesting a ceiling effect. Limiting the duration of the treatment can reduce hospital stay and costs, without interfering with clinical benefit.

Predictors of Long-Term Visual Acuity in a Modern Cohort of Patients With Acute Idiopathic and Multiple Sclerosis-Associated Optic Neuritis.

BACKGROUND: For patients with idiopathic or multiple sclerosis (MS)-associated optic neuritis (ON), the largest multicenter clinical trial (Optic Neuritis Treatment Trial [ONTT]) showed excellent visual outcomes and baseline high-contrast visual acuity (HCVA) was the only predictor of HCVA at 1 year. We aimed to evaluate predictors of long-term HCVA in a modern, real-world population of patients with ON and compare with previously published ONTT models. METHODS: We performed a retrospective, longitudinal, observational study at the University of Michigan and the University of Calgary evaluating 135 episodes of idiopathic or MS-associated ON in 118 patients diagnosed by a neuro-ophthalmologist within 30 days of onset (January 2011-June 2021). Primary outcome measured was HCVA (Snellen equivalents) at 6-18 months. Multiple linear regression models of 107 episodes from 93 patients assessed the association between HCVA at 6-18 months and age, sex, race, pain, optic disc swelling, symptoms (days), viral illness prodrome, MS status, high-dose glucocorticoid treatment, and baseline HCVA. RESULTS: Of the 135 acute episodes (109 Michigan and 26 Calgary), median age at presentation was 39 years (interquartile range [IQR], 31-49 years), 91 (67.4%) were women, 112 (83.0%) were non-Hispanic Caucasians, 101 (75.9%) had pain, 33 (24.4%) had disc edema, 8 (5.9%) had a viral prodrome, 66 (48.9%) had MS, and 62 (46.6%) were treated with glucocorticoids. The median (IQR) time between symptom onset and diagnosis was 6 days (range, 4-11 days). The median (IQR) HCVA at baseline and at 6-18 months were 20/50 (20/22, 20/200) and 20/20 (20/20, 20/27), respectively; 62 (45.9%) had better than 20/40 at baseline and 117 (86.7%) had better than 20/40 at 6-18 months. In linear regression models (n = 107 episodes in 93 patients with baseline HCVA better than CF), only baseline HCVA (ß = 0.076; P = 0.027) was associated with long-term HCVA. Regression coefficients were similar and within the 95% confidence interval of coefficients from published ONTT models. CONCLUSIONS: In a modern cohort of patients with idiopathic or MS-associated ON with baseline HCVA better than CF, long-term outcomes were good, and the only predictor was baseline HCVA. These findings were similar to prior analyses of ONTT data, and as a result, these are validated for use in conveying prognostic information about long-term HCVA outcomes.

Case Report: Optic neuritis as the initial presentation of Orientia tsutsugamushi infection detected by metagenomic next-generation sequencing.

Scrub typhus is an acute febrile illness caused by Orientia tsutsugamushi infection, and typically manifested as fever, eschar, lymphadenopathy, rash, and other flu-like signs. Ocular involvement was not uncommon, and mostly occurred at post-fever or recovery stage in scrub typhus cases. We hereby report a case of scrub typhus presenting as unilateral optic neuritis (ON). A 56-year-old man going wild fishing nearly every day complained of a blurred vision and an inferior visual field defect in the right eye two or three days after an insect-bite like shin induration in his left leg. He was diagnosed as ON, and treated with dexamethasone in the local hospital. Unfortunately, his right eye vision progressively deteriorated during steroid therapy. Three days after steroid therapy ceased, he suffered from a high fever and painful subcutaneous masses in the left groin. Peripheral blood test by metagenomic next-generation sequencing (mNGS) was positive for Orientia tsutsugamushi, but negative for other pathogens. The diagnosis was then revised to scrub typhus and ON. His systemic symptoms rapidly disappeared after oral doxycycline and omadacycline therapy. However, his right eye vision continuously deteriorated to hand motion. Further serum tests for aquaporin 4-IgG antibody and myelin oligodendrocyte glycoprotein-IgG antibody were both negative, but for anticardiolipin IgM and beta-2-glycoprotein-I IgM were both positive. The patient's right eye vision gradually improved after doxycycline combined with steroid pulse therapy. Our case indicates that ON in scrub typhus cases may present as a parainfectious inflammation, and that mNGS is a useful and valuable method for early diagnosis of scrub typhus.

Retrobulbar Optic Neuritis Post Typhoid fever: Atypical Case Report.

Purpose: Post typhoid autoimmune-mediated simultaneous retrobulbar optic neuritis (RBN) involving both eyes is a rare complication requiring early diagnosis and prompt treatment. Case presentation: We present a case of bilateral RBN in a six-year-old male who came to our department with a chief complaint of sudden onset painless profound loss of vision in both eyes, after an episode of high-grade fever 2 weeks earlier. Perception of light was doubtful in right eye (RE) and vision was hand movement in left eye (LE). On ocular examination, anterior segment and fundoscopy of both eye were normal. Blood investigation was normal except for raised ESR. CT of brain and orbit was normal. MRI of brain and orbit revealed bilateral thickening and restriction of optic nerve suggestive of ON. He was initiated with intravenous methyl-prednisolone for three consecutive days after which tapering doses of oral corticosteroid was given. Results: A rapid and marked improvement in Uncorrected Visual Acuity (UCVA) was observed with UCVA improving to 6/ 12 RE and 6/ 9 LE post 1 month. The pupillary reaction also became normal in both eyes. Moreover, there was a significant reduction in the Widal titre of the patient post 2 weeks of treatment. Discussion: Paediatric ON has rare and unique characteristics, which differentiates it from adult ON. No clinical trials have been performed for paediatric ON, so current clinical practice follows the evidence drawn from the Optic Neuritis Treatment Trial (ONTT). Conclusion: Paediatric ON is uncommon. Despite having clinically severe bilateral vision loss, retrobulbar optic neuritis in children post typhoid fever has excellent response to steroid therapy if early diagnosed and treated. Abbreviations: RBN = Retrobulbar Optic Neuritis, MRI = Magnetic Resonance Imaging, CT = Computerized Tomography, UCVA = Uncorrected Visual Acuity, RE = Right eye, LE = Left eye, ON = Optic neuritis, ONTT = Optic Neuritis Treatment Trial.

Case Report: Severe Optic Neuritis after Multiple Episodes of Malaria in a Traveler to Africa.

Although local transmission of malaria has been eliminated, the disease is frequently imported to China by Chinese travelers returning from Africa. Optic neuritis (ON) is occasionally reported in malarial cases and usually shows good visual recovery and prognosis. Herein, we report severe visual loss with poor recovery due to bilateral ON in a malarial patient who traveled from Nigeria. While he was still in Nigeria, his visual acuity dropped to no light perception in both eyes after the third episode of malaria, which was confirmed by a positive blood smear for malarial parasites. His general condition gradually improved after a 6-day course of artesunate therapy. However, visual acuity in both eyes remained unchanged after artesunate therapy alone, with gradual improvement subsequently shown after pulse steroid therapy. Our case indicates that early antimalarial drugs combined with pulse steroid therapy may be of great importance for good visual recovery in ON cases after malarial infection.

Myelin oligodendrocyte glycoprotein antibody-associated optic neuritis: an update / Neurite óptica associada com anticorpo contra a glicoproteína oligondendrócita da mielina: uma breve atualização

ABSTRACT Myelin oligodendrocyte glycoprotein-immunoglobulin G (IgG)-associated optic neuritis has been established as a new entity of immune-mediated optic neuropathy. Patients usually present with recurrent optic neuritis, often bilaterally with initially severe vision loss and optic disc edema. However, in contrast to aquaporin 4-IgG-seropositive neuromyelitis optica spectrum disorder, visual recovery tends to be more favorable, with good response to steroid treatment. Another important differential diagnosis of myelin oligodendrocyte glycoprotein-IgG--associated optic neuritis is multiple sclerosis. Close monitoring for signs of relapse and long-term immunosuppression may be considered to maintain optimal visual function. The diagnosis can be made on the basis of the presence of a specific, usually serological, antibody against myelin oligodendrocyte glycoprotein (IgG; cell-based assay), and a demyelinating event (optic neuritis, myelitis, brainstem syndrome, or cortical lesions with seizures). The clinical spectrum of this newly recognized inflammatory demyelinating disease is expanding rapidly. We briefly review the epidemiological characteristics, clinical manifestations, diagnostic considerations, and treatment options of myelin oligodendrocyte glycoprotein-IgG-associated optic neuritis.

RESUMO A neurite óptica associada à glicoproteína de oligodendrócito de mielina-IgG foi estabelecida como uma nova entidade de neuropatia óptica imunomediada. Tipicamente os pacientes apresentam neurite óptica recorrente, muitas vezes bilateral, com perda de visão frequentemente severa e alta prevalência de edema do disco óptico na fase aguda. No entanto, em contraste com neuromyelitis optica spectrum disorder associada com presença de anticorpo contra aquaporina 4, a recuperação visual tende a ser mais favorável e responde bem ao tratamento com corticoide em altas doses. A esclerose múltipla representa outro importante diagnóstico diferencial de glicoproteína de oligodendrócito de mielina-IgG. O diagnóstico pode ser feito com base na presença de um anticorpo específico, geralmente sorológico contra glicoproteína de oligodendrócito de mielina (IgG, ensaio baseado em células), e presença de evento desmielinizante (neurite óptica, mielite, síndrome do tronco cerebral, lesões corticais com convulsões). O espectro clínico desta doença desmielinizante inflamatória recém-reconhecida está se expandindo rapidamente. Faremos uma breve revisão das características epidemiológicas, manifestações clínicas, considerações diagnósticas e opções de tratamento da neurite óptica associada à glicoproteína de oligodendrócito de mielina-IgG.