Optic neuritis: A South African hospital-based prospective study protocol.

BACKGROUND: Optic neuritis is a relatively common disease with an estimated lifetime risk of 0.6 per 1000; the estimated prevalence is 1-5 per 100 000/year. It occurs because of inflammation of the optic nerve from a variety of causes. The diagnosis of the disorder is established clinically and current literature is predominantly based on white patients from high-income countries. Optic neuritis presents differently in black patients compared to white patients. This study aims to assess the presentation and outcome of optic neuritis patients in a South African setting. METHODS: This is a prospective, hospital-based cohort study that will enrol patients with optic neuritis presenting to either the neurology department at Chris Hani Baragwanath Academic Hospital or the ophthalmology department at St John Eye Hospital, both in Johannesburg, South Africa. The specific aetiologies, clinical presentation and radiological findings will be studied, and the patient's course over one year will be documented in three-monthly follow-up visits. A specific group of patients with Neuromyelitis Optica Spectrum Disorders (NMOSD) and Myelin Oligodendrocyte Glycoprotein Associated Disorders (MOGAD) optic neuritis will be followed up for 5 years at yearly intervals. DISCUSSION: This study represents one of the few cohort studies in Sub-Saharan Africa that seeks to investigate optic neuritis. Our hope is that it will lead to better insights regarding the presentation, course and outcome of this condition. We will also analyse the data with a view of developing a predictive model for good visual outcome.

Ischemic ocular manifestations of giant cell arteritis: A Canadian case series.

BACKGROUND: Diagnosing giant cell arteritis (GCA) can be challenging due to the variable clinical presentation and lack of systemic symptoms in approximately 20% of cases, which are termed occult GCA. GCA affects the ocular circulation in more than half of cases and can cause irreversible bilateral blindness if not rapidly recognized and treated. We compared clinical and laboratory findings of patients with occult and systemic temporal artery biopsy (TAB)-positive GCA with ocular manifestations. METHODS: Retrospective chart review of patients with TAB-positive GCA with ocular manifestations seen at a tertiary neuro-ophthalmology practice between 2015 and 2020. RESULTS: GCA was occult in 14.3% (6/42) and systemic in 85.7% (36/42) of patients. Occult GCA affected older patients (average age 84.6 ± 5.3 vs 75.9 ± 8.2). There was no significant difference in ESR or CRP levels between two cohorts. In patients with occult GCA, 83.3% (5/6) presented with AION, and 16.7% (1/6) with isolated cranial nerve six palsy (CN6P). In the systemic GCA cohort, 47.2% (17) presented with AION, 5.6% (2) with CRAO, 2.8% (1) with PION, 2.8% (1) with isolated CWS, 2.8% (1) had both CRAO and AION, 2.8% (1) isolated cranial nerve 4 palsy (CN4P), 2.8% (1) isolated CN6P, 22.2% (8) had history of amaurosis fugax but normal examination, and 11.1% (4) had visual symptoms but a normal exam. Three of the above patients with AION also had CN4P. Of patients diagnosed with AION, presenting visual acuity in the affected eye(s) was significantly worse in patients with occult GCA. Involvement of multiple ocular circulations was seen in six patients in the systemic group but none in the occult group. CONCLUSION: Occult GCA occurs more commonly in older patients who most of the time present with AION. Levels of inflammatory markers were similar in the occult and systemic groups. Though ocular ischemic manifestations were similar in both cohorts, in systemic GCA involvement of multiple ocular circulations is likely more common GCA should always be considered in older patients who present with signs of retinal and/or optic nerve head ischemia (AION and/or CWS) and new onset of CNPs, especially in patients where more than one ocular arterial circulation is involved.

Binasal Visual Field Defects Due to Sickle Cell Maculopathy.

ABSTRACT: A 26-year-old African American man with sickle cell disease noticed blurry vision in both eyes after a recent complicated hospital admission for sickle cell crisis. Anterior and posterior segment examination of each eye was normal, but visual field testing revealed binasal scotomas. Optical coherence tomography of the macula demonstrated severe thinning of the temporal inner retina, suggesting previous bilateral occlusions of terminal retinal arterioles involving the temporal macula, an uncommon complication of sickle cell disease. This case is a reminder that retinal pathology should always be considered as a potential cause of unexplained visual field defects and highlights the role of macular OCT in evaluation of these patients.

Optic Disc Edema in Syphilis.

BACKGROUND: Syphilis is an uncommon cause of optic nerve head edema; however, differentiating syphilis from other etiologies of optic nerve head swelling may be challenging. We describe 4 cases of ocular syphilis presenting with swollen optic nerve head(s) without overt signs of intraocular inflammation to better define the phenotypic presentation of this condition to allow its early recognition and treatment and discuss potential pathophysiological mechanisms of syphilitic optic neuropathy. METHODS: Retrospective case series of patients presenting to a tertiary neuro-ophthalmology practice with a swollen optic nerve head(s) but no overt signs of intraocular inflammation, which was eventually determined to be secondary to syphilis. RESULTS: Four patients were included in the study. The mean age was 43 years, 2 were women and 2 had bilateral involvement. Two patients had a recent history of skin rash, and one patient was investigated for abdominal pain and elevated liver enzymes. Two patients presented with photopsias and preserved visual function, whereas 2 presented with vision loss. Although chorioretinitis was present in all cases, it was very subtle in all and was only appreciated on fundus autofluorescence (FA) in 3 of 4 cases. Three patients demonstrated evidence of optic perineuritis on neuro-imaging. All patients were treated with a course of intravenous penicillin with a variable degree of visual recovery. CONCLUSIONS: Systemic symptoms are common in patients with syphilic optic neuropathy. Optic disc edema as a manifestation of syphilis is usually accompanied by subtle chorioretinitis, which is best appreciated on FA. Optic perineuritis is common in patients with syphilitic optic neuropathy, with its pathophysiology likely similar to meningitis seen in neurosyphilis.

Older woman with abdominal pain and bilateral sequential vision loss due to syphilis.

A 62-year-old woman presented with non-specific abdominal pain, elevated alkaline phosphatase levels and bilateral sequential visual loss. Visual acuity was counting fingers in right eye (RE) and 20/400 in left eye (LE). She was noted to have optic nerve pallor in RE and mildly elevated optic disc with signs of ocular inflammation in LE. After 2 weeks, vision deteriorated to light perception bilaterally with now extensive vitreal inflammation present in both eyes. Positive rapid plasma reagen and Treponema pallidum's antibody tites confirmed syphilis infection. Unfortunately, as the diagnosis was delayed by many months, her visual acuity remained poor (hand motions in RE and 20/50 in LE) despite treatment with intravenous penicillin. This case reminds us of the re-emergence of this 'great masquerader' and highlights the importance of maintaining high suspicion for syphilis in patients with unexplained visual loss and systemic symptoms, even in older adults without identifiable risk factors.

Baló's concentric sclerosis - A rare entity within the spectrum of demyelinating diseases.

Baló's concentric sclerosis (BCS) is a rare, inflammatory demyelinating disease of the central nervous system (CNS). Historically, BCS was thought to be uniformly fatal and diagnosis was based on postmortem findings. With advances in modern neuroimaging, BCS is currently defined by the presence of concentric layered patterns composed of alternating rings of varying intensity. They are best appreciated on gadolinium-enhanced T1-weighted sequences and predominantly occur in the supratentorial cerebral white matter with sparing of cortical U-fibers. The lamellar pattern of the lesions likely reflects bands of demyelination and relative myelin preservation with minimal axonal loss. While BCS falls within the spectrum of atypical demyelinating diseases, there is ongoing debate over whether BCS is a phenotypical variant of multiple sclerosis (MS) or a separate entity. Corticosteroids comprise first-line therapy but there is ongoing controversy regarding appropriate maintenance therapy. First-line MS disease-modifying therapies such as interferon beta-1a are appropriate for patients who fulfill diagnostic criteria for relapsing-remitting MS. Fingolimod should likely be avoided as Baló-like lesions have been reported during its administration or after withdrawal. Monoclonal antibodies such as natalizumab and rituximab are potentially effective at reducing BCS relapses, but alemtuzumab may be relatively ineffective because humoral immunity does not play a central role in BCS pathogenesis.

Lipomatosis and optic neuropathy clinches the diagnosis of myoclonic epilepsy with ragged red fibres (MERRF) syndrome.

We present a rare case of myoclonic epilepsy with ragged red fibres with high level of heteroplasmy presenting with optic neuropathy and a rare phenotype of lipomatosis. Cutaneous lipomas are typically thought of as a benign/isolated entity and this case emphasises importance of considering mitochondrial disease in all patients with lipomatosis especially in the presence of other systemic abnormalities.

Bitemporal Hemianopia Secondary to Acute Zonal Occult Outer Retinopathy.

ABSTRACT: A 58-year-old man noticed shadows in the temporal visual field of each eye and photopsias within these scotomas for the past year. Formal visual fields demonstrated bitemporal hemianopia. MRI of the sella was normal, but fundus autofluorescence (FAF) demonstrated an area of hyperautofluorescence in the nasal retina of each eye corresponding to the loss of retinal pigment epithelium and photoreceptors. A diagnosis of acute zonal occult outer retinopathy was made based on the presence of trizonal involvement on FAF. This case is a reminder that bitemporal hemianopia can be caused by a retinopathy involving nasal retina in each eye, and FAF is a very useful test when assessing patients with suspected outer retinal disorders.

Recurrent Third Nerve Palsy Secondary to Instrinsic Schwannoma of the Third Cranial Nerve.

ABSTRACT: A 78 year-old woman has experienced multiple episodes of transient right third nerve palsy over the course of 15 years and has undergone multiple imaging studies as well as investigations for myasthenia gravis and giant cell arteritis in search for the diagnosis. When seen after the most recent episode, MRI with contrast and Fast-Imaging Employing Steady-State Acquisition protocol revealed a subtle enlargement and enhancement of the cisternal and proximal cavernous portions of the right third cranial nerve. An empiric diagnosis of schwannoma intrinsic to third cranial nerve was made. All patients with cyclical third nerve palsies should have appropriate neuroimaging to rule out subtle structural lesions before other investigations are undertaken.

Transient Monocular Visual Loss: When Is It an Emergency?

BACKGROUND: Patients who experienced transient monocular vision loss (TMVL) commonly present to the emergency department for evaluation. Although multiple etiologies can cause TMVL, it is most important to identify patients with retinal ischemia and those with vasculitis (giant cell arteritis) as the cause of TMVL. Patients with transient retinal ischemia have the same risk of cardiovascular events and death as patients who experienced transient brain ischemia. Patients with giant cell arteritis are at imminent risk of visual loss. CASE REPORT: A 65-year-old man noticed three separate episodes of sudden onset of blurry vision in one eye. Ophthalmologic examination was normal but, as his symptoms were compatible with transient retinal ischemic attack, urgent investigations were initiated. He had normal inflammatory markers but computed tomography angiogram of the brain and neck demonstrated a large plaque in the ipsilateral internal carotid artery. Double anti-platelet therapy was started and stenting of the involved carotid artery was performed. The patient was symptom-free at the last follow-up. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Patients with retinal ischemia as the etiology of TMVL are at high risk of cardiovascular events and death. Their risk of cerebrovascular accidents is highest within 48 h from the episode of TMVL, thus they should have an urgent ophthalmologic examination and, if it is unrevealing, inflammatory markers should be checked and an urgent stroke prevention protocol should be initiated. Appropriate management with medical or surgical interventions significantly reduces morbidity and mortality in these patients.

Neuroretinitis in a young woman.

•Neuroretinitis is unilateral optic nerve head edema followed 2-4 weeks later by development of macular star.•Typically, severe optic nerve head edema is out of keeping with relatively preserved visual function.•As the site of pathology are leaky capillaries on optic nerve head and not optic nerve axons, RAPD is mild or not present.•Most cases are either idiopathic or secondary to specific infectious etiologies.•Patients with neuroretinitis are not at risk of developing multiple sclerosis and do not require neuro-imaging in most cases.