Multiple sclerosis. Part I: neuro-ophthalmic manifestations

Macular volume and fovea thickness as OCT-criteria for multiple sclerosis. Preliminary results

Background. The characteristic optical coherence tomography (OCT) changes in the optic nerve head in patients with multiple sclerosis are known and have been described many times, however, the state of the macular area is described in a small number of publications.The aim: to analyze the changes in the macular area of the retina in patients with multiple sclerosis, to identify the OCT signs pathognomonic for this disease and to trace their changes over time as the disease progresses.Material and methods. In addition to the standard ophthalmological examination, 28 patients (55 eyes) diagnosed with multiple sclerosis underwent OCT of the macular zone to determine the thickness of the fovea and the volume of the macula in the 6 mm zone. The follow-up period was 6–12 years. The endpoints were the primary treatment and the most recent inspection.Results. At the initial examination, the visual acuity was 0.96 ± 0.24 (95% CI: 0.9–1.03), fovea thickness – 253.0 μm (Q1–Q3: 233.0–264.0), macular volume – 5.471 mm3 (Q1–Q3: 5.281–5.625). In 37 cases (67.3 %), the macular volume was below normal. The initial fovea thickness was below normal in 9 cases (16.4 %). At the end of the study, visual acuity did not change statistically (p = 0.824) and amounted to 0.96 ± 0.25 (95% CI: 0.90–1.04). The fi nal thickness of the fovea was 247.5 μm (Q1–Q3: 233.0–260.0), changes are statistically significant (p = 0.02). Number of cases with a thickness below normal in the fi nal study was 11 (20 %), change of frequency of cases was not statistically signifi cant (p = 0.5). The fi nal macular volume was 5.393 mm3 (Q1–Q3: 5.197–5.565), the changes are statistically significant (p = 0.023). The final number of cases with a volume below the norm was 42 (76.4 %), the change in the frequency of cases is close to statistically signifi cant (p = 0.063). At all stages of the study, there was no case of an isolated decrease in the thickness of the fovea without a decrease in the volume of the macula.Conclusion. The decrease in the volume of the macula with time while maintaining the thickness of the fovea within the normal range can be attributed to the pathognomonic OCT signs of multiple sclerosis. This criterion can be used for a comprehensive assessment of the course and therapy of this disease.

Ocular adverse events from pharmacological treatment in patients with multiple sclerosis-A systematic review of the literature

PURPOSE

The aim of this study was to review the scientific evidence and describe the ocular treatment-emergent adverse events (TEAEs) related to pharmacological treatment in patients with multiple sclerosis.

METHODS

A systematic review of literature was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis guidelines in the MEDLINE, LILACS, EMBASE, and COCHRANE databases. Articles were filtered based on title and abstract considering the selection criteria and subsequently filtered by full-text reading. The resulting articles were evaluated using the Joanna Briggs Institute Quality Tools. Study characteristics and results were extracted and presented in structured tables to conduct a narrative synthesis.

RESULTS

A total of 2852 published articles were extracted using our strategy. After removing duplicates, 2841 articles were screened based on title and abstract, 102 articles were evaluated using quality tools, and 69 articles were filtered by full-text reading. Through this search strategy, 60 articles met all the inclusion criteria and seven articles, through a search update conducted in the same manner, were included. This resulted in 67 articles meeting the inclusion criteria, of which 11 were experimental and 56 were observational. The therapies related to ocular TEAEs were alemtuzumab, amantadine, fingolimod, steroids, CTLA-4 Ig, estriol, interferon β, natalizumab, hyperbaric oxygen, rituximab, siponimod, teriflunomide, and tovaxin. Fingolimod and siponimod were commonly associated with macular edema, interferon β was associated with retinopathy, alemtuzumab was associated with thyroid eye disease, amantadine was associated with corneal edema, and steroids were associated with acute retinal necrosis. Opportunistic infections were also found, and there was one life-threatening case.

CONCLUSIONS

Our search revealed different methodological assessments of the topic. However, longitudinal studies regarding ocular TEAEs related to multiple sclerosis therapy are necessary to provide evidence-based recommendations, especially in understudied regions such as Latin America and Africa. Physicians should monitor ocular symptoms in patients being treated for multiple sclerosis and consider an interdisciplinary approach.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO ID CRD42020106886.

Alleviation of extensive visual pathway dysfunction by a remyelinating drug in a chronic mouse model of multiple sclerosis

Visual deficits are among the most prevalent symptoms in patients with multiple sclerosis (MS). To understand deficits in the visual pathway during MS and potential treatment effects, we used experimental autoimmune encephalomyelitis (EAE), the most commonly used animal model of MS. The afferent visual pathway was assessed in vivo using optical coherence tomography (OCT), electroretinography (ERG), and visually evoked cortical potentials (VEPs). Inflammation, demyelination, and neurodegeneration were examined by immunohistochemistry ex vivo. In addition, an immunomodulatory, remyelinating agent, the estrogen receptor β ligand chloroindazole (IndCl), was tested for its therapeutic potential in the visual pathway. EAE produced functional deficits in visual system electrophysiology, including suppression of ERG and VEP waveform amplitudes and increased signal latencies. Therapeutic IndCl rescued overall visual system latency by VEP but had little impact on amplitude or ERG findings relative to vehicle. Faster VEP conduction in IndCl-treated mice was associated with enhanced myelin basic protein signal in all visual system structures examined. IndCl preserved retinal ganglion cells (RGCs) and oligodendrocyte density in the prechiasmatic white matter, but similar retinal nerve fiber layer thinning by OCT was noted in vehicle and IndCl-treated mice. Although IndCl differentially attenuated leukocyte and astrocyte staining signal throughout the structures analyzed, axolemmal varicosities were observed in all visual fiber tracts of mice with EAE irrespective of treatment, suggesting impaired axonal energy homeostasis. These data support incomplete functional recovery of VEP amplitude with IndCl, as fiber tracts displayed persistent axon pathology despite remyelination-induced decreases in latencies, evidenced by reduced optic nerve g-ratio in IndCl-treated mice. Although additional studies are required, these findings demonstrate the dynamics of visual pathway dysfunction and disability during EAE, along with the importance of early treatment to mitigate EAE-induced axon damage.

Anisocoria as initial manifestation of multiple sclerosis. Use of 3 tesla magnetic resonance imaging

A 21-year-old woman seen in this clinic with non-reactive mydriasis in the right eye that contracted with 1% pilocarpine. Cranial angio-CT and 1.5 T magnetic resonance imaging (MRI) did not detect any disease. Given a subsequent limitation of adduction, supraduction, and infarction of the right eye, a 3 T MRI was requested. This showed a lesion of the midbrain at the exit of the 3rd cranial nerve. After improvement, no new episodes were observed until 18 months later, when the patient presented with probable optic neuritis and systemic symptoms. At this time the 1.5 T MRI detected infratentorial and supratentorial demyelinating plaques. A subsequent lumbar puncture and clinic outcome confirmed the diagnosis of relapsing-remitting multiple sclerosis.

Clinical features of visual disturbances secondary to isolated sphenoid sinus inflammatory diseases

Background

Visual disturbances associated with isolated sphenoid sinus inflammatory diseases (ISSIDs) are easily misdiagnosed due to the nonspecific symptoms and undetectable anatomical location. The main objective of this retrospective case series is to investigate the clinical features of visual disturbances secondary to ISSIDs.

Methods

Clinical data of 23 patients with unilateral or bilateral visual disturbances secondary to ISSIDs from 2004 to 2014 with new symptoms were collected. Collected data including symptoms, signs, neuroimaging and pathologic diagnosis were analyzed.

Results

There were 14 males and 9 females, and their ages ranged from 31 to 83 years. Fifteen patients suffered blurred vision and 11 patients suffered binocular double vision, including 3 patients who had unilateral visual changes and diplopia simultaneously. Headache was observed in 18 patients, and orbit pain/ocular pain in 8 patients. Other presenting symptoms included ptosis (4 patients) and proptosis (1 patient). Only 5 patients had nasal complaints. The corrected visual acuities were between NLP to 20/20. Patients with diplopia included 5 with unilateral oculomotor nerve palsy and 6 with unilateral abducens nerve palsy. All patients performed orbital/sinus/brain radiologic examination and found responsible lesions in sphenoid sinus. All patients underwent endoscopic sinus surgery, and 9 patients were found to suffer sphenoid mucocele, 9 with fungal sinusitis, and 5 with sphenoid sinusitis. Visual disturbances improved in 6 patients, and all the patients with diplopia had a postoperative recovery.

Conclusion

Visual disturbances resulting from ISSIDs are relatively uncommon, but it is crucial that the patient with new vision loss or diplopia and persistent headache or orbit pain be evaluated for the possibility of ISSIDs especially before corticosteroid administration.

Accelerometer measured physical activity and the integrity of the anterior visual pathway in multiple sclerosis

PURPOSE

To examine the associations among objectively-measured physical activity with the optical coherence tomography (OCT) metrics of retinal nerve fiber layer (RNFL) thickness and total macular volume (TMV) in persons with multiple sclerosis (MS).

METHODS

Eighty four participants with MS, without ocular disease or high myopia underwent a neurological examination for Expanded Disability Status Scale (EDSS) scoring, followed by OCT. Participants then wore an accelerometer during the waking hours of a 7-day period to objectively measure physical activity as steps/day.

RESULTS

Mean RNFL thickness for the sample was 91.46μm (SD=15.0), and mean TMV was 6.61mm(3) (SD=0.5). The mean score from the accelerometer was 4287 steps/day (SD=2563). Steps/day was significantly associated with both RNFL thickness (Wald χ(2)=46.48, p<0.001) and TMV (Wald χ(2)=1798.27, p<0.001). After controlling for sex, MS subtype, disease duration, disability, and visual function, steps/day was significantly associated with TMV (Wald χ(2)=58.93, p<0.001), but not RNFL (Wald χ(2)=0.001, p=0.973).

CONCLUSIONS

Physical activity was associated with integrity of the anterior visual pathway, assessed by OCT, in persons with MS, and this association was independent of sex, MS subtype, disease duration, disability, and visual function. Researchers should consider examining the causal nature of the association between physical activity and markers of the visual system in MS.

Decreased Ocular Pulse Amplitude and Retinal Nerve Fibre Layer in Multiple Sclerosis

This study was conducted to assess ocular pulse amplitude and retinal nerve fibre layer in patients with multiple sclerosis and their correlation with disease duration and with severity. Retinal nerve fibre layer thickness was measured by Heidelberg Retinal Tomography II (HRT-II; Heidelberg Engineering, Dossenheim, Germany) and ocular pulse amplitude was measured by dynamic contour tonometry (Ziemer Ophthalmic Systems, Port, Switzerland) in 37 multiple sclerosis patients and 72 age- and gender-matched controls. Ocular pulse amplitude was significantly reduced and retinal nerve fibre layer was significantly thinner in temporal, superotemporal, and nasal sectors in patients with multiple sclerosis regardless of having an optic neuritis attack. The retinal nerve fibre layer was thinner in eyes with a previous optic neuritis attack compared with the eyes without an attack, but the difference was not significant. Ocular pulse amplitude showed a positive correlation with visual evoked potential amplitude and a negative correlation with visual evoked potential latency. Retinal nerve fibre layer thickness showed a significant negative correlation with the disease duration but not with visually evoked potential, disease severity, nor previous optic neuritis. These findings indicate that the process of degeneration starts in the early period of the disease, as our study group is composed of early-middle-stage multiple sclerosis patients, and is independent of relapses.

Current options for the treatment of optic neuritis

Optic neuritis can be defined as typical (associated with multiple sclerosis, improving independent of steroid treatment), or atypical (not associated with multiple sclerosis, steroid-dependent improvement). Causes of atypical optic neuritis include connective tissue diseases (eg, lupus), vasculitis, sarcoidosis, or neuromyelitis optica. In this manuscript, updated treatment options for both typical and atypical optic neuritis are reviewed. Conventional treatments, such as corticosteroids, therapeutic plasma exchange, and intravenous immunoglobulin therapy are all discussed with commentary regarding evidence-based outcomes. Less commonly used treatments and novel purported therapies for optic neuritis are also reviewed. Special scenarios in the treatment of optic neuritis – pediatric optic neuritis, acute demyelinating encephalomyelitis, and optic neuritis occurring during pregnancy – are specifically examined.

[Optical coherence tomography in neuro-ophthalmology]

INTRODUCTION

Optical coherence tomography (OCT) is a potential tool for diagnosis and follow-up in diseases of the anterior visual pathway in that it provides a reproducible and reliable quantification of retinal nerve fiber layer (RNFL) thickness. A review of the literature was conducted to define the utility of OCT in neuro-ophthalmology.

MATERIALS AND METHODS

The clinical applications of RNFL thickness measurement by OCT time domain were analyzed. The PubMed search engine enabled us to select the relevant publications, using the following keywords: "optic neuropathy", "retinal nerve fiber layer thickness", and "optical coherence tomography". Publications concerning glaucoma were excluded from this review.

RESULTS

The course of RNFL thickness depends on the underlying disease: (I) progressive reduction toward atrophy (e.g., optic neuritis, chiasmal compression) or (II) initial increase in RNFL thickness followed by a reduction toward (IIa) normalization (papilledema) or (IIb) atrophy (anterior ischemic optic neuropathy, Leber hereditary optic neuropathy).

DISCUSSION

Depending on the type of anterior visual pathway impairment, OCT provides RNFL data relevant for diagnosis, follow-up, and prognosis. As in macular disease, OCT has become an important clinical tool for routine disease assessment in neuro-ophthalmology.

Sight-dependent quality of life and ophthalmic findings in a group of Brazilian patients with multiple sclerosis

OBJECTIVE

To assess the visual quality of life in patients with multiple sclerosis (MS), and to observe whether this parameter could be correlated to the findings of the ophthalmologic examination.

METHOD

The translated and validated 25-Item National Eye Institute Visual Function Questionnaire (VFQ-25) was used to assess the visual quality of life. Clinical data on MS, visual acuity, visual fields, optic coherence tomography (OCT) and disc cupping were used for assessing correlation with VFQ-25.

RESULTS

The mean VFQ-25 value was 78.6 ± 18.2% in 27 patients. VFQ-25 did not correlate with patients' ages, with disability (EDSS), disease duration or medication use. Visual acuity showed a relatively poor (<60%) correlation to VFQ-25, while no correlation could be established between visual fields, OCT and disc cupping with VFQ-25.

CONCLUSION

MS patients present several alterations in their eyes and sight that cannot be assessed by isolated measures. Ophthalmological examination of these patients must include many parameters not usually used in standard ophthalmologic consultations.

Optical coherence tomography in multiple sclerosis and neuromyelitis optica: an update

Optical coherence tomography (OCT) uses light interference patterns to produce a cross-sectional image of the retina. It is capable of measuring the unmyelinated axons of the retinal ganglionar cells as they converge on the optic disc. In a disease like multiple sclerosis (MS), in which axonal loss has been identified as an important cause of sustained disability, it may prove an invaluable tool. OCT has demonstrated that axonal loss occurs after each episode of optic neuritis and that the degree of axonal loss is correlated to visual outcomes. Furthermore, axonal loss occurs in MS even in the absence of inflammatory episodes, and the degree of this loss is correlated with the duration of the disease process, with more thinning as the disease advances and in progressive forms. Thus, OCT retinal nerve fiber layer measurements may represent an objective outcome measure with which to evaluate the effect of treatment.

Charles Bonnet syndrome

BACKGROUND

Charles Bonnet syndrome (CBS) involves nonthreatening hallucinations in patients who have no neurological and no psychological abnormalities but with significant visual impairment secondary to ocular disease, such as macular degeneration and diabetic retinopathy. Because of the fear of a mental illness being diagnosed, patients are often reluctant to discuss these hallucinations.

CASE REPORTS

Three cases are presented of patients who experienced CBS caused by decreased vision. Each patient had decreased vision and related visual hallucinations that were consistent with CBS. The first patient underwent magnetic resonance imaging and psychological evaluation, which confirmed our suspicion. The other 2 patents were not willing to undergo further testing, so our diagnosis is presumptive.

CONCLUSION

Management for these hallucinations includes treatment of the actual ocular disease as well as optimizing vision for the patient using appropriate low vision devices. As the population continues to age, more patients will be seen with reduced vision caused by a myriad of ocular diseases, increasing the likelihood that more patients may present with CBS in the future. It is therefore prudent to become familiar with the syndrome so primary care optometrists can properly identify CBS and help their patients deal with it.

Evaluation of a transgenic mouse model of multiple sclerosis with noninvasive methods

PURPOSE

To evaluate the ND4 transgenic mouse model of multiple sclerosis using noninvasive methods.

METHODS

Assessment of neurologic/behavioral abnormalities was made using pattern electroretinogram (PERG), magnetic resonance imaging (MRI), optic coherence tomography (OCT), and end point histologic analysis.

RESULTS

Electrophysiologic (PERG) recordings demonstrated functional deficits in vision commensurate with neurologic/behavioral abnormalities. In ND4 mice, the authors found PERG abnormalities preceded neurologic/gait abnormalities. MRI demonstrated subtle structural changes that progressed over time in correlation with behavioral abnormalities.

CONCLUSIONS

The ND4 mouse model has been evaluated using well-defined parameters of noninvasive methods (PERG, MRI, and OCT), enabling objective identification of functional and structural deficits and their correlation with neurologic/gait abnormality.