Association of peripapillary hyper-reflective ovoid masslike structures and disease duration in primary progressive multiple sclerosis

Peripapillary hyperreflective ovoid mass-like structures: multimodal imaging and associated diseases

Growing evidence has demonstrated that peripapillary hyperreflective ovoid mass-like structures (PHOMS) are novel structures rather than a subtype of optic disc drusen. They correspond to the laterally bulging herniation of optic nerve fibers and are believed to be the marker of axoplasmic stasis. PHOMS present in a broad spectrum of diseases, including optic disc drusen, tilted disc syndrome, papilloedema, multiple sclerosis, non-arteritic anterior ischemic optic neuropathy, optic neuritis, Leber hereditary optic neuropathy, and so on. We focus on the multimodal imaging features, pathophysiological mechanisms of PHOMS, and their association with multiple diseases and healthy people in this review to deepen the ophthalmologists' understanding of PHOMS. Additionally, we provide some new directions for future research.

[Retinal OCT biomarkers and neurodegenerative diseases of the central nervous system beyond Alzheimer's disease]

BACKGROUND

Optical coherence tomography (OCT) biomarkers are increasingly used by neurologists, psychiatrists, and ophthalmologists for the diagnosis, prognosis, and follow-up of neurodegenerative diseases. Long-term data on OCT biomarkers of selected primary and secondary neurodegenerative diseases of the central nervous system (CNS), such as multiple sclerosis (MS) or Parkinson's disease, are already available in part. In addition, there are rare neurodegenerative diseases with early disease onset that may show OCT abnormalities.

METHODS

A literature review on the association of OCT biomarkers with neurodegenerative diseases of the CNS beyond Alzheimer's disease is presented. Parkinson's disease, MS, Friedreich's ataxia, Huntington's disease, spinocerebellar ataxia, and lysosomal storage diseases are addressed.

RESULTS

Relevant OCT biomarkers of neurodegenerative diseases are the macular ganglion cell inner plexiform layer (GCIPL) and the peripapillary retinal nerve fiber layer (pRNFL) thickness. Different sectors may be affected depending on the disease entity in addition to global pRFNL reduction. OCT‑angiography (OCT-A) is also increasingly used as a biomarker in neurodegenerative diseases.

CONCLUSION

Optical coherence tomography biomarkers are used in an interdisciplinary context. Retinal pathologies should be excluded by an ophthalmologist. While OCT biomarkers are increasingly used clinically in MS, the benefit in other neurodegenerative diseases, especially the rare ones, is less well documented. Further longitudinal studies are required.

Current knowledge on multiple sclerosis pathophysiology, disability progression assessment and treatment options, and the role of autologous hematopoietic stem cell transplantation

Multiple sclerosis (MS) is an autoimmune disease of the central nervous system (CNS) that affects nearly 2.8 million people each year. MS distinguishes three main types: relapsing-remitting MS (RRMS), secondary progressive MS (SPMS) and primary progressive MS (PPMS). RRMS is the most common type, with the majority of patients eventually progressing to SPMS, in which neurological development is constant, whereas PPMS is characterized by a progressive course from disease onset. New or additional insights into the role of effector and regulatory cells of the immune and CNS systems, Epstein-Barr virus (EBV) infection, and the microbiome in the pathophysiology of MS have emerged, which may lead to the development of more targeted therapies that can halt or reverse neurodegeneration. Depending on the type and severity of the disease, various disease-modifying therapies (DMTs) are currently used for RRMS/SPMS and PPMS. As a last resort, and especially in highly active RRMS that does not respond to DMTs, autologous hematopoietic stem cell transplantation (AHSCT) is performed and has shown good results in reducing neuroinflammation. Nevertheless, the question of its potential role in preventing disability progression remains open. The aim of this review is to provide a comprehensive update on MS pathophysiology, assessment of MS disability progression and current treatments, and to examine the potential role of AHSCT in preventing disability progression.

Peripapillary hyper-reflective ovoid mass-like structures (PHOMS): clinical significance, associations, and prognostic implications in ophthalmic conditions

Pioneering advancements in optical coherence tomography (OCT) have facilitated the discernment of peripapillary hyper-reflective ovoid mass-like structures (PHOMS), prevalent neuro-ophthalmological findings associated with an array of ophthalmic conditions, such as optic disc drusen (ODD), papilledema, myopic/tilted optic discs, non-arteritic anterior ischemic optic neuropathy (NA-AION), and optic neuritis. Despite an expanding corpus of research, numerous inquiries persist concerning their clinical significance, correlations with ocular afflictions, and prognostic implications. This comprehensive review endeavors to impart an in-depth comprehension of PHOMS, encompassing facets like conceptualization, detection, pathogenesis, and associations with diverse ophthalmic conditions. Furthermore, we underscore several unresolved quandaries and suggest prospective avenues for future exploration.

Peripapillary hyper-reflective ovoid mass-like structures (PHOMS) in AQP4-IgG-positive neuromyelitis optica spectrum disease (NMOSD) and MOG-IgG-associated disease (MOGAD)

BACKGROUND

Peripapillary hyperreflective ovoid mass-like structures (PHOMS) have recently been described as new optical coherence tomography (OCT) marker. It is not yet clear whether the occurrence of PHOMS is disease-specific or disease-spanning. PHOMS have been described in 16-18% of patients with multiple sclerosis (MS). Currently, no data on the prevalence of PHOMS in other demyelinating diseases including aquaporine-4-IgG-positive neuromyelitis optica spectrum disease (AQP4 + NMOSD) or myelin oligodendrocyte glycoprotein-IgG-associated disease (MOGAD) are reported.

METHODS

We performed a cross-sectional, retrospective spectral domain OCT study evaluating the frequency of PHOMS in AQP4 + NMOSD (n = 47) and MOGAD (n = 44) patients. To test the association with retinal neuroaxonal damage, we compared demographic and clinical data as well as retinal layer thicknesses between eyes with vs. eyes without PHOMS.

RESULTS

PHOMS were detected in 17% of AQP4 + NMOSD and 14% of MOGAD patients. Intra-cohort analysis revealed that AQP4 + NMOSD patients with PHOMS were significantly older [mean (years): 57.5 vs. 50.0; p value = 0.04]. We found no association of PHOMS with retinal neuroaxonal degeneration. In addition, in subjects with only one eye affected by PHOMS compared with the unaffected fellow eye, no differences in retinal parameters were observed (n = 4).

CONCLUSIONS

In summary, we found PHOMS in 17% of AQP4 + NMOSD and 14% of MOGAD patients. This is comparable to the prevalence of published MS PHOMS data. Therefore, a disease-specific occurrence of PHOMS is unlikely. Interestingly, PHOMS do not seem to depend on retinal neuroaxonal degeneration.

Peripapillary hyperreflective ovoid mass-like structures: Multimodal imaging-A review

Peripapillary hyperreflective ovoid mass-like structures (PHOMS) are a laterally bulging herniation of distended axons into the peripapillary region above the level of Bruch's membrane opening. Increased use of enhanced depth imaging-optical coherence tomography (EDI-OCT) in our evaluation of the optic nerve head (ONH) and greater recognition of the vast range of optic nerve pathologies with which PHOMS is associated provides convincing evidence that PHOMS is not just buried optic disc drusen (ODD) as previously described. The frequent coexistence of PHOMS with ODD, papilloedema, anterior ischaemic optic neuropathy, tilted optic disc syndrome, inflammatory demyelinating disorders and other diseases associated with axoplasmic stasis provides insight into its underlying pathophysiology. The present review will discuss the role of key imaging modalities in the differential diagnosis of PHOMS, explore the current literature on the relationship between PHOMS and common neuro-ophthalmic conditions, and highlight the gaps in our knowledge, with respect to disease classification and prognosis, to pave the way for future directions of research.

An overview of peripapillary hyperreflective ovoid mass-like structures

PURPOSE OF REVIEW

The purpose of this review is to provide an overview of the ophthalmic findings associated with peripapillary hyperreflective ovoid mass-like structures (PHOMS) in both adult and pediatric patients.

RECENT FINDINGS

PHOMS have recently been identified in a number of different ophthalmic disease entities ranging from nonpathologic to pathologic, including but not limited to anatomic abnormalities (tilting in myopia), optic nerve head drusen, optic disc edema from inflammation (optic neuritis, white dot syndromes), vascular insults (ischemic optic neuropathy, retinal vascular occlusion), and papilledema. The mechanism underlying the formation of PHOMS has not been fully elucidated although it has been hypothesized that PHOMS occur secondary to axoplasmic stasis from crowding at the optic nerve head.

SUMMARY

Although the clinical significance of the presence of PHOMS remains unclear, PHOMS are associated with several disease processes. Understanding the mechanism behind their formation and their impact on optic nerve head structure and visual function may be relevant in patients with optic nerve head pathology. The presence of PHOMS may also correlate with disease severity and duration. Future studies to evaluate whether the formation of PHOMS may be useful as an early indicator of disease or a prognostic tool are warranted.

Optical Coherence Tomography and Optical Coherence Tomography with Angiography in Multiple Sclerosis

Multiple sclerosis (MS) is an inflammatory and neurodegenerative, potentially disabling disease of the central nervous system. OCT (Optical Coherence Tomography) and OCT-A (Optical Coherence Tomography with Angiography) are imaging techniques for the retina and choroid that are used in the diagnosis and monitoring of ophthalmological conditions. Their use has recently expanded the study of several autoimmune disorders, including MS. Although their application in MS remains unclear, the results seem promising. This review aimed to provide insight into the most recent OCT and OCT-A findings in MS and may function as a reference point for future research. According to the current literature, the retinal nerve fibre layer (RNFL) and ganglion cell-inner plexiform complex (GC-IPL) are significantly reduced in people with MS and are inversely correlated with disease duration. The use of OCT might help distinguish between MS and neuromyelitis optica spectrum disorders (NMOSD), as the latter presents with more pronounced thinning in both the RNFL and GC-IPL. The OCT-A findings in MS include reduced vessel density in the macula, peripapillary area, or both, and the enlargement of the foveal avascular zone (FAZ) in the setting of optic neuritis. Additionally, OCT-A might be able to detect damage in the very early stages of the disease as well as disease progression in severe cases.

Retinal imaging with optical coherence tomography in multiple sclerosis: novel aspects

Optical coherence tomography (OCT) is of increasing interest in the clinical assessment of multiple sclerosis (MS) patients beyond the scope of clinical studies. In this narrative review, we discuss novel changes of OCT parameters during acute optic neuritis and the disease course of MS patients. OCT images document the changes of retinal layers during an episode of acute optic neuritis and can therefore provide valuable insights into the pathophysiology. Moreover, MS patients show progredient thinning of retinal layers throughout the disease. The thinning is accelerated through relapses as well as disease progression without relapse. The OCT parameters are also associated with clinical outcome parameters, including disability, cognitive function, and brain atrophy. The impact of disease-modifying therapies on OCT parameters is the subject of ongoing research and depends on the agent used. Additional data are still necessary before OCT parameters can be implemented in the clinical standard of care of MS patients.