Longitudinal stability of inter-eye differences in optical coherence tomography measures for identifying unilateral optic nerve lesions in multiple sclerosis

Test-retest reliability of Cirrus HD-optical coherence tomography retinal layer thickness measurements in people with multiple sclerosis

Background

Optical coherence tomography (OCT) allows evaluation of inter-eye differences (IEDs) in peri-papillary retinal nerve fiber layer (pRNFL) and macular ganglion cell-inner plexiform layer (GCIPL) thicknesses to identify unilateral optic nerve involvement (UONI), which is included in the 2024 revised McDonald diagnostic criteria for multiple sclerosis (MS).

Objectives

To evaluate the test-retest reliability of pRNFL and GCIPL thicknesses/IEDs in people with MS, other neurological disorders, and healthy controls using Cirrus HD-OCT.

Methods

509 participants underwent Cirrus HD-OCT, acquiring two macular and optic disc scans per eye within each session. Scans meeting OSCAR-IB quality control criteria were included in final analyses (959 eyes), with no clinical/demographic exclusions (reflecting a real-world clinical setting). Reliability was assessed using coefficients of variation (COVs), intraclass correlation coefficients (ICCs), and Bland-Altman limits of agreement (LOA). IED consistency was evaluated using difference-in-differences (DiDs) of test-retest measurements.

Results

GCIPL demonstrated superior reliability (ICC: 0.998, COV: 0.40%, LOA: -1.29 to 1.35 μm) to pRNFL (ICC: 0.989, COV: 1.18%, LOA: -3.59 to 3.70 μm) thickness. Inter-eye absolute DiDs [pRNFL: 2.00 μm (standard deviation (SD) 1.73); GCIPL: 0.64 μm (SD 0.67)] were lower than IED thresholds proposed for identifying UONI.

Conclusions

The excellent reliability of GCIPL and pRNFL thicknesses/IEDs support OCT for identifying UONI to diagnose MS.

Longitudinal analysis of retinal and choriocapillaris in patients with multiple sclerosis: a 3-year study

OBJECTIVES

This study investigated the longitudinal progression of retinal structure and microvasculature over 3 years in patients with relapsing-remitting multiple sclerosis (RRMS) using optical coherence tomography (OCT) and OCT angiography (OCTA). It also explored the correlation between these changes and the Expanded Disability Status Scale (EDSS) scores.

METHODS

In this prospective, longitudinal study, we enrolled 66 patients with RRMS without history of optic neuritis and 124 healthy controls. All participants underwent full ophthalmological examination, OCT/OCTA scans, and disability scoring (EDSS) at baseline and after 12 and 24 months. OCT data were analyzed for retinal layer thickness, while OCTA assessed microvascular perfusion in the retinal capillary plexuses and choriocapillaris. Statistical models evaluated yearly rates of change and their association with EDSS scores.

RESULTS

The patients with RRMS exhibited 3.6 times faster thinning of the inner plexiform layer (IPL; - 0.47 µm per year, P = 0.001) compared to controls over 3 years. Additionally, superficial retinal capillary layer perfusion density decreased more rapidly at - 0.44% per year (P = 0.006) in patients with MS. A strong correlation was found between worsening EDSS scores and accelerated ONL thinning (estimated coefficient: - 1.62 µm/per unit change of EDSS score, P = 0.004).

DISCUSSION

This study demonstrates progressive retinal neurodegeneration and microvascular dysfunction in patients with RRMS without a history of optic neuritis. The association between ONL thinning and increased disability supports the potential of OCT/OCTA as valuable tools for monitoring disease progression and severity in RRMS.

Imaging the eye as a window to brain health: frontier approaches and future directions

Recent years have seen significant advances in diagnostic testing of central nervous system (CNS) function and disease. However, there remain challenges in developing a comprehensive suite of non- or minimally invasive assays of neural health and disease progression. Due to the direct connection with the CNS, structural changes in the neural retina, retinal vasculature and morphological changes in retinal immune cells can occur in parallel with disease conditions in the brain. The retina can also, uniquely, be assessed directly and non-invasively. For these reasons, the retina may prove to be an important "window" for revealing and understanding brain disease. In this review, we discuss the gross anatomy of the eye, focusing on the sensory and non-sensory cells of the retina, especially microglia, that lend themselves to diagnosing brain disease by imaging the retina. We include a history of ocular imaging to describe the different imaging approaches undertaken in the past and outline current and emerging technologies including retinal autofluorescence imaging, Raman spectroscopy, and artificial intelligence image analysis. These new technologies show promising potential for retinal imaging to be used as a tool for the diagnosis of brain disorders such as Alzheimer's disease and others and the assessment of treatment success.

Diagnosis of multiple sclerosis using optical coherence tomography supported by explainable artificial intelligence

BACKGROUND/OBJECTIVES

Study of retinal structure based on optical coherence tomography (OCT) data can facilitate early diagnosis of relapsing-remitting multiple sclerosis (RRMS). Although artificial intelligence can provide highly reliable diagnoses, the results obtained must be explainable.

SUBJECTS/METHODS

The study included 79 recently diagnosed RRMS patients and 69 age matched healthy control subjects. Thickness (Avg) and inter-eye difference (Diff) features are obtained in 4 retinal layers using the posterior pole protocol. Each layer is divided into six analysis zones. The Support Vector Machine plus Recursive Feature Elimination with Leave-One-Out Cross Validation (SVM-RFE-LOOCV) approach is used to find the subset of features that reduces dimensionality and optimises the performance of the classifier.

RESULTS

SVM-RFE-LOOCV was used to identify OCT features with greatest capacity for early diagnosis, determining the area of the papillomacular bundle to be the most influential. A correlation was observed between loss of layer thickness and increase in functional disability. There was also greater functional deterioration in patients with greater asymmetry between left and right eyes. The classifier based on the top-ranked features obtained sensitivity = 0.86 and specificity = 0.90.

CONCLUSIONS

There was consistency between the features identified as relevant by the SVM-RFE-LOOCV approach and the retinotopic distribution of the retinal nerve fibres and the optic nerve head. This simple method contributes to implementation of an assisted diagnosis system and its accuracy exceeds that achieved with magnetic resonance imaging of the central nervous system, the current gold standard. This paper provides novel insights into RRMS affectation of the neuroretina.

Optic nerve topography in multiple sclerosis diagnostic criteria: Existing knowledge and future directions

Current diagnostic criteria for multiple sclerosis (MS) do not consider the optic nerve as a typical topography for establishing the diagnosis. Recent studies have proved the utility of optic nerve magnetic resonance imaging, optical coherence tomography and visual evoked potentials in detecting optic nerve lesions during the early stages of MS. In addition, emerging evidence supports the inclusion of optic nerve topography as a fifth region to fulfil the dissemination in space criteria. Anticipating a modification in the McDonald criteria, it is crucial for neurologists to familiarize with the diagnostic properties of each test in detecting optic nerve lesions and understand how to incorporate them into the MS diagnostic process. Therefore, the objective of this article is to review the existing evidence supporting the use of these tests in the diagnostic process of MS and provide a practical algorithm that can serve as a valuable guide for clinical practice.

Assignment Completed: The Optic Nerve Should Graduate to Be the Fifth Lesion Site for the Diagnosis of Multiple Sclerosis

Optic neuritis has long been considered a characteristic finding of multiple sclerosis and the initial manifestation of the disorder in about 25% of patients. Approximately 70% of patients will experience optic nerve dysfunction during their disease course.1.

A narrative review of neuro-ophthalmologic disease in African Americans and Hispanics with multiple sclerosis

Multiple sclerosis (MS) is the most common non-traumatic cause of disability in young people, with vision loss in the disease representing the second largest contributor to disability. In particular, African-American patients with MS are noted to have lower vision than their Caucasian counterparts. In this review, we examine the disparities in eye diseases in the MS population with our gaps in knowledge and discuss the underlying nature of pathological disparities.