OCT and Visual Field Changes as Useful Markers for Follow-up of Axonal Loss in Multiple Sclerosis in Egyptian Patients

Retinal changes in multiple sclerosis: An optical coherence tomography and angiography study

BACKGROUND

Multiple sclerosis (MS) is an autoimmune demyelinating disease of the central nervous system with neuroaxonal damage. It is the principal driver of non-traumatic disability in young adults. Visual symptoms are common and optic neuritis (ON) may be the revealing feature in up to 30% of cases. Structural optical coherence tomography (OCT) represents a biomarker of central nervous system neurodegeneration in MS. OCT-angiography (OCT-A) is a noninvasive tool allowing the study of retinal vasculature and the detection of microvascular damage in neuro-retinal diseases. In this study, we aimed to assess structural and microvascular retinal changes in patients with MS with and without ON and to correlate the findings with visual function and MS disability.

METHODS

We conducted a cross-sectional study including patients diagnosed with MS according to the 2017 McDonald criteria. All patients underwent complete neurological examination with evaluation of the Expanded Disability Status Scale (EDSS) and the Multiple Sclerosis Severity Score (MSSS) and an ophthalmological examination including OCT and OCT-A. Patients were compared with age- and sex-matched healthy subjects. The primary endpoints were assessment of retinal nerve fiber layer (RNFL) thickness, ganglion cell layer (GCL+), and ganglion cell complex (GCL++) thicknesses on OCT. Vascular densities in the superficial capillary plexus (SCP), deep capillary plexus (DCP), and choriocapillaris (CC) were assessed on OCT-A, as well as central avascular zone (CAZ) parameters, lacunarity and fractal dimension.

RESULTS

A total of 160 MS eyes with and without a previous history of ON and 64 age- and gender-matched healthy eyes were analyzed. Among 160 eyes with MS, 69 had a history of ON. We observed a decrease in RNFL and GCL++ thickness in all 12 quadrants in MS patients when compared to healthy controls. Multivariate analysis by linear regression noted a significant correlation for temporal GCL++ and inferonasal RNFL thickness that were decreased in the MS group. A greater decrease in retinal layers thickness was identified in MS patients with a history of ON. On OCT-A, vascular density in (SCP) was significantly reduced in the MS group (P<0.002). A significant correlation between RNFL thickness and retinal vascular density was found but only in less than half of the hourly quadrants. A significant correlation was noted between visual acuity and CC density (P<0.0001). We also noted an inverse correlation between EDSS scores and CC density (P=0.02 and r=-0.275) and between MSSS and RNFL/GCL++ thicknesses.

CONCLUSIONS

RNFL and GCL++ layers were thinner in MS patients with a history of ON and were reversely correlated with disease severity. Moreover, retinal vascular changes were observed in MS even in eyes without ON, and CC was reversely correlated with visual function and current disability. Thus, structural OCT coupled with OCT-A could represent a noninvasive and dynamic biomarker of MS severity and progression.

Retinal optical coherence tomography measures in multiple sclerosis: a systematic review and meta-analysis

Spectral domain-optical coherence tomography plays a crucial role in the early detection and monitoring of multiple sclerosis (MS) pathophysiology. We aimed to quantify differences in retinal layer measures among different groups of MS and explored different variables that correlate with retinal measures. This study was reported according PRISMA guidelines. A comprehensive search was done across PubMed, Embase, and Google Scholar. The mean difference in thickness of retinal layers and macular volume was assessed. Meta-regression was done to assess the sources of heterogeneity. A total of 100 articles were included in the meta-analyses. The peripapillary retinal nerve fiber layer (pRNFL) thickness significantly decreased in the MSON (MD: -16.44, P < 0.001), MSNON (MD: -6.97, P < 0.001), and PMS (MD: -11.35, P < 0.001) versus HC. The macular RNFL was lower among the MSON (MD: -6.24, P = 0.013) and MSNON (MD: -3.84, P <0.001) versus HC. Macular ganglion cell layer and inner plexiform layer (GCIPL) was thinner among MSON (MD: -14.83, P <0.001), MSNON (MD: -6.38, P < 0.001), and PMS (MD: -11.52, P < 0.001) compared with control eyes. Inner nuclear layer (INL) was higher in the MSON (MD: 0.49, P < 0.001) versus HC. Outer nuclear layer (ONL) thickness significantly lower in the MSNON (MD: -1.15, P = 0.019) versus HC. Meta-regression showed that disease duration, age, EDSS score, and percentage of patients taking DMT are all negatively correlated with pRNFL and GCIPL thickness; however, female gender was correlated with less atrophy. As conclusion, the study highlights substantial thinning in the pRNFL and macular GCIPL between MS versus controls. INL as valuable parameter for capturing inflammatory disease activity.

[Uveitis and multiple sclerosis : Clinical aspects, diagnostics, management and treatment]

Approximately 0.5-1% of patients with multiple sclerosis (MS) have co-existing uveitis. Both intraocular inflammation and MS mainly affect women in younger adulthood. The MS in patients is most frequently associated with an often bilateral intermediate uveitis with typical concomitant retinal vasculitis. Both diseases share similar characteristics with chronic inflammatory diseases with a relapsing course and an immune-mediated pathogenesis; however, it is still unclear whether the co-occurrence of uveitis and MS in the same patient represents a coincidence of two separate disease entities or whether uveitis is a rare clinical manifestation of MS. In the differential diagnostics of intermediate uveitis, clinical symptoms and signs of MS should be considered. As both diseases are considered to be immune-mediated, immunotherapy is the main treatment option. In recent years the range of medications has expanded and includes several disease modifying drugs (biologics). When selecting the active substance it must be taken into account that tumor necrosis factor (TNF) alpha blockers are contraindicated in patients with MS.

Significant retinal microvascular impairments in multiple sclerosis assessed through optical coherence tomography angiography

PURPOSE

Multiple sclerosis (MS) is associated with different ocular disorders. This study aimed to investigate the retinal microvascular changes detected by optical coherence tomography angiography (OCTA) in eyes with MS with or without a history of optic neuritis (ON).

METHODS

A comprehensive literature search was conducted in the Web of Science, Embase, PubMed, and Cochrane Library databases on September 26, 2021 for articles focused on OCTA manifestations in the eyes of MS patients compared with healthy controls. RevMan Manager (v.5.4) and Stata (v.14.1) were used to analyze the main differences and publication risks. Weighted mean differences and 95% confidence intervals were calculated for continuous estimates. This study also included subgroup analysis between three groups: eyes with multiple sclerosis and with optic neuritis (MSON); eyes with multiple sclerosis and without optic neuritis (MSNON); and healthy controls.

RESULTS

Thirteen studies with a total of 1803 eyes were identified, including 957 eyes with MS and 846 eyes of healthy controls. The vessel density of the MS eyes decreased significantly in most areas of the radial peripapillary capillary. A marked reduction in the macular superficial capillary plexus of MS eyes regardless of ON history was also confirmed.

CONCLUSION

The results suggest that MS patients demonstrated significant retinal microvasculature impairment regardless of ON history, compared to healthy controls. Retinal vessel density attenuation detected by OCTA may serve as a reliable early marker of MS.

Detailed Evaluation of Macular Ganglion Cell Complex in Patients with Multiple Sclerosis

Introduction:

Retinal nerve fiber layer thickness has been used for monitoring of disease activity in patients with multiple sclerosis (MS). Macular ganglion cell complex (GCC) layer of retina also can be measured by OCT and has been suggested as a potential biomarker in MS. In this study we investigated the macular GCC and its role as a potential biomarker in patients with Multiple Sclerosis (MS).

Methods:

A prospective cohort-study, subjects consisted of Relapsing-Remitting MS patients (n=62) and healthy controls (n=60). Eyes of MS patients were divided into two subgroups according to the history of the optic neuritis (ON). Standard peripapillary-RNFL and macular scan protocol, and retinal auto-segmentation of spectral-domain OCT were performed. Macular RNFL (mRNFL), ganglion cell layer (GCL), and inner plexiform layer (IPL), and GCC (the sum of these former three layers) were recorded. The macula was divided into nine sectors using the ETDRS grid (4×9=36 variables).

Results:

In total, 50 eyes of 36 patients had previous ON attacks. 35/36 GCC parameters were thinner in MS patients and subgroups compared to the control group (p<0.05). When the eyes with and without a history of optic neuritis were compared, 25 of 36 parameters were thinner in those with ON. There were strong correlations between visual acuity-GCC parameters and EDSS scores in patients with a history of optic neuritis. However, no such relationship was found in those without an ON story.

Conclusion:

Ganglion cell complex gets thinner in patients with MS with a decreasing order of GCL, IPL, and mRNFL. The examination of GCC in detail could be a beneficial biomarker for MS.

Ocular fixation and macular integrity by microperimetry in multiple sclerosis

PURPOSE

To characterize the fixation and macular integrity of subjects with multiple sclerosis (MS) with and without previous optic neuritis (ON) using microperimetry (MP).

METHODS

Fifty-five eyes of MS patients, subdivided into three groups (28 eyes without ON, 16 with previous ON, and 11 eyes with previous ON in the contralateral eye), and 43 healthy eyes were enrolled (January-November 2018). All cases were evaluated using the MAIA microperimeter (Centervue), analyzing the following parameters: average macular threshold (AT), fixation indexes (P1 and P2), bivariate contour ellipse area (BCEA) for 95% and 63% of points, and horizontal (H) and vertical (V) axes of the ellipse of fixation.

RESULTS

All MS groups showed a significant reduced AT compared with the control group (p < 0.001). This reduction was more representative (p < 0.001) in eyes with previous ON. No statistically significant differences were found between MS patients with and without previous ON (p > 0.05). Mean AT was correlated with the examination time in all three groups (between ρ = - 0.798 p < 0.001 and ρ = - 0.49 p < 0.001). Significant differences in fixation parameters were only found between control and MS with ON groups (p < 0.02). The ratio of the disease showed a significant correlation with fixation parameters in MS groups (p < 0.02), but not with AT.

CONCLUSIONS

In MS patients, macular sensitivity is altered, especially in eyes with previous ON. Likewise, a fixational instability is present in MS patients with ON, with more increase of the V axis of the fixation area than of the H. The ratio of the disease also affects the patient fixation pattern.

Retinal correlates of neurological disorders

Considering the retina as an extension of the brain provides a platform from which to study diseases of the nervous system. Taking advantage of the clear optical media of the eye and ever-increasing resolution of modern imaging techniques, retinal morphology can now be visualized at a cellular level in vivo. This has provided a multitude of possible biomarkers and investigative surrogates that may be used to identify, monitor and study diseases until now limited to the brain. In many neurodegenerative conditions, early diagnosis is often very challenging due to the lack of tests with high sensitivity and specificity, but, once made, opens the door to patients accessing the correct treatment that can potentially improve functional outcomes. Using retinal biomarkers in vivo as an additional diagnostic tool may help overcome the need for invasive tests and histological specimens, and offers the opportunity to longitudinally monitor individuals over time. This review aims to summarise retinal biomarkers associated with a range of neurological conditions including Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS), amyotrophic lateral sclerosis (ALS) and prion diseases from a clinical perspective. By comparing their similarities and differences according to primary pathological processes, we hope to show how retinal correlates can aid clinical decisions, and accelerate the study of this rapidly developing area of research.

Peripapillary retinal nerve fiber layer and ganglion cell complex degeneration in Egyptian patients with bipolar disorder

PURPOSE

To determine if changes in OCT parameters including peripapillary RNFL thickness and GCC thickness in Egyptian patients with bipolar disorder exist, and to correlate them with disease severity and clinical characteristics.

METHODS

A case-control study conducted on 40 patients with bipolar disorder were compared to 40 matched healthy controls. Both patients and controls were subjected to ophthalmic examination including: BCVA, slit-lamp examination, fundus examination, and OCT imaging. Patients were also subjected to Young Mania Rating Scale (YMRS).

RESULTS

Thinning of average (RNFL) and average (GCC) thickness of right and left eye in patients with BPD (whether received electroconvulsive therapy or not) when compared with control subjects. Number of episodes, age at onset and severity of disease showed insignificant correlation with OCT parameters.

CONCLUSIONS

Significant degenerative changes were detected by OCT in patients with bipolar disorder that were not affected by receiving ECT and not related to disease severity or duration.

Retinal layer segmentation in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND

Structural retinal imaging biomarkers are important for early recognition and monitoring of inflammation and neurodegeneration in multiple sclerosis. With the introduction of spectral domain optical coherence tomography (SD-OCT), supervised automated segmentation of individual retinal layers is possible. We aimed to investigate which retinal layers show atrophy associated with neurodegeneration in multiple sclerosis when measured with SD-OCT.

METHODS

In this systematic review and meta-analysis, we searched for studies in which SD-OCT was used to look at the retina in people with multiple sclerosis with or without optic neuritis in PubMed, Web of Science, and Google Scholar between Nov 22, 1991, and April 19, 2016. Data were taken from cross-sectional cohorts and from one timepoint from longitudinal studies (at least 3 months after onset in studies of optic neuritis). We classified data on eyes into healthy controls, multiple-sclerosis-associated optic neuritis (MSON), and multiple sclerosis without optic neuritis (MSNON). We assessed thickness of the retinal layers and we rated individual layer segmentation performance by random effects meta-analysis for MSON eyes versus control eyes, MSNON eyes versus control eyes, and MSNON eyes versus MSON eyes. We excluded relevant sources of bias by funnel plots.

FINDINGS

Of 25 497 records identified, 110 articles were eligible and 40 reported data (in total 5776 eyes from patients with multiple sclerosis [1667 MSON eyes and 4109 MSNON eyes] and 1697 eyes from healthy controls) that met published OCT quality control criteria and were suitable for meta-analysis. Compared with control eyes, the peripapillary retinal nerve fibre layer (RNFL) showed thinning in MSON eyes (mean difference -20·10 μm, 95% CI -22·76 to -17·44; p<0·0001) and in MSNON eyes (-7·41 μm, -8·98 to -5·83; p<0·0001). The macula showed RNFL thinning of -6·18 μm (-8·07 to -4·28; p<0·0001) in MSON eyes and -2·15 μm (-3·15 to -1·15; p<0·0001) in MSNON eyes compared with control eyes. Atrophy of the macular ganglion cell layer and inner plexiform layer (GCIPL) was -16·42 μm (-19·23 to -13·60; p<0·0001) for MSON eyes and -6·31 μm (-7·75 to -4·87; p<0·0001) for MSNON eyes compared with control eyes. A small degree of inner nuclear layer (INL) thickening occurred in MSON eyes compared with control eyes (0·77 μm, 0·25 to 1·28; p=0·003). We found no statistical difference in the thickness of the combined outer nuclear layer and outer plexiform layer when we compared MSNON or MSON eyes with control eyes, but we found a small degree of thickening of the combined layer when we compared MSON eyes with MSNON eyes (1·21 μm, 0·24 to 2·19; p=0·01).

INTERPRETATION

The largest and most robust differences between the eyes of people with multiple sclerosis and control eyes were found in the peripapillary RNFL and macular GCIPL. Inflammatory disease activity might be captured by the INL. Because of the consistency, robustness, and large effect size, we recommend inclusion of the peripapillary RNFL and macular GCIPL for diagnosis, monitoring, and research.

FUNDING

None.