Eyes are mirror of the brain: comparison of multiple sclerosis patients and healthy controls using OCT

Co-assessment of OCT-A and choroidal vascularity index data in multiple sclerosis patients

OBJECTIVE

To evaluate optical coherence tomography-angiography (OCT-A) findings and choroidal vascular index (CVI) in patients with multiple sclerosis (MS).

METHODS

113 patients, including multiple sclerosis patients with optic neuritis attack (MSON+) and no optic neuritis attack (MSON-) and healthy control group (HCG), participated in this cross-sectional study. OCT-A images of all patients were taken and CVI was calculated.

RESULTS

Superior flow (SF), deep flow (DF), foveal, and parafoveal superior vascular density (sVD) were decreased in the MSON+ group compared to HCG (p < 0.05). Optic disk flow (ODF) and optic disk head density (ONHD) values decreased in the MS group (p < 0.05). CVI was decreased in the MSON+ group compared to HCG (p < 0.05). There is a correlation between CVI and foveal and parafoveal sVD.

CONCLUSION

Non-invasive diagnostic tools such as OCT-A and CVI can be used for early diagnosis and follow-up of microvascular pathologies in inflammatory diseases such as MS.

The Evolvement of OCT and OCT-A in Identifying Multiple Sclerosis Biomarkers

The prevalence of multiple sclerosis (MS) has been increasing among young people in developing countries over the last years. With the continuous development of new technology, the diagnosis and follow-up of these patients has received new parameters that physicians may use in their practice. This paper reviews the main biomarkers identified through Optical Coherence Tomography Angiography (OCT-A) involved in the development and progression of MS and investigates the role it may have in detecting changes to the central nervous system (CNS).

Is the ganglion cell layer thickness to macular thickness ratio a new biomarker for multiple sclerosis?

PURPOSE

Ganglion cell layer thickness (GCLT)-to-total macular thickness (MT) is a new parameter that has not been studied in multiple sclerosis (MS) before. The current study aims to reveal the status of the GCLT-to-MT ratio in MS and its role in supporting the diagnosis of MS.

METHODS

In this retrospective and cross sectional study, the medical records of the MS patients between January 2016 and December 2021 were reviewed. Age-sex matched healthy control group was generated. Demographic and clinical data recorded. All participants were examined using a spectral-domain optic coherence tomography (OCT) device. Retinal layers, choroidal thickness (CT) was recorded. GCLT-to-MT ratio was calculated.

RESULTS

A total of 74 eyes of 37 MS (9 male,28 female) patients and 82 eyes of 41 control (13 male, 28 female) were included in the study. The mean age was 37 ± 9.0 (years) in MS group. The MS patients and the control group were compared in terms of OCT parameters, CT was thicker at all regions in MS patients (p < 0.001). Macular thickness, GCLT, and inner plexiform layer thickness (IPLT) were thinner than the control group (p < 0.05). For distinguishing MS patients from healthy subjects, AUROC values for central GCLT/MT, temporal GCLT/MT, superior GCLT/MT, nasal GCLT/MT, and inferior GCLT/MT were 0.717, 0.689, 0.694, 0.733, and 0.740, respectively.

CONCLUSIONS

In conclusion MT, GCLT, and IPLT thickness were thinner in MS patients, regardless of optic neuritis. The AUROC values of GCLT/MT were high and GCLT/MT ratio may be a helpful modality in demonstrating retinal neurodegeneration in MS patients.

Choroidal Thickness in Multiple Sclerosis: An Optical Coherence Tomography Study

Background and Purpose

To identify changes in the choroidal thickness (CT) in multiple sclerosis (MS) patients with and without optic neuritis (ON) using enhanced-depth-imaging optical coherence tomography (EDI-OCT).

Methods

This cross-sectional study included 96 eyes with MS and 28 eyes of healthy controls. All participants underwent an ophthalmologic examination and EDI-OCT scanning (Spectralis, Heidelberg Engineering, Germany) to assess the CT and the retinal nerve fiber layer (RNFL) thickness. MS patients were divided into two groups: 1) with and 2) without a history of ON. The CT was evaluated in the fovea and at six horizontal and six vertical points at 500, 1,000, and 1,500 µm from the fovea. Paired t-tests were used to compare the groups, and p-value<0.05 was considered as significant.

Results

At all 13 measurements points, the CT was thicker in MS patients than in the healthy controls and was thinner in eyes with ON than in the contralateral eyes, but these differences were not statistically significant. However, the CT was always larger in all points in eyes with a history of ON than in the control eyes. The RNFL was significantly thinner (p<0.05) in both MS and ON eyes than in the control eyes.

Conclusions

The CT did not differ between MS and control eyes, but it was significantly larger in patients with a history of ON, in whom the RNFL was thinner. Further studies are necessary to establish the possible role of the choroid in 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.

Optical coherence tomography angiography helps distinguish multiple sclerosis from AQP4-IgG-seropositive neuromyelitis optica spectrum disorder

INTRODUCTION

The aim was to characterize the optical coherence tomography (OCT) angiography measures in patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) and to evaluate their disease discrimination capacity.

METHODS

Patients with MS (n = 83) and AQP4-IgG-seropositive NMOSD (n = 91) with or without a history of optic neuritis, together with healthy controls (n = 34), were imaged. The main outcome measures were peripapillary retinal nerve fiber layer (pRNFL) thickness, macular ganglion cell-inner plexiform layer (GC-IPL) thickness, macular vessel density (VD), and perfusion density (PD) in the superficial capillary plexus. Diagnostic accuracy was assessed using the area under the receiver operating characteristics curve.

RESULTS

Compared with patients with MS, those with NMOSD had a significantly smaller average thickness of the pRNFL and GC-IPL (80.0 [59.0; 95.8] μm versus 92.0 [80.2; 101] μm, p < .001; 68.0 [56.0; 81.0] μm, versus 74.5 [64.2; 81.0] μm, p < .001) and significantly smaller whole VD and PD areas (15.6 [12.6; 17.0] mm^-1 versus 16.7 [14.8; 17.7] mm^-1 , p < .001; 0.38 [0.31; 0.42] mm^-1 versus 0.40 [0.37; 0.43] mm^-1 , p < .01). The combination of structural parameters (average thickness of the pRNFL and GC-IPL) with microvascular parameters (temporal-inner quadrant of VD, temporal-inner, nasal-inferior, and nasal-outer quadrant of PD) was revealed to have a good diagnostic capability for discriminating between NMOSD and MS.

CONCLUSIONS

OCT angiography reveals different structural and microvascular retinal changes in MS and AQP4-IgG-seropositive NMOSD. These combined structural and microvascular parameters might be promising biomarkers for disease diagnosis.

Bruch's membrane opening-minimum rim width: An alternative OCT biomarker study for multiple sclerosis

PURPOSE

Bruch's membrane opening-minimum rim width (BMO-MRW) and RNFL measured using anatomic positioning system (APS-RNFL) are novel OCT methods and remained unexplored in MS patients.To investigate the novel parameters of spectral-domain OCT as an alternative biomarker in patients with multiple sclerosis (MS).

METHODS

Retrospective cohort study; participants consisted of relapsing-remitting MS (RRMS) patients and healthy controls (HC). Eyes were classified according to the presence of MS and previous optic neuritis (ON). Measurements of standard peripapillary RNFL (S-RNFL), BMO-MRW, and APS-RNFL were performed.

RESULT

A total of 244 eyes of 122 participants (MS-patients: 63, HC: 59) were included in the study. Fifty-one eyes had a history of previous ON. In almost all measured parameters, neuroretinal rim thicknesses were observed the thinnest in eyes with ON history between all subgroups. S-RNFL and APS-RNFL techniques showed the difference in neuroretinal rim thickness in all three subjects (ON+, ON-, and HC). However, BMO-MRW, on the other hand, could not distinguish between ON(-) patients and HC. The relationship between OCT parameters and EDSS were observed only in eyes with an ON history in all three techniques. A meaningful model with 78% accuracy was obtained by using only the OCT parameters as risk factors. In the ROC analysis, no parameters were found to have acceptable high sensitivity and specificity. BMO-MRW was statistically weaker in every aspect than other RNFL techniques.

CONCLUSION

The novel APS-RNFL technique appears to be a bit more reliable alternative to S-RNFL technique to support therapeutic decision-making in MS. BMO-MRW has not been found as a successful alternative to S-RNFL.

Optic Nerve Head Changes in Patients with Optic Neuritis Secondary to Multiple Sclerosis: A Comparison of the Affected and Fellow Healthy Eyes

OBJECTIVE

To evaluate the thickness of lamina cribrosa (LC) in patients with multiple sclerosis (MS) using optical coherence tomography (OCT) and the effect of optic neuritis (ON) attack on these measurements during the remission period.

METHODS

The study included 20 cases diagnosed with relapsing-remitting MS with a history of ON attacks affecting one eye and in remission of MS and ON attacks for at least three months, and 28 randomly selected eyes of age- and sex-matched healthy controls. In the MS group, the eyes affected by ON attack were assigned as Group 1 (MS+ON), their fellow unaffected eyes as Group 2 (MS-ON), and healthy control eyes as Group 3. The LC, peripapillary retinal nerve fiber layer (ppRNFL), and subfoveal choroidal thickness measurements were made by using OCT in all cases, and results were compared between the groups.

RESULTS

The mean LC thickness in MS+ON and MS-ON groups was significantly lower than the control group (p<0.001). There was no significant difference between MS+ON and MS-ON groups in terms of mean LC thickness (p=0.073). The mean ppRNFL in the MS+ON and MS-ON groups was statistically significantly lower than the control group (p=0.003, p=0.035, respectively).

CONCLUSIONS

It is noteworthy that LC is significantly affected in eyes with MS who have not had a history of ON attack. Evaluation of the LC measurements can be important for early detection of optic nerve damage in patients with MS.

Serum neurofilament light chain and optical coherence tomography measures in MS: A longitudinal study

OBJECTIVE

To study the association between serum neurofilament light chain (sNfL) and multiple optical coherence tomography (OCT) measures in patients with MS and healthy controls (HCs).

METHODS

In this prospective study, 110 patients with MS were recruited, together with 52 age- and sex-matched HCs. Clinical evaluation and spectral domain OCT and sNfL were obtained at baseline and after 5.5 years of follow-up. Nested linear mixed models were used to assess differences between MS vs HC and associations between sNfL and OCT measures. Partial correlation coefficients are reported, and p values were adjusted for the false discovery rate.

RESULTS

At baseline, peripapillary retinal nerve fiber layer thickness (pRNFLT) and macular ganglion cell and inner plexiform layer thickness (mGCIP) were significantly lower in MS than HC both in MS-associated optic neuritis (MSON) (p = 0.007, p = 0.001) and nonaffected MSON (n-MSON) eyes (p = 0.003, p = 0.018), along with total macular volume (TMV) in n-MSON eyes (p = 0.011). At follow-up, MS showed significantly lower pRNFLT, mGCIP, and TMV both in MSON and n-MSON eyes (p < 0.001) compared with HC. In MS n-MSON eyes, sNfL was significantly associated with baseline pRNFLT and mGCIP (q = 0.019). No significant associations were found in MSON eyes.

CONCLUSIONS

This study confirms the ability of sNfL to detect neurodegeneration in MS and advocates for the inclusion of sNfL and OCT measures in clinical trials.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that sNfL levels were associated with MS neurodegeneration measured by OCT.