Evaluation of Optical Coherence Tomography Angiography Findings in Pars Planitis and Multiple Sclerosis Associated Intermediate Uveitis in Remission

PURPOSE

To evaluate the microvasculature during remission in patients with pars planitis (PP-IU) and multiple sclerosis-associated intermediate uveitis (MS-IU) using optical coherence tomography angiography (OCT-A).

METHODS

Single-center, descriptive, case-control study was conducted. Adult patients (≥16 years) with IU in remission (PP-IU and MS-IU) and healthy age-sex matched healthy controls (HC) were enrolled to the study. Demographic/clinical features, best-corrected visual acuity (BCVA), ocular findings, neurological symptoms and preferred treatments were recorded. The presence of cystoid macular edema (CME) during follow-up was recorded. All IU patients in remission and HC subjects were scanned with OCT-A. Foveal avascular zone (FAZ) areas of superficial and deep capillary plexus (SCP/DCP) and vascular densities of SCP, DCP and choriocapillaris were obtained from OCT-A and compared between the groups.

RESULTS

Sixty-nine eyes of 37 IU patients in remission and 20 HC were included (44 eyes/23 patients in PP-IU, 25/14 in MS-IU, 40/20 in HC). No statistically significant differences were observed in terms of demographic or clinical characteristics of the patients. The vascular density in the SCP was significantly reduced in the PP-IU and MS-IU groups compared to the HC group (p < .05). Nevertheless, there were no significant changes in any of the OCTA parameters between the IU groups. Uveitis duration was found to be correlated with enlargement of the FAZ area in PP-IU (p = .039).

CONCLUSION

OCTA may not be useful in differentiating between PP-IU and MS-IU. Nevertheless, the primary implication in SCP potentially elucidates the pathogenesis of these two subtypes of IU, which are characterized by a shared pathogenesis. The monitoring of the FAZ area in the PP-IU group is valuable in terms of chronicity.

Optical coherence tomography angiography as a potential tool in differential diagnosis of multiple sclerosis and rheumatic disorders with central nervous system involvement

PURPOSE

The aim of this study is to analyse whether optical coherence tomography angiography (angio-OCT, OCTA) measurements can be a useful tool to differentiate central nervous system (CNS) involvement in rheumatic disorders (RD) from multiple sclerosis (MS).

METHODS

A total of 85 patients- 41 with MS, 21 with RD with CNS involvement and 23 healthy controls were included in the study. All individuals underwent OCTA and the following parameters were measured in each eye separately: average foveal and parafoveal vessel density (VD), average foveal and parafoveal vessel length (VL) of the superficial capillary plexus (SCP) and deep capillary plexus (DCP), as well as area, perimeter, and circularity of the foveal avascular zone.

RESULTS

OCTA showed a VD reduction in the foveal region of the SCP in eyes of RD patients when compared to MS patients (21.96 ± 3.39 vs.23.88 ± 3.05 (p = 0.003)). There have been no significant differences in any of the assessed parameters that is average VD and total average VL in the foveal area of the SCP as well as of the DCP in the general population comprising healthy controls, MS and RD groups (p > 0.05 for all).

CONCLUSIONS

Our results suggest that an OCTA finding of decreased VD in the foveal region of the SCP may be considered as a potentially useful biomarker of RD in comparison with MS patients.

Optical Coherence Tomography Advanced Parameters in Patients With Multiple Sclerosis: Ophthalmological and Neurological Assessments

PURPOSE

To evaluate ophthalmological, neurological, radiological, and laboratory data in patients with multiple sclerosis (MS) and to identify new ophthalmological factors that could be helpful as biomarkers of the disease, potentially leading to an earlier prediction of disease course and disability progression.

DESIGN

Retrospective, cross-sectional-study.

METHODS

Best-corrected visual acuity (BCVA), ophthalmological biomicroscopy of the anterior segment and fundus, structural optical coherence tomography (OCT) with retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC), and OCT angiography (OCTA) with vascular density (VD) were performed. The following clinical and neuro-radiological features were assessed: MS phenotype, disease duration, clinical severity, type of treatment, and T2-weighted lesion and T1-weighted Gd+ enhancing lesion number on the brain and spinal cord MRI.

RESULTS

One hundred and six patients (212 eyes) were analyzed. Sixty-six of them (62.2%) had MS and 40 (37.8%) were matched healthy controls (HCs). patients with MS showed lower RNFL, GCC, and VD in the radial peripapillary capillary plexus than controls in both eyes (P < .05). By Performing a logistic regression with a distinct MS outcome for both eyes, we were able to demonstrate that the value that was most predictive of MS was the average GCC thickness (P = .009). Regression analysis demonstrated that patients with a higher T2-weighted lesions showed a lower RNFL thickness value and reduced GCC and VD values than those with a low lesion load (P < .01 and P < .05, respectively). Similarly, relapsing MS patients showed lower RNFL values (P < .05).

CONCLUSIONS

Several OCT and OCTA-optic nerve parameters could be useful prognostic biomarkers for the MS disease course in clinical practice. However, it is necessary to do additional research with larger sample sizes in order to validate these findings.

Retinal vascular density as a potential biomarker of diabetic cerebral small vessel disease

AIM

The retina and brain share similar anatomical and physiological features. Thus, retinal imaging by optical coherence tomography angiography (OCTA) might be a potential tool for the early diagnosis of diabetic cerebral small vessel disease (CSVD). In this study, we aimed to evaluate retinal vascular density (VD) in diabetic CSVD by OCTA imaging and explore the associations between retinal VD and cerebral magnetic resonance imaging (MRI) markers and cognitive function.

METHODS

In total, 131 patients were enrolled, including CSVD (n = 43) and non-CSVD groups (n = 88). The VD and foveal avascular zone of the retinal capillary plexus were measured with OCTA. A brain MRI was performed.

RESULTS

MRI imaging showed that in the diabetic CSVD group, white matter hyperintensities (WMHs), particularly deep WMHs (58.82%), are the most common MRI marker, followed by cerebral microbleeds in the subtentorial and cortical areas (34.78%). The CSVD group showed increases in the prevalence of cognitive dysfunction (p = .034) and depression (p = .033) and decreases in visuospatial/executive ability and delayed recall ability. In the CSVD group, VDs of the macular superficial vascular plexus (32.93 ± 7.15% vs. 36.97 ± 6.59%, p = .002), intermediate capillary plexus (20.87 ± 4.30% vs. 23.08 ± 4.30%, p = .005) and deep capillary plexus (23.54 ± 5.00% vs. 26.05 ± 4.20%, p = .003) were lower than those of the non-CSVD group. Multiple linear regression analysis showed that VD of the macular superficial vascular plexus was independently associated with cerebral microbleeds. Meanwhile, VD of the macular intermediate capillary plexus was associated with white matter lacunar infarcts after adjustment.

CONCLUSIONS

Diabetic CSVDs are characterized by MRI markers, including deep WMHs and cerebral microbleeds, and showed impaired cognition with decreased visuospatial/executive ability and delayed recall ability. OCTA imaging revealed a significant decrease in retinal microvascular perfusion in diabetic CSVD, which was related to MRI markers and cognitive function. OCTA might be a valuable potential measurement for the early diagnosis of CSVD.

Retinal and Choroidal Vascularity Evaluation in Pediatric Radiologically Isolated Syndrome and Multiple Sclerosis

BACKGROUND

To assess vessel density (VD) and flow of retinal plexuses and peripapillary region related with the pediatric radiologically isolated syndrome (RIS) and multiple sclerosis (MS).

METHODS

We analyzed 24 eyes of 12 participants with the diagnosis of RIS, 24 eyes of 12 participants with the diagnosis of MS, and 26 eyes of 13 age- and sex-matched healthy controls in this prospective, cross-sectional study. The superficial capillary plexus (SCP) and deep capillary plexus, foveal avascular zone, and the flow of choriocapillaris were investigated using optical coherence tomography angiography.

RESULTS

Parafoveal VD and all subregion parameters in SCP were significantly decreased in the MS group compared with the controls, whereas only nasal and inferior VD were significantly decreased in the pediatric RIS group compared with the controls. Ganglion cell layer (GCL) thickness of all subregions of the inner ring was significantly decreased in the pediatric MS group compared with the control group. No significant difference was observed between the pediatric RIS group and the control group regarding thickness.

CONCLUSIONS

We showed lower parafoveal VD in all subregions of SCP in pediatric MS, whereas only parafoveal nasal and inferior VD were decreased in pediatric RIS. GCL thickness of inner ring was significantly decreased in the pediatric MS, whereas GCL thickness did not change in pediatric RIS. Therefore, a decrease of parafoveal nasal and inferior VD without a decrease in thickness implies an early impairment of microvasculature in the RIS before impairment of thickness and that microvascular alterations begin from highly vascular superficial parafovea.

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.

Optical Coherence Tomography Angiography: Revolutionizing Clinical Diagnostics and Treatment in Central Nervous System Disease

Optical coherence tomography angiography (OCTA), as a new generation of non-invasive and efficient fundus imaging technology, can provide non-invasive assessment of vascular lesions in the retina and choroid. In terms of anatomy and development, the retina is referred to as an extension of the central nervous system (CNS). CNS diseases are closely related to changes in fundus structure and blood vessels, and direct visualization of fundus structure and blood vessels provides an effective "window" for CNS research. This has important practical significance for identifying the characteristic changes of various CNS diseases on OCTA in the future, and plays a key role in promoting early screening, diagnosis, and monitoring of disease progression in CNS diseases. This article reviews relevant fundus studies by comparing and summarizing the unique advantages and existing limitations of OCTA in various CNS disease patients, in order to demonstrate the clinical significance of OCTA in the diagnosis and treatment of CNS diseases.

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.

Association of retinal vessel pathology and brain atrophy in relapsing-remitting multiple sclerosis

Background

Optical coherence tomography angiography (OCTA) allows non-invasive assessment of retinal vessel structures. Thinning and loss of retinal vessels is evident in eyes of patients with multiple sclerosis (MS) and might be associated with a proinflammatory disease phenotype and worse prognosis. We investigated whether changes of the retinal vasculature are linked to brain atrophy and disability in MS.

Material and methods

This study includes one longitudinal observational cohort (n=79) of patients with relapsing-remitting MS. Patients underwent annual assessment of the expanded disability status scale (EDSS), timed 25-foot walk, symbol digit modalities test (SDMT), retinal optical coherence tomography (OCT), OCTA, and brain MRI during a follow-up duration of at least 20 months. We investigated intra-individual associations between changes in the retinal architecture, vasculature, brain atrophy and disability. Eyes with a history of optic neuritis (ON) were excluded.

Results

We included 79 patients with a median disease duration of 12 (interquartile range 2 - 49) months and a median EDSS of 1.0 (0 - 2.0). Longitudinal retinal axonal and ganglion cell loss were linked to grey matter atrophy, cortical atrophy, and volume loss of the putamen. We observed an association between vessel loss of the superficial vascular complex (SVC) and both grey and white matter atrophy. Both observations were independent of retinal ganglion cell loss. Moreover, patients with worsening of the EDSS and SDMT revealed a pronounced longitudinal rarefication of the SVC and the deep vascular complex.

Discussion

ON-independent narrowing of the retinal vasculature might be linked to brain atrophy and disability in MS. Our findings suggest that retinal OCTA might be a new tool for monitoring neurodegeneration during MS.

Optical coherence tomography (OCT) measurements and disability in multiple sclerosis (MS): A systematic review and meta-analysis

BACKGROUND

Studies have demonstrated that people with multiple sclerosis (pwMS) experience visual impairments and neurodegenerative retinal processes. The disability progression in pwMS may be associated with retinal changes assessed with optical coherence tomography (OCT). This meta-analysis aims at synthesizing the correlations between OCT measurements of disability in pwMS.

METHODS

We systematically searched four databases (PubMed/MEDLINE, Embase, Scopus, and Web of Science) from inception to November 2022, then conducted a meta-analysis using a random effects model to determine the pooled correlation coefficient(r) between OCT measurements and disability scales by R version 4.2.3 with the meta version 6.2-1 package.

RESULTS

From 3129 studies, 100 studies were included. Among 9051 pwMS, the female-to-male ratio was 3.15:1, with a mean age of 39.57 ± 6.07 years. The mean disease duration and Expanded Disability Status Scale (EDSS) were 8.5 ± 3.7 and 2.7 ± 1.1, respectively. Among the pooled subgroup analyses, macular ganglion cell inner plexiform layer (mGCIPL) in patients with relapsing-remitting (pwRRMS) and peripapillary retinal nerve fiber layer (pRNFL) in patients with progressive MS (pwPMS) had strong correlations with EDSS, r = -0.33 (95% CI: -0.45 to -0.20, I2 = 45%, z-score = -4.86, p < 0.001) and r = -0.20 (95% CI:-0.58 to 0.26, I2 = 76%, z-score = -0.85, p = 0.395), respectively. According to subgroup analysis on pwMS without optic neuritis (ON) history, the largest correlation was seen between EDSS and macular ganglion cell complex (mGCC): r = -0.39 (95% CI: -0.70 to 0.04, I2 = 79%, z-score = -1.79, p = 0.073).

CONCLUSION

OCT measurements are correlated with disability in pwMS, and they can complement the comprehensive neurological visit as an additional paraclinical test.

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).

Combining retinal structural and vascular measurements improves discriminative power for multiple sclerosis patients

Data on how retinal structural and vascular parameters jointly influence the diagnostic performance of detection of multiple sclerosis (MS) patients without optic neuritis (MSNON) are lacking. To investigate the diagnostic performance of structural and vascular changes to detect MSNON from controls, we performed a cross-sectional study of 76 eyes from 51 MS participants and 117 eyes from 71 healthy controls. Retinal macular ganglion cell complex (GCC), retinal nerve fiber layer (RNFL) thicknesses, and capillary densities from the superficial (SCP) and deep capillary plexuses (DCP) were obtained from the Cirrus AngioPlex. The best structural parameter for detecting MS was compensated RNFL from the optic nerve head (AUC = 0.85), followed by GCC from the macula (AUC = 0.79), while the best vascular parameter was the SCP (AUC = 0.66). Combining structural and vascular parameters improved the diagnostic performance for MS detection (AUC = 0.90; p<0.001). Including both structure and vasculature in the joint model considerably improved the discrimination between MSNON and normal controls compared to each parameter separately (p = 0.027). Combining optical coherence tomography (OCT)-derived structural metrics and vascular measurements from optical coherence tomography angiography (OCTA) improved the detection of MSNON. Further studies may be warranted to evaluate the clinical utility of OCT and OCTA parameters in the prediction of disease progression.

Retinal Vascular Density Using Optical Coherence Tomography-Angiography in Optic Neuritis

The aim of this study is to access the perifoveolar and peripapillary vascular density (VD) using optical coherence tomography-angiography (OCT-A) in eyes with optic neuritis (ON) and in fellow eyes, then compare that to healthy controls.

METHOD

This is a cross-sectional study including 22 patients with unilateral ON and 20 control eyes of healthy subjects. A complete clinical examination and OCT-A were performed at least 6 months after the acute episode of optic neuritis. Vascular plexuses of the peripapillary and perifoveolar images obtained from OCT-A were used to calculate the VD in each plexus: superficial, deep, and peripapillary capillaries for each group (ON eyes, fellow eyes, healthy eyes).

RESULTS

Compared to healthy control eyes, in the peripapillary area, we found a significant decrease in VD not only in ON eyes but also in fellow eyes in average (p ≤ 0.05) and in the temporal sector (p < 0.001). In the perifoveolar area, the VD of the superficial capillary plexus is decreased in all sectors (p < 0.001) in ON eyes and only in the upper sector (p = 0.037) of fellow eyes compared to control eyes. VD correlates with ganglion cell layer (GCL) thickness in ON and in fellow eyes.

CONCLUSION

Peripapillary vascular density is decreased in both affected eyes and fellow eyes after a unilateral episode of optic neuritis, suggesting a subclinical involvement of the disease. Further studies are needed to clarify the mechanism and clinical implications of these data.

International Olympic Committee (IOC) consensus paper on sports-related ophthalmology issues in elite sports

Vision plays an important role in an athletes' success. In sports, nearly 80% of perceptual input is visual, and eye health and sports medicine are closely intertwined fields of utmost importance to athletes. The physical nature of sports activities renders individuals more prone to various eye injuries than the general population. Ocular trauma can lead to lifelong sequelae, and impaired vision requires careful follow-up and management. Apart from injuries, athletes may also experience vision problems that can hamper their performance, including blurred vision, double vision, and light sensitivity. The interdisciplinary nature of sports medicine necessitates collaboration between sports medicine professionals and ophthalmologists. Through such collaborations, athletes can receive appropriate eye care, education on proper eye protection and guidance on adopting good eye health practices. If any inconspicuous symptoms are not detected and treated promptly, athletes may acquire systemic injuries because of defective vision, preventing them from achieving high level athletic performance in competitions. The protection of the elite athlete is the responsibility of all of us in sports medicine. To advance a more unified, evidence-informed approach to ophthalmic health assessment and management in athletes and as relevant for sports medicine physicians, the International Olympic Committee Consensus Group aims for a critical evaluation of the current state of the science and practice of ophthalmologic issues and illness in high-level sports, and present recommendations for a unified approach to this important issue.

Utility of the visual system to monitor neurodegeneration in multiple sclerosis

Neurodegeneration occurs early in the multiple sclerosis (MS) disease course and is an important driver of permanent disability. Current immunomodulatory therapies do not directly target neuronal health; thus, there is a critical need to develop neuroprotective strategies in MS. Outcome measures in clinical trials primarily evaluate disease activity and clinical disability scores rather than measures of neurodegeneration. The visual system provides a noninvasive correlate of brain atrophy and neuronal function through structural and functional exams. Furthermore, optic nerve axons and their respective neuronal cell bodies in the retina, in addition to their synaptic input to the thalamus, provide a distinct anatomy to investigate neurodegenerative processes. This review discusses the utility of the visual system as an early output measure of neurodegeneration in MS as well as an important platform to evaluate neuroprotective strategies in preclinical models.

Optical coherence tomography angiography measurements in multiple sclerosis: a systematic review and meta-analysis

BACKGROUND AND OBJECTIVES

Recent literature on multiple sclerosis (MS) demonstrates the growing implementation of optical coherence tomography-angiography (OCT-A) to discover potential qualitative and quantitative changes in the retina and optic nerve. In this review, we analyze OCT-A studies in patients with MS and examine its utility as a surrogate or precursor to changes in central nervous system tissue.

METHODS

PubMed and EMBASE were systematically searched to identify articles that applied OCT-A to evaluate the retinal microvasculature measurements in patients with MS. Quantitative data synthesis was performed on all measurements which were evaluated in at least two unique studies with the same OCT-A devices, software, and study population compared to controls. A fixed-effects or random-effects model was applied for the meta-analysis based on the heterogeneity level.

RESULTS

The study selection process yielded the inclusion of 18 studies with a total of 1552 evaluated eyes in 673 MS-associated optic neuritis (MSON) eyes, 741 MS without optic neuritis (MSNON eyes), and 138 eyes without specification for the presence of optic neuritis (ON) in addition to 1107 healthy control (HC) eyes. Results indicated that MS cases had significantly decreased whole image superficial capillary plexus (SCP) vessel density when compared to healthy control subjects in the analyses conducted on Optovue and Topcon studies (both P < 0.0001). Likewise, the whole image vessel densities of deep capillary plexus (DCP) and radial peripapillary capillary (RPC) were significantly lower in MS cases compared to HC (all P < 0.05). Regarding optic disc area quadrants, MSON eyes had significantly decreased mean RPC vessel density compared to MSNON eyes in all quadrants except for the inferior (all P < 0.05). Results of the analysis of studies that used prototype Axsun machine revealed that MSON and MSNON eyes both had significantly lower ONH flow index compared to HC (both P < 0.0001).

CONCLUSIONS

This systematic review and meta-analysis of the studies reporting OCT-A measurements of people with MS confirmed the tendency of MS eyes to exhibit reduced vessel density in the macular and optic disc areas, mainly in SCP, DCP, and RPC vessel densities.

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.

Microvascular impairments detected by optical coherence tomography angiography in multiple sclerosis patients: A systematic review and meta-analysis

Purpose

A systematic review and meta-analysis was conducted to investigate changes in retinal and choroidal microvasculature in patients with multiple sclerosis (MS) using optical coherence tomography angiography (OCTA).

Methods

PubMed and Google Scholar were searched for studies that compared retinal and choroidal microvasculature between MS and healthy controls (HC) with OCTA. MS patients were divided into 2 groups: MS with (MSON) or without optic neuritis (MSNON).

Results

Totally, 13 studies including 996 MS eyes and 847 HC eyes were included. Compared with the HC, the vessel density of the whole superficial vascular complex (SVC) was reduced by 2.27% and 4.30% in the MSNON and MSON groups, respectively. The peripapillary vessel density was 2.28% lower and 4.96% lower in the MSNON and MSON groups, respectively, than in the HC. Furthermore, the MSON group had significant lower vessel density of the SVC (mean difference [MD] = -2.17%, P < 0.01) and lower peripapillary vessel density (MD = -2.02%, P = 0.02) than the MSNON group. No significant difference was found in the deep vascular complex or choriocapillaris densities among MSNON, MSON or HC groups (P > 0.05). Meta-regression analyses suggested that illness duration and the Expanded Disability Status Scale scores of MS patients were possible sources of heterogeneity (P < 0.05).

Conclusion

The retinal SVC and peripapillary vessel density decreased significantly in MS eyes, especially in eyes with optic neuritis. Retinal microvasculature is a potential biomarker of disease progression in MS.

Macular ganglion cell-inner plexiform layer defect patterns in multiple sclerosis patients without optic neuritis: A Spectral-Domain-Optical Coherence Tomography Cross-Sectional, Case-Control, Pilot Study

PURPOSE

Spectral-domain optical coherence tomography (SD-OCT) was used to evaluate, in patients with multiple sclerosis without a history of optic neuritis (MSNON), the proportion of the different macular ganglion cell-inner plexiform layer complex (mGCIP) defect patterns. The results were compared with those of healthy controls (HCs).

METHODS

In this cross-sectional case-control study, 34 eyes of 34 individuals, 17 with MSNON and 17 HCs, were evaluated. All participants underwent mGCIP thickness measurement using SD-OCT (Zeiss Cirrus HD-OCT 4000, macular cube protocol). The mGCIP defect patterns were classified in nine types (minimal, inner, outer, diffuse mild, diffuse severe inferior confined, inferior dominant, superior confined, and superior dominant), according to the shape derived by the deviation map of the instrument, and the proportion of each type was assessed.

RESULTS

A mGCIP defect pattern was detected in 70.5% of MSNON eyes, with an inner type as the most frequent pattern (47%), followed by the outer type (11.7%) and the inferior confined type (11.7%). No defect was found in Hcs.

CONCLUSIONS

A significant thinning of the mGCIP with the frequent presence of an inner defect was seen in MSNON patients. The presence of this defect may serve as a biomarker of subclinical optic nerve involvement in MS patients.

The Role of Optical Coherence Tomography Angiography in Optic Nerve Head Edema: A Narrative Review

Optic nerve head (ONH) edema is a clinical manifestation of many ocular and systemic disorders. Ocular and central nervous system imaging has been used to differentiate the underlying cause of ONH edema and monitor the disease course. ONH vessel abnormalities are among the earliest signs of impaired axonal transportation. Optical coherence tomography angiography (OCTA) is a noninvasive method for imaging ONH and peripapillary vessels and has been used extensively for studying vascular changes in ONH disorders, including ONH edema. In this narrative review, we describe OCTA findings of the most common causes of ONH edema and its differential diagnoses including ONH drusen.

Association of the retinal vasculature, intrathecal immunity, and disability in multiple sclerosis

BACKGROUND

Optical coherence tomography angiography (OCT-A) is a novel technique allowing non-invasive assessment of the retinal vasculature. During relapsing remitting multiple sclerosis (RRMS), retinal vessel loss occurs in eyes suffering from acute optic neuritis and recent data suggest that retinal vessel loss might also be evident in non-affected eyes. We investigated whether alterations of the retinal vasculature are linked to the intrathecal immunity and whether they allow prognostication of the future disease course.

MATERIAL AND METHODS

This study includes two different patient cohorts recruited at a tertiary German academic multiple sclerosis center between 2018 and 2020 and a cohort of 40 healthy controls. A total of 90 patients with RRMS undergoing lumbar puncture and OCT-A analysis were enrolled into a cross-sectional cohort study to search for associations between the retinal vasculature and the intrathecal immune compartment. We recruited another 86 RRMS patients into a prospective observational cohort study who underwent clinical examination, OCT-A and cerebral magnetic resonance imaging at baseline and during annual follow-up visits to clarify whether alterations of the retinal vessels are linked to RRMS disease activity. Eyes with a history of optic neuritis were excluded from the analysis.

RESULTS

Rarefication of the superficial vascular complex occured during RRMS and was linked to higher frequencies of activated B cells and higher levels of the pro-inflammatory cytokines interferon-γ, tumor necrosis factor α and interleukin-17 in the cerebrospinal fluid. During a median follow-up of 23 (interquartile range 14 - 25) months, vessel loss within the superficial (hazard ratio [HR] 1.6 for a 1%-point decrease in vessel density, p=0.01) and deep vascular complex (HR 1.6 for a 1%-point decrease, p=0.05) was associated with future disability worsening.

DISCUSSION

Optic neuritis independent rarefication of the retinal vasculature might be linked to neuroinflammatory processes during RRMS and might predict a worse disease course. Thus, OCT-A might be a novel biomarker to monitor disease activity and predict future disability.

Correlation analysis between foveal avascular zone and near peripheral retinal hypoperfusion in multiple sclerosis: a wide field optical coherence tomography angiography study

The identification of non-invasive biomarkers to investigate and monitor retinal structural and vascular changes in multiple sclerosis (MS) represents an interesting source of debate. Until now optical coherence tomography angiography (OCTA) evaluated the foveal avascular zone (FAZ) and areas of retinal non-perfusion only in the macular region in MS patients. It could be interesting to identify possible biomarkers, useful in assessing the ischemic areas also in the near peripheral retina, since FAZ enlargement and the areas of peripheral retinal non-perfusions share common pathogenic processes. In this cross-sectional study, we investigated the correlation between the FAZ area and retinal vessel density (VD) in the near peripheral retina by new wide-field optical coherence tomography angiography (OCTA) in patients affected by relapsing-remitting multiple sclerosis (RR-MS). Moreover, we compared the FAZ area and the VD of superficial and deep capillary plexuses in the fovea region and in the near peripheral retina (6.4 × 6.4 mm) between RR-MS patients and healthy controls by means of a Solix full-range OCTA. Last, we also detected the changes in structural OCT parameters (ganglion cell complex and retinal nerve fiber layer). Thirty-three eyes of 33 RR-MS patients and 35 eyes of 35 healthy controls were enrolled. RR-MS patients showed a lower VD in the superficial capillary plexus and a significant increase in the FAZ area compared with controls. The deep capillary plexus revealed a reduced VD although not statistically significant in patients with respect to controls. In the patients' group, the FAZ area showed significantly negative correlations with VD of superficial capillary plexuses in the foveal and whole region, while the FAZ area did not negatively correlate with the VD of the deep capillary plexus. The significant correlations among OCTA parameters could demonstrate the FAZ area as a possible biomarker for assessing the perfusion status in the near peripheral retina, useful in RR-MS management. These findings could confirm the role of vascular dysfunction in the pathogenetic mechanisms of MS.

Microvascular changes in the macular and parafoveal areas of multiple sclerosis patients without optic neuritis

Retinal imaging has been proposed as a biomarker for neurological diseases such as multiple sclerosis (MS). Recently, a technique for non-invasive assessment of the retinal microvasculature called optical coherence tomography angiography (OCTA) was introduced. We investigated retinal microvasculature alterations in participants with relapsing–remitting MS (RRMS) without history of optic neuritis (ON) and compared them to a healthy control group. The study was performed in a prospective, case–control design, including 58 participants (n = 100 eyes) with RRMS without ON and 78 age- and sex-matched control participants (n = 136 eyes). OCTA images of the superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) were obtained using a commercial OCTA system (Zeiss Cirrus HD-5000 Spectral-Domain OCT with AngioPlex OCTA, Carl Zeiss Meditec, Dublin, CA). The outcome variables were perfusion density (PD) and foveal avascular zone (FAZ) features (area and circularity) in both the SCP and DCP, and flow deficit in the CC. MS group had on average higher intraocular pressure (IOP) than controls (P < 0.001). After adjusting for confounders, MS participants showed significantly increased PD in SCP (P = 0.003) and decreased PD in DCP (P < 0.001) as compared to controls. A significant difference was still noted when large vessels (LV) in the SCP were removed from the PD calculation (P = 0.004). Deep FAZ was significantly larger (P = 0.005) and less circular (P < 0.001) in the eyes of MS participants compared to the control ones. Neither LV, PD or FAZ features in the SCP, nor flow deficits in the CC showed any statistically significant differences between the MS group and control group (P > 0.186). Our study indicates that there are microvascular changes in the macular parafoveal retina of RRMS patients without ON, showing increased PD in SCP and decreased PD in DCP. Further studies with a larger cohort of MS patients and MRI correlations are necessary to validate retinal microvascular changes as imaging biomarkers for diagnosis and screening of MS.

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.

Dynamics of Retinal Vessel Loss After Acute Optic Neuritis in Patients With Relapsing Multiple Sclerosis

Background and Objectives

Rarefication of the retinal vasculature as measured by optical coherence tomography angiography (OCT-A) is a novel finding in patients with multiple sclerosis (MS). This study aimed to analyze longitudinal dynamics of the retinal vasculature following an acute inflammatory relapse including acute optic neuritis (ON) and to search for associations with alterations of the retinal architecture and visual function.

Methods

This prospective longitudinal cohort study included patients with relapsing-remitting MS or clinically isolated syndrome having an acute ON (n = 20) or a non-ON relapse (n = 33). Patients underwent examinations at baseline and after 7, 14, 28, 90, and 180 days with OCT, OCT-A, and assessment of the high- (HCVA) and low-contrast visual acuity (LCVA).

Results

Retinal vessel loss of the superficial vascular complex (SVC) evolves early after ON and reaches a plateau between 90 and 180 days (relative vessel loss 15% ± 8% [mean ± SD]). In addition, an 18% ± 18% intraindividual increase of the foveal avascular zone (FAZ) is evident within 180 days after acute ON. Both SVC thinning and FAZ enlargement were associated with worse HCVA and LCVA. Rarefication of the SVC evolved simultaneously to thinning of the common ganglion cell and inner plexiform layer (GCIP) after ON. No alterations of the deep vascular complex were seen in eyes with ON, and no alterations of the retinal vasculature were recognized in patients having acute non-ON relapses.

Discussion

Rarefication of the SVC and growing of the FAZ evolve rapidly after ON and are linked to persistent visual disability. ON-related SVC thinning might be closely linked to GCIP atrophy and might occur due to an altered local metabolic activity within inner retinal layers.

Effect of Vascular Comorbidity on Visual and Disability Outcomes in a Secondary Progressive Multiple Sclerosis Clinical Trial Cohort

Background:

Vascular comorbidity (VC) is associated with multiple sclerosis (MS) disease progression and visual dysfunction. The longitudinal effect of VC in people with secondary progressive MS (SPMS) is unclear. This study explored the impact of VC on standard clinical, MRI, and visual outcomes in people with SPMS enrolled in a clinical trial.

Methods:

Data were extracted from a 2-year randomized controlled trial (N = 51) testing the supplement lipoic acid in people with SPMS who underwent annual Expanded Disability Status Scale, Timed 25-Foot Walk test, MRI, visual acuity testing, and retinal nerve fiber layer (RNFL) and ganglion cell/inner plexiform layer (GCIPL) thicknesses per optical coherence tomography (OCT). Post hoc linear mixed-effects regression analysis compared baseline and annualized outcomes between participants without VC (VC–) and with 1 or more VCs (VC+) (hypertension, dyslipidemia, obesity, diabetes, peripheral or cardiovascular disease, tobacco use).

Results:

The VC– (n = 19) and VC+ (n = 28) participants were similar in age, sex, and MS disease duration and had comparable MS disability, mobility, and brain atrophy at baseline and throughout the 2-year parent study. The VC+ participants had worse baseline visual acuity than those in the VC– group by 0.13 logMAR (P = .041). No significant differences were detected in RNFL or GCIPL baseline thickness or atrophy between groups.

Conclusions:

In an SPMS cohort, VC had an inconsistent effect on standard clinical, MRI, and exploratory OCT outcomes, suggesting that the effect of VC may not be evident in smaller cohort studies. Using a more refined definition of VC in future, adequately powered investigations may help effectively elucidate and account for the interaction between vascular risk burden and MS disability.

Parafoveal and peripapillary vessel density in pediatric and juvenile craniopharyngioma patients

We assessed the retinal microvascular alterations detected by optical coherence tomography angiography (OCT-A) in pediatric and juvenile craniopharyngioma (CP) patients with chiasmal compression. We included 15 eyes of 15 pediatric or juvenile CP patients and 18 eyes of 18 healthy subjects. The evaluation of vessel density from the superficial retinal capillary plexus (SRCP), the deep retinal capillary plexus, and the radial peripapillary capillary (RPC) segments was obtained by OCT-A. The association between vessel density measures and functional and structural measurements was also analyzed. There were significant reductions in the nasal sector of the SRCP (p < 0.0001) and all sectors of the RPC segment vessel density (nasal, temporal, and superior; p < 0.0001, inferior; p = 0.0015) in CP patients postoperatively compared to the healthy subjects. The peripapillary retinal nerve fiber layer (r = 0.6602, p = 0.0074) and ganglion cell-inner plexiform layer thicknesses (r = 0.7532, p = 0.0030) were associated with RPC segment vessel density. Visual acuity (r = − 0.5517, p = 0.0330) and temporal visual field sensitivity loss (r = 0.5394, p = 0.0465) showed an association with SRCP vessel density. In pediatric and juvenile patients with CP, parafoveal and peripapillary vascular changes following chiasmal compression were observed. The changes in vascular structures were closely related to structural and functional outcomes.

Relationship between optical coherence tomography angiography and visual evoked potential in patients with multiple sclerosis

Purpose:

This study aimed to identify an easy-to-apply biomarker by correlating visual evoked potential (VEP) with optical coherence tomography angiography (OCTA) results in multiple sclerosis (MS).

Methods:

Our study was planned prospectively. Patients with MS were divided into two groups, VEP prolonged group 1 and VEP normal group 2. Age-matched and gender-matched healthy individuals (group 3) were included as the control group. Vascular density (VD) of the optic nerve head (ONH) and radial peripapillary capillaries (RPCs) were measured and recorded by OCTA. The optic nerve damage of patients was measured and recorded with a VEP device.

Results:

Thirty-two eyes were included in group 1, 50 eyes were included in group 2, and 51 healthy eyes were included in group 3. In terms of visual acuity, group 1 was significantly lower than the other groups (P < 0.001). Regardless of the prolongation of p100 latency in patients with MS, whole image, inside disc ONH VD and in the same sectors in RPC VD were found to be significantly lower than the control group (P < 0.05). Retinal nerve fiber layer thickness was found to be significantly lower in group 1 than in group 2 and group 3 (P < 0.05). There was a significant correlation between low ONH VD and RPC VD and prolonged VEP P100 (P < 0.05).

Conclusion:

VEP measurements can be correlated with OCTA measurements in patients with MS and can be used as a biomarker to determine the degree of optic nerve damage.

Optical coherence tomography in neurodegenerative disorders

ABSTRACT Structural imaging of the brain is the most widely used diagnostic tool for investigating neurodegenerative diseases. More advanced structural imaging techniques have been applied to early or prodromic phases, but they are expensive and not widely available. Therefore, it is highly desirable to search for noninvasive, easily accessible, low-cost clinical biomarkers suitable for large-scale population screening, in order to focus on making diagnoses at the earliest stages of the disease. In this scenario, imaging studies focusing on the structures of the retina have increasingly been used for evaluating neurodegenerative diseases. The retina shares embryological, histological, biochemical, microvascular and neurotransmitter similarities with the cerebral cortex, thus making it a uniquely promising biomarker for neurodegenerative diseases. Optical coherence tomography is a modern noninvasive imaging technique that provides high-resolution two-dimensional cross-sectional images and quantitative reproducible three-dimensional volumetric measurements of the optic nerve head and retina. This technology is widely used in ophthalmology practice for diagnosing and following up several eye diseases, such as glaucoma, diabetic retinopathy and age-related macular degeneration. Its clinical impact on neurodegenerative diseases has raised enormous interest over recent years, as several clinical studies have demonstrated that these diseases give rise to reduced thickness of the inner retinal nerve fiber layer, mainly composed of retinal ganglion cells and their axons. In this review, we aimed to address the clinical utility of optical coherence tomography for diagnosing and evaluating different neurodegenerative diseases, to show the potential of this noninvasive and easily accessible method.

Retinal and Choriocapillary Vascular Changes in Early Stages of Multiple Sclerosis: A Prospective Study

Optical Coherence Tomography Angiography (OCTA) abnormalities occur in multiple sclerosis (MS) over the course of the disease. OCTA investigations at early MS stages are lacking. We aimed to investigate vessel density in macular and papillary regions over two years after an initial demyelinating event (IDE). Vessel density was analyzed in superficial, deep, choriocapillaris and radial peripapillary plexus at baseline, and after one and two years. We also evaluated structural OCT parameter changes of the ganglion cell complex (GCC) and retinal nerve fiber layer (RNFL). We evaluated 30 eyes from 15 IDE patients (7 females, 8 males, mean age 28.4 ± 9.6 years) and 30 eyes from 15 healthy controls. After 2 years, we reported in the IDE group a reduced vessel density in the superficial capillary plexus, deep capillary plexus and radial peripapillary capillary plexus with respect to the baseline (coeff. β = −2.779, p = 0.013; coeff. β = −4.055, p = 0.018 and coeff. β = −2.687, p ≤ 0.001; respectively), while GCC and RNFL thicknesses did not change. Vessel density reduction was not associated with an expanded disability status scale (EDSS) change, relapse occurrence or magnetic resonance imaging activity. The analysis of healthy controls did not reveal any impairment in OCT and OCTA parameters over 2 years of follow-up. Retinal vascular loss occurs in patients with an IDE independently from clinical and radiological disease activity. Retinal vessel density could represent a novel early biomarker to monitor the MS pathological burden.

Evidence for and against subclinical disease activity and progressive disease in MOG antibody disease and neuromyelitis optica spectrum disorder

Myelin oligodendrocyte glycoprotein antibody disease (MOGAD) and aquaporin-4 IgG seropositive neuromyelitis optica spectrum disorder (AQP4-IgG+ NMOSD) are generally considered to be relapsing disorders, without clinical progression or subclinical disease activity outside of clinical relapses, in contrast to multiple sclerosis (MS). With advances in the diagnosis and treatment of these conditions, prolonged periods of remission without relapses can be achieved, and the question of whether progressive disease courses can occur has re-emerged. In this review, we focus on studies exploring evidence for and against relapse-independent clinical progression and/or subclinical disease activity in patients with MOGAD and AQP4-IgG+ NMOSD.

Retinal microvascular and neuronal function in patients with multiple sclerosis: 2-year follow-up

OBJECTIVE

To determine the longitudinal changes in retinal microstructure, microvasculature, microcirculation, and axonal and neuronal functions in patients with relapsing-remitting multiple sclerosis (RRMS) over the time course of about two years.

METHODS

A total of 30 patients (60 eyes) with RRMS were followed for a period of 27 ± 6 months and evaluated with a battery of clinical tests including low contrast letter acuity (LCLA), intraretinal layer thicknesses by optical coherence tomography (OCT), ganglion cell function by steady-state pattern electroretinography (PERG), axonal function by polarization-sensitive OCT, volumetric vessel density (VVD) by OCT angiography, and retinal tissue perfusion (RTP) by retinal function imager.

RESULTS

Axonal function measured as retinal nerve fiber layer birefringence in the temporal quadrant and vessel density in the deep vascular plexus were significantly decreased at 2-year follow-up (P < 0.05). Subgroup analyses showed that the increased retinal blood flow volume occurred in patients with no evidence of disease activity (NEDA), and with stable or improved visual function (P < 0.05). There was no significant difference in the expanded disability state scale, LCLA, RTP, VVD, or PERG measures between the two visits (P > 0.05).

CONCLUSION

To our best knowledge, this is the first 2-year prospective comprehensive study with a detailed assessment of retinal microstructure and neuronal functions in patients with RRMS. The recovery of retinal microcirculation occurred in patients with NEDA, and stable or improved visual function, suggesting these measurements as potential imaging biomarkers for monitoring disease progression.

Updates on sphingolipids: Spotlight on retinopathy

The sphingolipids ceramide (Cer), ceramide-1-phosphate (C1P), sphingosine (Sph), and sphingosine-1-phosphate (S1P)) are key signaling molecules that regulate many patho-biological processes. During the last decade, they have gained increasing attention since they may participate in important and numerous retinal processes, such as neuronal survival and death, proliferation and migration of neuronal and vascular cells, inflammation, and neovascularization. Cer for instance has emerged as a key mediator of inflammation and death of neuronal and retinal pigment epithelium cells in experimental models of retinopathies such as glaucoma, age-related macular degeneration (AMD), and retinitis pigmentosa. S1P may have opposite biological actions, preventing photoreceptor and ganglion cell degeneration but also promoting inflammation, fibrosis, and neovascularization in AMD, glaucoma, and pro-fibrotic disorders. Alterations in Cer, S1P, and ceramide 1- phosphate may also contribute to uveitis. Furthermore, use of inhibitors that either prevent Cer increase or modulate S1P signaling, such as Myriocin, desipramine, and Fingolimod (FTY720), have been shown to preserve neuronal viability and retinal function. Collectively, the expanding role for these sphingolipids in the modulation of vital processes in retina cell types and in their dysregulation in retinal degenerations makes them attractive therapeutic targets.

The vessel density of the superficial retinal capillary plexus as a new biomarker in cerebral small vessel disease: an optical coherence tomography angiography study

BACKGROUND

Optical coherence tomography angiography (OCTA) is a novel and noninvasive technique for the quantitative assessment of retinal microvascular perfusion. Since the retinal and cerebral small vessels share similar embryological origins, anatomical features, and physiological properties, altered retinal microvasculature might provide a new perspective on the mechanisms of cerebral small vessel disease (CSVD).

OBJECTIVE

We aimed to evaluate retinal vessel density (VD) in patients with CSVD using OCTA and identify associations with cerebral magnetic resonance imaging (MRI) markers and cognitive function.

METHODS

We prospectively recruited 47 CSVD patients and 30 healthy controls (HCs) to participate in the study. All participants underwent OCTA to evaluate retinal microvascular perfusion. The VDs of the macular region in the superficial retinal capillary plexus (SRCP), deep retinal capillary plexus (DRCP), and foveal avascular zone (FAZ) were determined, along with the VD of the optic nerve head (ONH) in the radial peripapillary capillary (RPC) network. Additionally, cerebral MRI and cognitive function tests were performed.

RESULTS

In the macula area, the VD of the CSVD patients was significantly lower than HCs in the temporal quadrant of SRCP. In the ONH area, CSVD patients had lower VD than HCs in the peripapillary RPC network. According to multiple linear regression analysis, decreased VD of the macular SRCP was associated with white matter hyperintensity scores after adjustment for age, hypertension, diabetes, and hyperlipidemia. Furthermore, the VD of the macular SRCP was significantly correlated with CSVD patients' cognitive function, especially global cognition, memory function, attention function, information processing, and executive function.

CONCLUSION

OCTA revealed a significant decrease in retinal microvascular perfusion in CSVD patients, and retinal hypoperfusion was related to MRI markers and cognitive function, suggesting that these parameters could have potential utility as early disease biomarkers.

Disorders of vision in multiple sclerosis

Multiple sclerosis (MS) is a neurological inflammatory disorder known to attack the heavily myelinated regions of the nervous system including the optic nerves, cerebellum, brainstem and spinal cord. This review will discuss the clinical manifestations and investigations for MS and other similar neurological inflammatory disorders affecting vision, as well as the effects of MS treatments on vision. Assessment of visual pathways is critical, considering MS can involve multiple components of the visual pathway, including optic nerves, uvea, retina and occipital cortex. Optical coherence tomography is increasingly being recognised as a highly sensitive tool in detecting subclinical optic nerve changes. Magnetic resonance imaging (MRI) is critical in MS diagnosis and in predicting long-term disability. Optic neuritis in MS involves unilateral vision loss, with characteristic pain on eye movement. The visual loss in neuromyelitis optica spectrum disorder tends to be more severe with preferential altitudinal field loss, chiasmal and tract lesions are also more common. Other differential diagnoses include chronic relapsing inflammatory optic neuropathy and giant cell arteritis. Leber's hereditary optic neuropathy affects young males and visual loss tends to be painless and subacute, typically involving both optic nerves. MS lesions in the vestibulocerebellum, brainstem, thalamus and basal ganglia may lead to abnormalities of gaze, saccades, pursuit and nystagmus which can be identified on eye examination. Medial longitudinal fasciculus lesions can cause another frequent presentation of MS, internuclear ophthalmoplegia, with failure of ipsilateral eye adduction and contralateral eye abduction nystagmus. Treatments for MS include high-dose corticosteroids for acute relapses and disease-modifying medications for relapse prevention. These therapies may also have adverse effects on vision, including central serous retinopathy with corticosteroid therapy and macular oedema with fingolimod.

Optical Coherence Tomography Angiography as a New Tool for Evaluation of the Subclinical Retinal Involvement in Patients with Systemic Lupus Erythematosus-A Review

Knowing the proven relationship between lupus retinopathy and systemic changes and disease activity, it is crucial to find the possibility of early diagnosis of retinal changes at a subclinical level in order to provide faster medical intervention and protect the patient from irreversible changes in the eye and other organs. The aim of this review is an analysis of studies investigating early pathological changes in retinal vascularization obtained by optical coherence tomography angiography (OCTA) and their relationship to the systemic lupus erythematosus (SLE). A literature search was performed to identify all relevant articles, regarding detection of subclinical retinal changes using OCTA in systemic lupus erythematosus listed in PubMed database. Seven out of seven papers found showed a decrease in superficial capillary plexus in ocular asymptomatic patients diagnosed with SLE. A decrease in retinal vessel density measured by OCTA may be a good marker of SLE activity and poor prognosis. OCTA in a safe manner can give clinicians a new perspective on processes of vessel remodeling and answer the question of how SLE might impact the eye from a structural point of view. Adding OCTA to the standard diagnostic process of SLE patients, may detect systemic changes early and prevent further visual deterioration by stopping progression of lupus retinopathy.

Macular vessel density differs in multiple sclerosis and neuromyelitis optica spectrum disorder: An optical coherence tomography angiography study

Multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) are inflammatory and demyelinating diseases that commonly manifest with optic neuritis (ON) but differ in the pathogenic mechanism. Although it was shown that retinal vessels might alter in MS and NMOSD, a comparative study has not been reported. This study evaluated the macular vessel density in 40 MS patients, 13 NMOSD patients, and 20 controls using optical coherence tomography angiography. The vessel density of superficial capillary plexus (SCP) was significantly lower in ON eyes (MS+ON, NMOSD+ON) than in non-ON eyes (MS-ON, NMOSD-ON) and controls. The density of deep capillary plexus (DCP) was significantly increased in MS+ON and MS-ON eyes compared to healthy eyes. In NMOSD+ON and NMOSD-ON, the DCP did not remarkably differ from the control group. A significant positive correlation was noted between SCP and ganglion cell complex (GCC) thickness in MS+ON, MS-ON, and NMOSD+ON. The DCP did not significantly correlate with GCC thickness, but it increased or decreased with ganglion cell loss in MS and NMOSD, respectively. In conclusion, our findings suggest that the capillary changes in MS patients are secondary to ganglion cells' atrophy, while vasculopathy seems to be a primary process in NMOSD patients.

Evaluation of optical coherence tomography angiography findings in patients with multiple sclerosis

Purpose:

To evaluate optical coherence tomography angiography findings in patients with multiple sclerosis (MS).

Methods:

This prospective noninterventional study was conducted on 30 eyes of relapsing-remitting MS patients. Group (1) included 10 eyes with a history of optic neuritis (ON), group (2) included 10 eyes without any history of optic neuritis (MS-ON), and group (3) included 10 eyes of normal age/sex/refraction matched participants. Optical coherence tomography (OCT) and OCT-A (ZEISS Cirrus™ HD-OCT Model 4000 (Carl Zeiss-Meditec, Dublin, CA) of the optic disc were done for all patients.

Results:

The best-corrected visual acuity was diminished in MS cases, especially in patients with ON with P value <0.001. The retinal nerve fiber layer (RNFL) thickness showed a significant decrease in the average thickness and in all quadrants, notably the temporal quadrant in group 1 (P < 0.001). Ganglion cell layer thickness was diminished in average thickness and in all quadrants in both groups of MS, but only the first group showed statistical significance with P value <0.001). In respect to optic disc perfusion, Average, superficial, and deep vascular density index (AVDI, VDI 1, VDI 2) were statistically significantly lower in groups 1, 2 with (P-value < 0.001).

Conclusion:

Decreased vascular perfusion of the optic nerve in MS patients, especially in those with ON is strongly correlated with the damage of RNFL and ganglion cell layer detected by OCT.

Differentiation between multiple sclerosis and neuromyelitis optica spectrum disorder using optical coherence tomography angiography

Neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) are autoimmune demyelinating diseases of distinct etiology presenting with optic neuritis (ON). This study aimed to identify the macular and peripapillary neurovascular alterations that may facilitate the differentiation between NMOSD and MS eyes using spectral-domain optical coherence tomography (OCT) and OCT angiography (OCTA). A total of 13 NMOSD patients and 40 MS patients were evaluated. After ON, the radial peripapillary capillary (RPC) vessel density was significantly decreased in the superior (S) and inferior (I) sectors in NMOSD compared with MS eyes, whereas in non-ON eyes, the temporal (T) sector of RPC was reduced in MS group. In the ON eyes, the retinal nerve fiber layer in the I and T quadrants was thinner in NMOSD than in MS. Regarding ON and non-ON eyes, the macular capillary plexuses, and the ganglion cell complex thickness did not differ between NMOSD and MS. The ratios, based on the disease-specific intra-eye RPC vessel density reduction pattern, were the best discriminants between NMOSD and MS, i.e., inferior to nasal (I/N) and I/T ratios for ON eyes, and S/T and N/T ratios for non-ON eyes. Our results show that the OCTA-based simple ratios may be useful in distinguishing NMOSD and MS patients.

OCT Variability Prevents Their Use as Robust Biomarkers in Multiple Sclerosis

Objective

To evaluate the agreement between the peripapillary retinal nerve fiber layer (pRNFL) and foveal thickness (FT) measurements among three different spectral domain-optical coherence tomography (SD-OCT) instruments in a sample of multiple sclerosis (MS) patients and a healthy age-matched control group.

Methods

An observational cross-sectional study with three groups: healthy subjects and MS patients w/w a previous clinical diagnosis of optic neuritis (ON) was conducted. The pRNFL and FT were measured using three different SD-OCT instruments (OCT PRIMUS 200 and OCT CIRRUS 500 SD-OCT [Carl Zeiss Meditec] and OCT 3D 2000 [Topcon]).

Results

Twenty eyes from 10 healthy subjects matched in age with MS patients without a previous history of eye disease and 62 MS eyes from 31 MS patients (29 eyes without history of ON and 33 eyes with history of ON) were enrolled. Healthy subjects and MS patients without ON did not show differences between the pRNFL and FT thickness (P>0.99) with any of the instruments. However, MS eyes with a previous episode of ON showed thinner pRNFL and FT (P<0.01). PRIMUS and CIRRUS OCT showed better agreement of the pRNLF and FT in both healthy and MS eyes. However, 3D OCT showed less agreement in the pRNFL measurement with CIRRUS in both healthy and MS eyes.

Interpretation

Although OCT is a valuable technology to improve MS patient assessment, differences between devices must be taken into account. It is necessary to create an international group that standardizes the measurement conditions and above all that provides reference bases for normal subjects.

Peripapillary and parafoveal microvascular changes in eyes with optic neuritis and their fellow eyes measured by optical coherence tomography angiography: an Exploratory Study

PURPOSE

This study aimed to evaluate parafoveal and peripapillary microvascular alterations in eyes with optic neuritis (ON) along with their fellow eyes compared to healthy control eyes using optical coherence tomography angiography (OCT-A).

METHODS

We included 31 ON-affected eyes and 31 fellow eyes of 31 patients who had experienced unilateral ON and 33 eyes of 33 healthy controls in this exploratory retrospective cross-sectional study. Optical coherence tomography angiography (OCT-A) was used to generate microvascular structural images and quantify the vessel density of the superficial retinal capillary plexus (SRCP), the deep retinal capillary plexus (DRCP) and radial peripapillary capillary (RPC) segments. We used the Kruskal-Wallis test for the comparison of OCT-A results between the three groups and generalized estimating equation models for the pairwise comparisons.

RESULTS

There were significant differences of SRCP (p = 0.0003) and RPC segment (p < 0.0001) vessel densities between the three groups. Specifically, there was a reduction in parafoveal and peripapillary vessel density in the ON-affected eyes compared to fellow eyes (SRCP, estimates, -1.97, 95% confidence interval [CI], -3.07, -0.87; RPC, -6.95, 95% CI, -8.70, -5.19) and controls (SRCP, -3.15, 95% CI, -4.61, -1.69; RPC, -8.66, 95% CI, -10.55, -6.76). The superior sector of the RPC segments vessel density in the fellow eyes was decreased compared to the controls (-4.93, 95% CI, -8.07, -1.80).

CONCLUSIONS

The results of this study suggest that microvascular changes occur in both the affected eye and unaffected fellow eye after a unilateral ON episode. Future studies are needed to clarify the clinical implications of these findings.

Shortened Pattern Electroretinogram Latency and Impaired Autoregulatory Dynamics to Steady-State Stimuli in Patients With Multiple Sclerosis

BACKGROUND

The steady-state pattern electroretinogram (PERG) is a sensitive measure of retinal ganglion cell (RGC) function that includes within-test progressive changes-adaptation-reflecting RGC autoregulatory dynamics. Comprehensive PERG assessment in patients with multiple sclerosis (MS) (with or without optic neuritis [ON]) may provide unique information about RGC dysfunction and its progression, as well as a comparison between functional loss and structural loss as measured by optical coherence tomography (OCT). The goal of this project was to measure steady-state PERG components and their associations with intraretinal layer thicknesses in MS.

METHODS

One hundred forty eyes of 70 patients with relapsing-remitting MS and 126 eyes of 63 age- and sex-matched healthy control subjects (HC) were investigated using a new-generation PERG method and ultrahigh-resolution OCT. Of MS eyes, there were 30 eyes with ON (MSON), 22 non-ON fellow eyes (MSFE), and 88 non-ON MS eyes (MSNON). PERG amplitude, phase (latency), and adaptation of amplitude and phase were measured and correlated with OCT-determined thicknesses of intraretinal layers.

RESULTS

The average PERG amplitude in MSON eyes was significantly lower than MSFE (P = 0.007), MSNON (P = 0.002), and HC (P < 0.001). The PERG amplitude in MSFE eyes was also significantly lower than HC (P = 0.039). The PERG latency in MSON eyes was significantly shorter than in MSFE (P = 0.001), MSNON (P = 0.002), and HC (P < 0.001). The PERG latency in MSFE (P = 0.007) and MSNON (P = 0.002) was significantly shorter than in HC. However, no significant differences were found between MSFE and MSNON (P > 0.05). PERG adaptation of amplitude in MSON was significantly lower than that in MSNON (P = 0.039) and HC (P = 0.037). Both the amplitude and latency in the MS eyes were significantly correlated with the thicknesses of the macular retinal nerve fiber layer (mRNFL) and ganglion cell-inner plexiform layer (GCIPL).

CONCLUSIONS

Shortened PERG latency and impaired autoregulatory dynamics occurred in MS, suggesting preferential dysfunction of small, slower RGC axons and decreased ability of RGC to autoregulate their gain in response to PERG stimulus. The established relations of PERG measurements with intraretinal thickness measurements suggested that PERG losses were primarily associated with GCIPL and mRNFL thinning.

Advances in ophthalmic structural and functional measures in multiple sclerosis: do the potential ocular biomarkers meet the unmet needs?

PURPOSE OF REVIEW

Multiple sclerosis is a heterogeneous disorder. Biomarkers to monitor disease activities are highly desirable especially because of the recent shift toward personalized medicine that coincides with the expansion of disease-modifying therapy. The visual system is highly involved in multiple sclerosis, and the rapid advancement of ophthalmic techniques has boosted the development of potential ocular biomarkers for multiple sclerosis management.

RECENT FINDINGS

Recent studies have found that the rapid thinning of the peripapillary retinal nerve fiber layer and ganglion cell-inner plexiform layer (GCIPL) occurs in the progressive stage. Furthermore, the inter-eye thickness difference of the GCIPL could be used in identifying unilateral optic neuritis to facilitate the early diagnosis of multiple sclerosis. Moreover, the retinal microvascular alterations measured as vessel density were found to be related to the disability and visual function, although a standardized protocol to measure retinal microvascular alterations has not been well established. Additionally, aberrant ocular motility, such as fixation microsaccades, can be used to measure disability objectively.

SUMMARY

The fast expansion of potential ocular biomarkers measured as retinal microstructural, microvascular, and ocular motility changes may facilitate the diagnosis and management of multiple sclerosis.

Differential patterns of parafoveal and peripapillary vessel density in multiple sclerosis and neuromyelitis optica spectrum disorder

BACKGROUND

To compare intraocular microvascular alterations between patients with multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) using optical coherence tomography angiography (OCT-A).

METHODS

Sixty patients were included in the study, 23 MS patients (36 eyes) and 37 NMOSD patients (47 eyes), all with a history of optic neuritis (ON). All subjects underwent comprehensive ophthalmic examinations, OCT-A, and high-definition-OCT imaging. OCT-A was used to measure the vessel density of the superficial and deep retinal capillary plexus (SRCP and DRCP) in the macular area and the radial peripapillary capillary (RPC) segment. Age, spherical equivalent, and gender were adjusted for in the analyses.

RESULTS

Patients with NMOSD showed significantly decreased vessel density of the SRCP (average, p = 0.0007; superior, p = 0.0009; inferior, p = 0.0002) and RPC segment (average, p < 0.0001; superior, p = 0.0004; inferior, p = 0.0052; temporal, p < 0.0001; nasal, p = 0.0001) compared to the MS patients. Parafoveal and peripapillary vessel density was significantly associated with the OCT parameters in both the MS and NMOSD patients. Parafoveal and peripapillary vessel density in the MS patients was significantly associated with visual function, including visual acuity and visual field defects, whereas only peripapillary vessel density was significantly associated with visual function in the NMOSD patients.

CONCLUSION

We demonstrated parafoveal and peripapillary vascular alterations between MS and NMOSD patients that varied in degree and pattern. We also found associations between vessel density and structural and functional parameters in MS and NMOSD patients. Further studies are needed to facilitate a greater understanding of the pathogenesis and its association with vascular alterations in these disorders.

The role of optical coherence tomography in the diagnosis of afferent visual pathway problems: A neuroophthalmic perspective

Optical coherence tomography (OCT) is a noninvasive ocular imaging technique that has become a standard tool in neuroophthalmic practice. Specifically, OCT captures retinal manifestations of neuroaxonal injury caused by lesions along anterior and posterior regions of the afferent visual pathway, in patients presenting with vision loss. More recently, the advent of OCT angiography (OCTA) has enabled evaluation of the choroidal and retinal microvasculature, thus informing our understanding regarding vascular mechanisms associated with optic nerve and retinal injuries. Much of our longitudinal experience with OCT in the field of neuroophthalmology has been acquired from the study of optic neuritis (ON) caused by inflammatory disorders of the central nervous system (CNS). Over the past two decades, OCT has emerged as a surrogate endpoint for CNS neuroaxonal injury in multiple sclerosis (MS) research trials. On a more pragmatic level, OCT is used in the clinical arena to diagnose ON associated with: MS, neuromyelitis optica spectrum disorder (NMOSD), and myelin oligodendrocyte glycoprotein (MOG) antibody associated disease (MOGAD). Subsequent advancements in swept-source (SS) and enhanced depth imaging (EDI) have established OCT as the new "gold standard" in the diagnosis of optic disc drusen. Recent studies have highlighted pathognomonic OCT features that distinguish cases of true papilledema from pseudopapilledema, in patients presenting with undifferentiated optic disc elevation. Preoperative OCT measures of neuroaxonal integrity have shown prognostic value in predicting postoperative visual outcomes for patients with compressive anterior visual pathway lesions. Finally, OCT is indispensable in differentiating optic neuropathies from retinal diseases in patients with visual loss and a nondiagnostic fundus examination. An in-depth discussion regarding the technical aspects of OCT is beyond the scope of this chapter. Instead, we wish to highlight the value OCT brings to the diagnosis and management of common neuroophthalmic conditions, with emphasis on optic neuropathies and retinal disorders.