Retinal segmented layers with strong aquaporin-4 expression suffered more injuries in neuromyelitis optica spectrum disorders compared with optic neuritis with aquaporin-4 antibody seronegativity detected by optical coherence tomography

Sample size estimation for AQP4-IgG seropositive optic neuritis: Retinal damage detection by optical coherence tomography

We recruited four aquaporin-4 seropositive optic neuritis patients (five eyes) who received glucocorticoid treatment and underwent optical coherence tomography examination. Baseline medians of the macular ganglion cell layer plus inner plexiform layer (mGCIPL) thickness and volume for the eye of interest were 79.67 µm (73.664 ± 18.497 µm) and 0.58 mm3 (0.534 ± 0.134 mm3), respectively. At 2 months, the medians of the mGCIPL thickness and volume were 60.00 µm (51.576 ± 12.611 µm) and 0.44 mm3 (0.376 ± 0.091 mm3), respectively. At 6 months, the medians of the mGCIPL thickness and volume were 59.55 µm (46.288 ± 11.876 µm) and 0.44 mm3 (0.336 ± 0.084 mm3), respectively. Sample size estimate was achieved using two methods based on the mGCIPL thickness and volume data, with five effect sizes considered. The estimate based on the mGCIPL volume showed that 206 patients were needed at the 6-month follow-up; the power was 80% and effect size was 20%. In conclusion, this study detected retinal damage in aquaporin-4 seropositive optic neuritis patients by optical coherence tomography, and estimated the sample size for two-sample parallel designed clinical trials using two methods.

A comparative study of alteration in retinal layer segmentation alteration by SD-OCT in neuromyelitis optica spectrum disorders: A systematic review and meta-analysis

Background

To evaluate the feature of different retinal layer segmentation in neuromyelitis optica spectrum disorders (NMOSD) with spectral-domain optical coherence tomography (SD-OCT) and to compare it with that in multiple sclerosis (MS), healthy controls (HC), and idiopathic optic neuritis (ION).

Methods

We retrieved four electronic databases, including Pubmed, Embase, Cochrane Library, and Web of Science from inception to September 1st, 2021. A meta-analysis was performed to compare different retinal layer segmentation thicknesses between patients with or without a history of optic neuritis (ON) in NMOSD and the control group, including patients with MS, HC, and ION.

Results

Forty-two studies were included and the interval between the last ON onset and examination was greater than 3 months. Compared with that in HC eyes, the loss of retinal nerve fiber layer (RNFL) and macular ganglion cell and inner plexiform layer (GC-IPL) was serious in NMOSD eye especially after ON. Moreover, compared with that in ION eyes or MS-related-ON eyes, the injury to the peripapillary retinal nerve fiber layer (pRNFL) was severe in NMOSD-related-ON eyes. In addition, the correlation coefficient between pRNFL and prognostic visual acuity was 0.43. However, the one-arm study revealed the inner nuclear layer (INL) was thickened in NMOSD-related-ON eyes compared with HC eyes.

Conclusions

Inclusion of the RNFL and macular GC-IPL is recommended for monitoring disease progression and attention should be paid to changes in the INL.

Different alteration patterns of sub-macular choroidal thicknesses in aquaporin-4 immunoglobulin G antibodies sero-positive neuromyelitis optica spectrum diseases and isolated optic neuritis

PURPOSE

The ocular choroid is a sensitive biomarker of vascular perfusion in optic neuritis (ON) patients due to its vascular structures. The purpose of this study was to evaluate alterations in sub-macular choroidal thicknesses (sub-MCT) in aquaporin-4 immunoglobulin G antibodies (AQP4-IgG) sero-positive neuromyelitis optica spectrum disease (AQP4-IgG+/NMOSD) and isolated ON (ION) patients using optical coherence tomography (OCT).

METHODS

A total of 208 ON patients (275 eyes) and healthy controls (HCs) who underwent sub-MCT and retinal microstructure detection with OCT were enrolled in this study.

RESULTS

Among all the ON patients, 102 (49.0%) cases were identified as serum AQP4-IgG-positive, with 106 (51.0%) cases being negative, excluding multiple sclerosis as the ION cohort. The sub-MCT in the AQP4-IgG+/NMOSD patients decreased in 0-6 months after ON attacks. However, for the ION cohort, the sub-MCT decreased in 0-2 months and then stayed normal or slightly increased in 2-4 months after the first ON attack, finally sharply decreasing after 6 months. For unilateral AQP4-IgG+/NMOSD patients, eyes without ON also presented retinal layer thinning and sub-MCT slight reduction independent of ON attacks.

CONCLUSIONS

The sub-MCT in AQP4-IgG+/NMOSD patients were reduced at all stages of ON, which distinguished the ION patients as decreasing only at chronic stage of ON. It implied that ocular vascular hypoperfusion plays a potential role in ON pathogenesis and the different patterns could be caused by the distinct pathogenesis of AQP4-IgG+/NMOSD and ION.

Optical Coherence Tomography in Neuromyelitis Optica spectrum disorder and Multiple Sclerosis: A population-based study

BACKGROUND

The aim of this study was to identify and compare the characteristics of retinal nerve layers using spectral domain-optical coherence tomography (SD-OCT) in neuromyelitis optica spectrum disorder (NMOSD), relapsing-remitting multiple sclerosis (RRMS) and healthy controls (HCs).

METHODS

It is a cross-sectional population-based study in Isfahan, Iran. We enrolled 98 participants including 45 NMOSD patients (90 eyes), 35 RRMS patients (70 eyes) and 18 HCs (36 eyes). Evaluation criteria were thickness of different sectors in peripapillary retinal nerve fiber layer (pRNFL) and intra-retinal layers around the macula. History of previous optic neuritis (ON) was obtained through chart review and medical record.

RESULTS

Without considering ON, total macular, ganglion cell layer (GCL) and pRNFL were significantly thinner in both groups of patients compared to HCs. On macular examination, GCL and total macular thickness were significantly thinner than HCs in all NMOSD and RRMS eyes with and without history of ON. While there was no significant difference between MS-ON and MS without a history of ON in the macular measures, the reduction in total macular and GCL thickness was significantly greater in NMOSD-ON compared to NMOSD without a history of ON. Also in NMOSD-ON eyes, the RNFL, GCL, IPL and GCIPL layers were significantly thinner than that of MS-ON. On the other hand, the pRNFL study showed significant thinning of all quadrants in the RRMS and NMOSD groups relative to HCs. While the decrease of pRNFL thickness in the eyes of NMOSD-ON and MS with and without a previous history of ON was significantly greater than that of HCs, no difference was observed between NMOSD without ON and HCs. In addition, in NMOSD patients, pRNFL was significantly thinner in eyes with history of ON compared to non ON-eyes. Furthermore, in patients with a history of ON, reduction in all sectors of pRNFl (except in T) was significantly greater in NMOSD compared to MS patients.

CONCLUSION

Our findings showed that although macular and retinal damage occurred in both NMOSD and RRMS patients without significant differences, the severity of injury in eyes with history of ON was significantly higher in NMOSD compared to MS patients, that could be considered as a marker to distinguish them. In addition, our results confirmed the absence of subclinical optic nerve involvement in NMOSD unlike MS patients.

AQP4-IgG and MOG-IgG Related Optic Neuritis-Prevalence, Optical Coherence Tomography Findings, and Visual Outcomes: A Systematic Review and Meta-Analysis

Background: Optic neuritis (ON) is a cardinal manifestation of multiple sclerosis (MS), aquaporin-4 (AQP4)-IgG-, and myelin oligodendrocyte glycoprotein (MOG)-IgG-associated disease. However, the prevalence of AQP4-IgG seropositivity and MOG-IgG seropositivity in isolated ON is unclear, and studies comparing visual outcomes and optical coherence tomography (OCT)-derived structural retinal measures between MS-ON, AQP4-ON, and MOG-ON eyes are limited by small sample sizes. Objectives: (1) To assess the prevalence of AQP4-IgG and MOG-IgG seropositivity among patients presenting with isolated ON; (2) to compare visual outcomes and OCT measures between AQP4-ON, MOG-ON, and MS-ON eyes. Methods: In this systematic review and meta-analysis, a total of 65 eligible studies were identified by PubMed search. Statistical analyses were performed with random effects models. Results: In adults with isolated ON, AQP4-IgG seroprevalence was 4% in non-Asian and 27% in Asian populations, whereas MOG-IgG seroprevalence was 8 and 20%, respectively. In children, AQP4-IgG seroprevalence was 0.4% in non-Asian and 15% in Asian populations, whereas MOG-IgG seroprevalence was 47 and 31%, respectively. AQP4-ON eyes had lower peri-papillary retinal nerve fiber layer (pRNFL; -11.7 μm, 95% CI: -15.2 to -8.3 μm) and macular ganglion cell + inner plexiform layer (GCIPL; -9.0 μm, 95% CI: -12.5 to -5.4 μm) thicknesses compared with MS-ON eyes. Similarly, pRNFL (-11.2 μm, 95% CI: -21.5 to -0.9 μm) and GCIPL (-6.1 μm, 95% CI: -10.8 to -1.3 μm) thicknesses were lower in MOG-ON compared to MS-ON eyes, but did not differ between AQP4-ON and MOG-ON eyes (pRNFL: -1.9 μm, 95% CI: -9.1 to 5.4 μm; GCIPL: -2.6 μm, 95% CI: -8.9 to 3.8 μm). Visual outcomes were worse in AQP4-ON compared to both MOG-ON (mean logMAR difference: 0.60, 95% CI: 0.39 to 0.81) and MS-ON eyes (mean logMAR difference: 0.68, 95% CI: 0.40 to 0.96) but were similar in MOG-ON and MS-ON eyes (mean logMAR difference: 0.04, 95% CI: -0.05 to 0.14). Conclusions: AQP4-IgG- and MOG-IgG-associated disease are important diagnostic considerations in adults presenting with isolated ON, especially in Asian populations. Furthermore, MOG-IgG seroprevalence is especially high in pediatric isolated ON, in both non-Asian and Asian populations. Despite a similar severity of GCIPL and pRNFL thinning in AQP4-ON and MOG-ON, AQP4-ON is associated with markedly worse visual outcomes.

Retinal Degeneration After First-Ever Optic Neuritis Helps Differentiate Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder

Objective: Differentiation between neuromyelitis optica spectrum disorder (NMOSD) and multiple sclerosis (MS) in the early phase is challenging but crucial for treatment and prognosis.

Methods: We performed a prospective cross-sectional study to discriminate NMOSD from MS by evaluating retinal degeneration in optical coherence tomography (OCT) after a first-ever optic neuritis (ON) episode. Seventy-three NMOSD patients and 38 MS patients with ON at least 3 months prior were assessed by OCT, best-corrected visual acuity (VA), and 2.5% low-contrast VA. Multivariate linear regression models were used for comparisons. Receiver operating characteristic curves and Youden index were used for determining the discriminative value of retinal nerve fiber layer thickness (RNFL) and VA in distinguishing NMOSD from MS.

Results: Among eyes with retinal degeneration after a first-ever ON episode (n = 93), NMOSD eyes (n = 60) presented thinner RNFL (p < 0.001) and worsened VA (p < 0.001) relative to MS eyes (n = 33). Furthermore, a RNFL thinner than 78.9 μm had a specificity of 93.9% for NMOSD; combined with a VA of <0.4 decimal, these characteristics provided 100% specificity for NMOSD.

Conclusions: The first-ever ON eyes showed more severe retina degeneration in patients with NMOSD than MS, which could establish a cut-off of RNFL thickness and VA to distinguish NMOSD from MS in the early phase.

Different Characteristics of Aquaporin-4 and Myelin Oligodendrocyte Glycoprotein Antibody-Seropositive Male Optic Neuritis in China

Purpose

To describe different clinical characteristics and prognosis of optic neuritis (ON) in male patients with seropositive aquaporin-4 antibody (AQP4-Ab) or myelin oligodendrocyte glycoprotein antibody (MOG-Ab) in China.

Method

Males with ON were recruited from the Neuro-ophthalmology Department of the Chinese People's Liberation Army, General Hospital from January 2016 to February 2018. They were assigned to two groups based on antibodies status: MOG-Ab-seropositive ON (MOG-ON) and aquaporin-4 Ab-seropositive ON (AQP4-ON).

Results

Seventy-six male patients were assessed, including 44 MOG-ON (57.9%) and 32 AQP4-ON (42.1%). The MOG-ON patients were significantly younger at onset compared to the AQP4-ON group (p < 0.001). Frequencies of optic disc swelling, presence of abnormal autoimmune antibodies, and elevated levels of CSF IgG were significantly higher in the AQP4-ON group than the MOG-ON group (p=0.040, p=0.016, and p=0.10, respectively). At the final visit, 85.3% of MOG-ON eyes had increased visual acuity (≥0.5) compared to 35.1% of AQP4-ON eyes (p < 0.001). The ratio of this steroid-dependent condition is higher in MOG-ON patients than the AQP4-ON group (p < 0.001). The ratio of conversion to NMO is higher in the AQP4-ON group than the MOG-ON group, with more AQP4-ON patients developing NMO by the follow-up (p=0.012). MOG-ON patients had thicker average peripapillary retinal nerve fiber layers and macular ganglion cell-inner plexiform than AQP4-ON patients (p=0.008 and p=0.012, respectively). Orbital MRI revealed more AQP4-ON patients had chiasmal involvement than MOG-ON patients (p < 0.001).

Conclusion

Male MOG-ON patients had different clinical features including earlier age of onset, higher optic disc swelling ratio, better visual acuity recovery, thicker peripapillary retinal nerve fiber and macular ganglion cell-inner plexiform layers, and less chiasmal involvement than male AQP4-ON patients. Serum antibody may be a potential biomarker for determining visual prognosis in male ON.

Altered Macular Microvasculature in Neuromyelitis Optica Spectrum Disorders

PURPOSE

To evaluate macular microvascular changes in neuromyelitis optica spectrum disorders (NMOSD) by using optical coherence tomography angiography (OCT-A) and investigate their correlations with neuroaxonal structural damage evaluated with spectral-domain OCT (SD-OCT).

DESIGN

Cross-sectional study.

METHODS

Twenty eyes of 20 patients with NMOSD and 21 eyes from 21 healthy controls were enrolled. OCT-A was used to obtain microvascular network images of the whole, superficial, and deep retinal capillary plexuses (WRCP, SRCP, and DRCP) in a 3-mm-diameter area around the macula. SD-OCT was used to obtain the intraretinal thickness. Custom automated algorithms quantified the thickness of the intraretinal layers as well as microvascular density of the retinal capillary layers.

RESULTS

NMOSD patients showed significantly decreased microvascular density in both SRCP and DRCP (P < .05) compared to controls. The decreased microvascular density in SRCP and DRCP significantly correlated with the frequency of optic neuritis attack (P < .05). Both SRCP and DRCP microvascular density significantly correlated (P < .05) with retinal nerve fiber layer and ganglion cell layer with inner plexiform layer. SRCP microvascular density moderately correlated with visual acuity, while a stronger correlation was found between DRCP and visual acuity.

CONCLUSIONS

Decreased microvascular density in NMOSD patients correlated with the worsening of their visual acuity. Correlation between microvascular impairment and neuroaxonal thinning revealed that retinal microvascular alteration may contribute to neuroaxonal loss in NMOSD patients. OCT-A with measurable analysis offers a new path of study and will likely be useful as an objective biomarker for detecting microvascular impairment in NMOSD.

Clinical features of demyelinating optic neuritis with seropositive myelin oligodendrocyte glycoprotein antibody in Chinese patients

BACKGROUND/AIMS

To investigate the clinical features of Chinese patients with seropositive myelin oligodendrocyte glycoprotein antibody (MOG-Ab) optic neuritis (ON) and patients with seropositive aquaporin-4 antibody (AQP4-Ab) ON.

METHODS

In this retrospective observational study, sera from patients with demyelinating ON were tested for MOG-Ab and AQP4-Ab with a cell-based assay. Clinical characteristics were compared between MOG-Ab-related ON (MOG-ON) and AQP4-Ab-related ON (AQP4-ON), including visual performances, serum autoantibodies and features on MRI.

RESULTS

A total of 109 affected eyes from 65 patients with demyelinating ON (20 MOG-ON and 45 AQP4-ON) were included. The onset age of MOG-ON was younger than AQP4-ON (MOG-ON: 20.2±17.4 years old, AQP4-ON: 35.6±15.7 years old, P=0.001). Onset severity was not different between these two groups (P=0.112), but patients with MOG-ON showed better visual outcomes (P=0.004). Half of the MOG-ON had a relapsing disease course. Nineteen per cent of patients with AQP4-ON presented coexisting autoimmune disorders, but there were no coexisting autoimmune disorders among patients with MOG-ON. Optic nerve head swelling was more prevalent in patients with MOG-ON (P<0.01). Retrobulbar segment involvement of the optic nerve were more common in patients with MOG-ON according to our MRI findings (P<0.01). Patients with MOG-ON showed longitudinally extensive lesion in 30% and chiasm and optic tract involvement in 5%.

CONCLUSIONS

MOG-ON is not rare in Chinese demyelinating patients. It underwent a severe vision loss at onset but had relatively better visual recovery than patients with AQP4-ON. MOG-ON might have an unique pathogenesis different from AQP4-ON.