Comparison of Early- and Late-Onset NMOSD-Related Optic Neuritis in Thai Patients: Clinical Characteristics and Long-Term Visual Outcomes

Figures & data

Figure 1 Flow chart of the study selection based on the inclusion and exclusion criteria.

Table 1 Comparison of Demographic Characteristics in Patients with LO-NMOSD-ON and Patients with EO-NMOSD-ON

Demographic Data	LO-NMOSD-ON	EO-NMOSD-ON	p-value
▫ Number of patients, n	14	33
▫ Number of affected eyes, n	21	48
▫ Female: male ratio (% of patients who were female)	13:1 (92.8%)	33:0 (100%)	0.29
▫ Age at ON onset, mean ± standard deviation, years	64.1 ± 12.3	32.6 ± 9.3	< 0.001*
▫ ON follow-up interval, median (range), months	59.5 (6–144)	43 (6–228)	0.93
▫ Non-ON demyelinating events prior to or concurrent with ON onset, n of patients/n of patients with available data (%)	2/10 (20.0%)	7/22 (31.8%)	0.68
Myelitis, n of patients/n of patients with non-ON demyelinating events prior to or concurrent with ON onset (%)	2/2 (100%)	7/7 (100%)	0.69
Area postrema syndrome, n of patients/n of patients with non-ON demyelinating events prior to or concurrent with ON onset (%)	0/2 (0%)	0/7 (0%)	-
Acute brainstem syndrome, n of patients/n of patients with non-ON demyelinating events prior to or concurrent with ON onset (%)	0/2 (0%)	3/7 (42.8%)^†	0.53
Symptomatic cerebral syndrome, n of patients/n of patients with non-ON demyelinating events prior to or concurrent with ON onset (%)	0/2 (0%)	0/7 (0%)	-
▫ Presence of antinuclear antibody, n of patients/n of patients with available data (%)	7/14 (50.0%)	19/33 (57.5%)	0.63
▫ Concurrent autoimmune diseases, n of patients (%)	2/14 (14.2%)	9/33 (27.2%)	0.46
Sjogren syndrome, n of patients/n of patients with concurrent autoimmune diseases (%)	0/2 (0%)	3/9 (33.3%)	0.54
Systemic lupus erythematosus, n of patients/n of patients with concurrent autoimmune diseases (%)	1/2 (50.0%)	4/9 (44.4%)	0.54
Graves’ disease, n of patients/n of patients with concurrent autoimmune diseases (%)	1/2 (50.0%)	1/9 (11.1%)	0.51
Myasthenia gravis, n of patients/n of patients with concurrent autoimmune diseases (%)	0/2 (0%)	1/9 (11.1%)	1.00

Notes: * Statistically significant (p < 0.05); ^†These three patients were also included in the seven patients who had myelitis prior to or concurrent with ON onset, due to the presence of both myelitis and acute brainstem syndrome prior to or concurrent with ON onset.

Abbreviations: LO-NMOSD-ON, late-onset neuromyelitis optica spectrum disorder-related optic neuritis; EO-NMOSD-ON, early-onset neuromyelitis optica spectrum disorder-related optic neuritis; ON, optic neuritis; n, number.

Table 2 Clinical Characteristics at ON Onset in Patients with LO-NMOSD-ON and Patients with EO-NMOSD-ON

Clinical Characteristics at ON Onset	LO-NMOSD-ON	EO-NMOSD-ON	p-value
▫ Bilaterality, n of patients/n of patients with available data (%)	0/10 (0%)	2/22 (9.1%)	1.00
▫ Presence of pain, n of eyes/n of eyes with available data (%)	6/10 (60.0%)	19/24 (79.1%)	0.39
▫ Nadir VA at ON onset
Nadir VA at ON onset, median (range), logMAR	2.7 (2.6–2.9)	1.95 (0.4–2.9)	0.03*
Nadir VA at ON onset worse than or equal to 1.0 logMAR, n of eyes/n of eyes with available data (%)	10/10 (100%)	15/24 (62.5%)	0.03*
▫ Presence of optic disc edema, n of eyes/n of eyes with available data (%)	0/10 (0.0%)	8/24 (33.3%)	0.07

Note: *Statistically significant (p < 0.05).

Abbreviations: LO-NMOSD-ON, late-onset neuromyelitis optica spectrum disorder-related optic neuritis; EO-NMOSD-ON, early-onset neuromyelitis optica spectrum disorder-related optic neuritis; ON, optic neuritis; VA, visual acuity; logMAR, logarithm of the minimum angle of resolution; n, number.

Table 3 Magnetic Resonance Imaging Characteristics at ON Onset in Patients with LO-NMOSD-ON and Patients with EO-NMOSD-ON: Segmental Enhancement of AVPs

Segmental Enhancement of AVPs	LO-NMOSD-ON (n = 10 AVPs)	EO-NMOSD-ON (n = 24 AVPs)	p-value
▫ Segmental enhancement of AVPs, n of AVPs with each enhanced segment/n of available AVPs (%)
Orbital optic nerve	8/10 (80.0%)	17/24 (70.8%)	0.69
Intracanalicular optic nerve	6/10 (60.0%)	19/24 (79.1%)	0.39
Intracranial optic nerve	2/10 (20.0%)	13/24 (54.1%)	0.12
Optic chiasm	0/10 (0.0%)	4/24 (16.6%)	0.29
Optic tract	0/10 (0.0%)	1/24 (4.1%)	1.00 0.43
≥2 consecutive enhanced segments	6/10 (60.0%)	18/24 (75.0%)
▫ Total enhanced segments, mean ± standard deviation, segments	1.60 ± 0.51	2.20 ± 1.02	0.08

Abbreviations: LO-NMOSD-ON, late-onset neuromyelitis optica spectrum disorder-related optic neuritis; EO-NMOSD-ON, early-onset neuromyelitis optica spectrum disorder-related optic neuritis; ON, optic neuritis; AVP, anterior visual pathway; n, number.

Table 4 Acute-Phase Treatment in Patients with LO-NMOSD-ON and Patients with EO-NMOSD-ON

Acute-Phase Treatment	LO-NMOSD-ON	EO-NMOSD-ON	p-value
▫ Number of ON episodes treated in our institution, n	24	63	-
▫ Interval from ON onset to intravenous methylprednisolone treatment, median (range), days	5 (1–45)	6 (0–45)	0.62
▫ Adjunctive plasma exchange, n of episodes (%)	2 (8.3%)	5 (7.9%)	1.00

Abbreviations: LO-NMOSD-ON, late-onset neuromyelitis optica spectrum disorder-related optic neuritis; EO-NMOSD-ON, early-onset neuromyelitis optica spectrum disorder-related optic neuritis; ON, optic neuritis; n, number.

Table 5 Maintenance-Phase Treatment in Patients with LO-NMOSD-ON and Patients with EO-NMOSD-ON: Immunosuppressive Drugs Used at the Last Follow-Up

Maintenance-Phase Treatment	LO-NMOSD-ON	EO-NMOSD-ON	p-value
▫ Immunosuppressive drugs used at the last follow- up, n of patients (%)	8 (57.1%)	27 (81.8%)	0.14
Azathioprine	4/8 (50%)	10/27 (37.0%)	1.00
Rituximab	1/8 (12.5%)	2/27 (7.4%)	1.00
Mycophenolate mofetil	3/8 (37.5%)	12/27 (44.4%)	0.49
Intravenous cyclophosphamide	0/8 (0.0%)	2/27 (7.4%)	1.00
Methotrexate	0/8 (0.0%)	1/27 (3.7%)	1.00

Note: Unless otherwise indicated, data are shown as n of patients receiving each immunosuppressive drug/total n of patients receiving immunosuppressive drugs (%).

Abbreviations: LO-NMOSD-ON, late-onset neuromyelitis optica spectrum disorder-related optic neuritis; EO-NMOSD-ON, early-onset neuromyelitis optica spectrum disorder-related optic neuritis; n, number.

Table 6 Long-Term Visual Outcomes in Patients with LO-NMOSD-ON and Patients with EO-NMOSD-ON

Long-Term Visual Outcomes	LO-NMOSD-ON	EO-NMOSD-ON	p-value	Adjusted p-value
▫ Final VA
Final VA, median (range), logMAR	1.3 (0–2.9)	0.3 (0–2.9)	0.01*	0.037*
Final VA worse than or equal to 1.0 logMAR, n of eyes/n of eyes with available data (%)	12/21 (57.1%)	13/48 (27.0%)	0.03*	0.039*
▫ ON relapse, n of patients (%)	7 (50.0%)	19 (57.5%)	0.63	-
▫ ON annualized relapse rate, median (range)	0.25 (0.16–0.41)	0.31 (0.13–1.40)	0.30	-
▫ Interval from ON onset to first ON relapse, median (range), months	48 (24–72)	20.5 (2–90)	0.20	-
▫ Deaths, n of patients (%)	2 (14.2%)	0 (0.0%)	0.29	-

Note: *Statistically significant (p < 0.05).

Abbreviations: LO-NMOSD-ON, late-onset neuromyelitis optica spectrum disorder-related optic neuritis; EO-NMOSD-ON, early-onset neuromyelitis optica spectrum disorder-related optic neuritis; ON, optic neuritis; VA, visual acuity; logMAR, logarithm of the minimum angle of resolution; n, number.

Figure 2 Correlation analysis revealed a positive correlation between age at ON onset of each eye (years) and final VA (logMAR) (Spearman r = 0.34, p = 0.0075) in patients with LO-NMOSD-ON and patients with EO-NMOSD-ON.