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

Area of Science:

• Neuro-ophthalmology
• Neuroimmunology
• Medical imaging

Background:

• Neuromyelitis optica spectrum disorder (NMOSD) and relapsing-remitting multiple sclerosis (RRMS) are inflammatory demyelinating diseases affecting the central nervous system.
• Retinal nerve layer damage, detectable by spectral domain-optical coherence tomography (SD-OCT), is a known feature in both conditions.

Purpose of the Study:

• To compare retinal nerve layer characteristics in NMOSD, RRMS, and healthy controls (HCs) using SD-OCT.
• To investigate the impact of optic neuritis (ON) history on retinal damage in NMOSD and RRMS patients.

Main Methods:

• A cross-sectional study involving 98 participants (45 NMOSD, 35 RRMS, 18 HCs).
• SD-OCT was used to measure peripapillary retinal nerve fiber layer (pRNFL) and macular retinal layers (ganglion cell layer [GCL], inner plexiform layer [IPL], and ganglion cell-inner plexiform layer [GCIPL]).
• Optic neuritis history was obtained via medical records.

Main Results:

• Both NMOSD and RRMS patients exhibited thinner macular GCL, total macular thickness, and pRNFL compared to HCs, irrespective of ON history.
• Eyes with a history of ON showed significantly greater thinning in macular and pRNFL measures in NMOSD compared to RRMS.
• NMOSD eyes with ON had thinner RNFL, GCL, IPL, and GCIPL compared to RRMS eyes with ON.

Conclusions:

• Macular and retinal damage are present in both NMOSD and RRMS, with similar severity in the absence of ON history.
• The greater severity of retinal damage in NMOSD eyes with ON history compared to RRMS eyes with ON history may serve as a distinguishing marker.
• Subclinical optic nerve involvement appears absent in NMOSD, unlike in MS patients.