Choroidal structure differs between multiple sclerosis and neuromyelitis optica spectrum disorder: An enhanced depth...

To investigate the difference in choroidal structure between multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD) patients with or without optic neuritis (ON) attacks using enhanced depth imaging optical coherence tomography (EDI-OCT).

This prospective case-control study included 30 eyes of MS, 32 eyes of NMOSD, and the same number of eyes from healthy controls. All participants underwent EDI-OCT examination. The choroidal thickness (CT) was evaluated at the subfoveal and eight sites around the subfoveal. Total choroidal area (TCA), luminal area (LA), stromal area (SA), and choroidal vascularity index (CVI) were calculated by binarizing EDI-OCT images.

There were 6 and 12 eyes with histories of ON in MS and NMOSD patients, respectively. Compared with MS patients, NMOSD patients had significantly thinner CTs at most sites and smaller TCA and LA regardless of ON attacks (p< 0.05). There was no significant difference in the CVI between MS and NMOSD patients with ON (p= 0.723) or without ON (p= 0.383). Among patients with ON attacks, compared with healthy controls, MS patients showed a trend toward larger choroidal parameters, whereas NMOSD patients exhibited a trend toward smaller values, although these differences were not statistically significant (all p > 0.05).

NMOSD patients exhibited a trend toward reduced ocular vascular perfusion compared to MS patients, irrespective of ON attack history. However, the lack of statistical significance compared with healthy controls suggests that these differences may be largely attributable to baseline imbalances, such as age. Further studies are warranted to verify the trend of the difference.