A new study published in the journal Scientific Reports has helped explain the differences between neuromyelitis optics spectrum disorder (NMOSD) after optic neuritis (ON) and multiple sclerosis (MS). Although previous studies have had the same aim, this study specifically also included non-optic neuritis eyes.

This investigation was completed using optical coherence tomography angiography or OCTA.

The Study

MS and NMOSD are both autoimmune conditions. Both can cause optic neuritis.

Previous research has investigated the eyes of those who have faced ON using spectral-domain OCT technology. These investigations have measured ganglion cell complex (GCC) as well as the thickness of the retinal nerve fiber layer (RNFL). These measures allowed researchers to tell the difference between ON patients with MS and NMOSD. Those who experienced larger reductions in RNFL thickness and GCC had NMOSD.

This new study also measured the eyes of those who didn’t have ON.

There were a total of 13 patients diagnosed with NMOSD as well as 40 diagnosed with MS. Every MS patient was currently being treated with a disease-modifying therapy (for most, this was Gilenya). Of the NMOSD patients, 6 were currently being treated (for most, the treatment was azathioprine).

Both OCTA and SD-OCT technologies were used to evaluate the patients. Here are some of the primary findings:

• For those with NMOSD and ON, the radial peripapillary capillary vessel density was lower in both the superior and the inferior sectors
• For those without ON, MS could only be distinguished by the presence of a decreased temporal sector
• Patients with NMOSD and ON experienced thinner RNFL layers within the I and the temporal quadrants than those with MS and ON
• GCC thickness and macular capillary plexuses were not able to be distinguished between ON and non-ON eyes in either patient group