Unveiling the retinal secrets of neuromyelitis optica spectrum disorder

Vascular alterations are now recognized as important contributors to the pathophysiology of neuromyelitis optica spectrum disorder (NMOSD). This study aimed to use optical coherence tomography (OCT) and OCT-angiography (OCTA) to assess alterations in the retinal structure and microvasculature in patients with NMOSD, so we can understand pathophysiology of NMOSD, implicating this on disease activity, visual outcome and management on the future. A case–control study was conducted on 40 NMOSD patients with (NMOSD + ON) and without (NMOSD – ON) history of optic neuritis and 36 healthy subjects. The following data were assessed in NMOSD patients: clinical history, EDSS, and visual function testing. Both groups underwent spectral domain (SD)-OCT and OCTA. In this study, NMOSD + ON patients had a statistically significant reduction in all SD-OCT parameters compared to healthy control. Regarding OCTA, there was a significant reduction in radial peripapillary capillary density (RPCD) in NMOSD + ON (P-value < 0.001) and some sectors of NMOSD–ON compared to healthy control. NMOSD + ON patients had significant differences in RPCD compared to those without (P-value < 0.001). Here we show that the advance of this study is that retinal microvascular alterations have been noticed in NMOSD–ON eyes, indicating that subclinical primary retinal vasculopathy and disease activity may occur in NMOSD before onset of ON and retinal atrophy. This may have implications on early detection of disease activity, early interference in management and prognostic tool to visual outcome in following the patients.