Analysis of spectral domain optical coherence tomography measurements in optic neuritis: differences in neuromyelitis optica, multiple sclerosis, isolated optic neuritis and normal healthy controls

Purpose: To compare the retinal layer thickness of eyes with optic neuritis (ON) and that of control eyes and ON eyes with and without neuromyelitis optica (NMO) or multiple sclerosis (MS). Methods: Horizontal and vertical SD-OCT scans of the fovea were undertaken for 56 patients with ON with and without NMO or MS and for 24 healthy controls. Patients with ON were divided into three groups: NMO, MS and isolated ON without NMO or MS. The thickness of each retinal layer was compared between ON and healthy control eyes, and between ON eyes with and without NMO or MS. Results: Compared with healthy control eyes, ON eyes showed significant thinning of the ganglion cell layer plus the inner plexiform layer (GCL+IPL) at all eight inner and outer macular locations. Significant differences in thickness were observed for the retinal layers of NMO, MS and isolated ON without NMO or MS at several retinal locations. Conclusions: Our SD-OCT data revealed a notable difference in the GCL+IPL thickness between ON and healthy control eyes. It also showed differences in the thickness of several retinal layers for ON subgroups including NMO, MS and isolated ON. This may be helpful for distinguishing the aetiology of ON.