Retinal Segmentation Distinguishes Neuromyelitis Optica From Multiple Sclerosis Using Optical Coherence Tomography Regardless of Antibody Status (P4.020)

Objective: To investigate differences in macular inner retinal layer thickness using spectral domain optical coherence tomography (SD-OCT) between subjects with neuromyelitis optica (NMO) and multiple sclerosis (MS). Background: Currently, it is difficult to differentiate NMO and MS at presentation. OCT has been used to study retinal neurodegeneration in a variety of disorders. Previous OCT studies investigating NMO and MS have focused on macular thickness as a whole. To date, only a few studies have evaluated macular inner retinal layers using automated segmentation SD-OCT technology. Design/Methods: SD-OCT was performed on NMO subjects and matched MS subjects to compare retinal layer thickness between the groups. Data from healthy controls were also collected. The volume and mean parafoveal thickness of the macula and 6 inner retinal layers were obtained. The inner retinal layers were separated using an automated segmentation algorithm. Results: OCT measurements of 14 NMO and 14 MS patients were analyzed. When subjects with NMO were compared to subjects with MS, statistically significant thinning was found in the NMO group in the total retina, ganglion cell layer (GCL) and inner plexiform layer (IPL). No statistically significant differences were observed between these two groups in the macular retinal nerve fiber layer or in any outer retinal layers, including the inner nuclear layer (INL). These findings were observed regardless of NMO patient antibody status. Using a threshold at the 5th percentile of control eye thickness in the macular parafovea, OCT proved 58[percnt] sensitive in detecting significant thinning in NMO, and 77[percnt] specific for the NMO disease. Conclusions: This study is consistent with previous findings of GCL and IPL retinal thinning in NMO compared to MS. In contrast to previous studies, however, no difference was observed in the INL. Importantly, using the macular parafoveal measure, we achieved a sensitivity of 58[percnt] and specificity of 77[percnt]. Disclosure: Dr. Loeb has nothing to disclose. Dr. Finch has nothing to disclose. I have received consultant fees from Teva, Bayer, Novartis, Questcor and Biogen. I have been a speaker for Bayer, Teva, Biogen, Novartis, Questcor, and Bayer., Dr. Bernard has received personal compensation for activities with Biogen Idec and Bayer as a consultant and/or speaker.