Abstract
INTRODUCTION: The involvement of ocular system especially optic neuritis (ON) is an important clinical aspect of inflammatory demyelinating disease (IDD) of the central nervous system. The primary IDD spectrum includes neuromyelitis optica spectrum disorders (NMOSD), myelin oligodendrocyte glycoprotein-associated diseases (MOGAD), multiple sclerosis (MS), and clinically isolated syndrome (CIS). The clinical presentation of ON varies according to disease pathophysiology. AIM: We aimed to determine the clinical characteristics of treatment-naïve ON at baseline and on the 6-month follow-up and assessed the predictors of visual outcome. METHODS: A prospective study of patients with treatment-naïve ON was performed with structural and functional ophthalmological evaluation. Univariate and multivariate logistic regression analyses were used to determine the predictive factors of visual outcome. RESULTS: Out of 46 patients of IDD, ON occurred in 30 patients. The etiological subtyping included NMOSD (10), CIS (8), MOGAD (7), and MS (5) patients in our study. The ON group showed female preponderance, greater delay in diagnosis, and significant relapsing course. Bilaterality occurred predominantly in NMOSD followed by MOGAD. Optical coherence tomography analysis showed predominant thinning of superior and inferior quadrants in retinal nerve fiber layer (RNFL) and global thinning of Ganglion cell inner plexiform layer (GC-IPL) in NMOSD, but the values were not statistically significant. Univariate analysis for predictors of visual outcome showed age at onset, delay in diagnosis, NMOSD, longitudinally extensive ON (LEON) and chiasmal lesions were associated with poor outcome, while multivariate analysis showed statistical association of NMOSD and LEON with poor outcome. CONCLUSION: NMOSD and longitudinally extensive optic neuritis showed poor ophthalmological outcome and optical coherence tomography was unyielding.