Frequency of Isolated Optic Neuritis in Cases of Visual Impairment

Abstract

Visual impairment can result from various conditions of eye as well as neural pathways that are responsible to transmit visual inputs to the brain. One of the most common of these diseases is termed as optic neuritis which is basically an inflammatory disorder and effects the optic nerve. Objective: To find the frequency of the isolated optic neuritis among subjects with visual impairment. Method: We conducted an analytical cross-sectional study in the Department of Neurology at the Mayo Hospital. Total 93 subjects fulfilling the inclusion criteria were taken into the study for data collection. All cases underwent visual acuity assessment using Snellen's and near vision charts. Ishihara chart was used to assess color vision along with a fundoscopic examination. Isolated optic neuritis was defined as the presence of one or more of three defects on assessment, i.e., relative afferent pupillary, visual field, and the color vision defect. Results: The mean age of patients was 45.45 ± 14.42 years. There were 53.8% male and 46.2% female cases, with a higher male-to-female ratio. Isolated optic neuritis was diagnosed in 24.7% of cases of vision impairment. Conclusions: Isolated optic neuritis was diagnosed in almost one-quarter of the patients (24.7%). So, patients presenting with visual impairment must be screened for isolated optic neuritis as optic neuritis is easily distinguished from other diseases affecting the optic nerve by using Snellen's chart and near vision chart and fundoscopic examination and eventually can prevent permanent blindness.