Visual outcome after intravenous dexamethasone therapy for idiopathic optic neuritis in an Indian population: A clinical case series

Purpose: To evaluate the clinical profile, response to dexamethasone treatment and visual function outcome in Indian patients with acute optic neuritis. Materials and Methods: We conducted an observational study of patients with acute optic neuritis who were treated with intravenous dexamethasone (100 mg in 250 ml of 5% dextrose over 1-2 hours daily, for three consecutive days) and had completed at least two years of follow-up. Parameters assessed included visual acuity, contrast sensitivity, color vision, visual fields, relative afferent pupillary defect (RAPD) and visually evoked potentials. Out of 40 patients studied, 26 patients (33 eyes) had all visual function parameters assessed. Twenty three patients (28 eyes) had completed two years of follow-up and were included for statistical analysis. Results: Improvement in visual acuity was statistically significant for distance after 24 hours of the first dose ( P = < 0.001) and for near vision after 24 hours of the second dose ( P = 0.006); improvement in color and contrast sensitivity was statistically significant 24 hours after the third dose ( P = < 0.001 for color vision and P = 0.013 for contrast sensitivity). Significant improvement in RAPD and visual fields were seen by 1 month ( P = 0.005). Recurrence was seen in 4 eyes of 4 patients. No serious side effects were observed. At two years, 82.14% (23 out of 28) eyes had visual acuity > 20/40. Conclusion: Treatment with intravenous pulsed dexamethasone led to rapid recovery of vision in acute optic neuritis, without any serious side effects