Traumatic Optic Neuropathy: Early Detection and Intervention in a Tertiary Care Centre

Abstract

Introduction: Acute injury to the optic nerve resulting in vision loss is known as Traumatic Optic Neuropathy (TON). Optical Coherence Tomography (OCT) documents the progression of damage of axons over time. Aim: To assess visual outcome of patients diagnosed with TON after management with intravenous (IV) steroids and to study Retinal Nerve Fiber Layer (RNFL) using OCT in patients with TON. Materials and Methods: An observational prospective study was conducted in a tertiary care centre, including 29 TON patients. IV steroids, methylprednisolone was administered in indirect TON patients. RNFL was assessed using OCT on the day of discharge. Follow-up for one week and one month after discharge. Paired t-test/Wilcoxon sign rank test was applied to test the mean differences of the study. Results: Patients treated with IV, steroids showed significant improvement over time. Patients with just Perception of Light (PL) or Hand Movements (HM+) did not show much improvement. Another factor for visual recovery was timing of steroid administration. The time limit was within 24 hours after the injury before full-fledged inflammation sets in. RNFL study using OCT showed reductions in circumpapillary RNFL thickness and Retinal Ganglion Cell (RGC) complex began to decrease at two weeks after trauma and plateaued at 20 weeks in all cases. Conclusion: IV steroids can be considered as a treatment of TON rather than wait for spontaneous recovery. But baseline visual acuity played a crucial role in recovery. OCT is a useful follow-up tool to analyse axonal loss. But a standard protocol is still lacking.

Keywords

• axonal loss in traumatic optic neuropathy
• circumpapillary retinal nerve fiber layer
• optical coherence tomography
• retinal ganglion cell complex