Possible Role of Corticosteroids in Nervous System Plasticity: Improvement in Amblyopia After Optic Neuritis in the Fellow Eye Treated with Steroids

Abstract

Objective: Amblyopia consists of reduced visual function in the absence of or ganic disease, caused by deficient visual stimulation, most commonly due to squint or refractive error. Amblyopia is thought to be reversible up until the age of ∼8 years (critical period) and is usually treated with occlusion of the fellow eye. There is re cent evidence for visual system plasticity extending beyond the critical period, sup ported by reports of improvement in visual acuity in the amblyopic eye after loss of vision in the contralateral eye. This suggests that the adult visual system exhibits suf ficient plasticity to allow such improvement. We describe here improvement in vi sual acuity in three amblyopic patients after they received high-dose intravenous glu cocorticoids for optic neuritis in the contralateral eye. Methods: Clinical and neurological evaluation added. Results: In all cases, the improvement was sustained, even after the recovery from the optic neuritis. Conclusions: Because steroids affect neural plasticity, we hypothesize that they facilitate and enhance visual improvement in amblyopia, a quality that may be tested in future controlled trials. Key Words: Am biyopia—Steroids—Plasticity—Glucocorticoids—Optic neuritis.