Visual and Neuroimaging Outcomes following High-Dose Corticosteroid Therapy in Methanol-Induced Optic Neuropathy with Associated Bilateral Putamen Necrosis Cases

Abstract Background: Methanol poisoning is a common cause of toxic optic neuropathy, which can result in profound, often irreversible, visual loss. Optic nerve damage occurs due to formic acid–induced mitochondrial dysfunction and subsequent retinal ganglion cell death. High-dose corticosteroids are commonly administered to reduce inflammation and edema of the optic nerve; however, evidence for their long-term benefits remains limited. Aim: Valuate the effect of high-dose corticosteroid treatment on optic nerve healing and visual outcomes in individuals with acute methanol-induced optic neuropathy. Methods: Forty patients (80 eyes) with confirmed methanol poisoning were enrolled. All patients received intravenous high-dose corticosteroids. Visual acuity was assessed at baseline, immediately following corticosteroid therapy, and at 6 months, using Snellen’s chart, and converted to LogMAR for statistical analysis. Descriptive and categorical outcomes were calculated, and paired comparisons were performed using paired t-tests and Wilcoxon signed-rank tests. In addition, two patients who demonstrated bilateral putamen necrosis on MRI were analyzed in detail to compare neurological and visual outcomes following corticosteroid therapy. Results: At presentation, the mean visual acuity was poor (LogMAR 1.17, ≈6/60). After corticosteroid therapy, significant improvement was observed (LogMAR 0.51, ≈6/18), with further recovery at 6 months (LogMAR 0.41, ≈6/12-6/9). Improvements from baseline to post-therapy and from baseline to six months were highly significant ( P < 0.0001). At baseline, 60% of eyes had vision ≤6/60, but by 6 months only 5% remained severely impaired, while 25% achieved 6/6 vision. Among the two patients with bilateral putamen necrosis, one exhibited marked improvement in both visual and motor function following corticosteroid therapy, whereas the other showed only partial visual recovery with persistent neurological deficits, highlighting variability in steroid responsiveness and potential differences in central neurotoxicity. Conclusion: High-dose corticosteroids significantly improved visual outcomes in patients with methanol-induced optic neuropathy, with maximal recovery occurring early and sustained gains observed up to six months. However, patients with bilateral putamen necrosis demonstrated variable responses, suggesting that the extent of central nervous system injury may influence both visual and neurological recovery. Despite timely treatment and long-term monitoring being essential, complications such as cataract and optic atrophy remain important challenges.