Etiologic Spectrum of Optic Disc Edema in Mongolia: Clinical Insights from a Resource Limited Setting

Objective: Optic disc edema (ODE) is a critical clinical sign that often marks the initial manifestation of a vision- or life-threatening systemic disease, depending on its underlying etiology. This first Mongolian observational study defines the demographic characteristics, etiologies, and clinical features of ODE, assessing diagnostic reassessment as a challenge for multiple specialties. Methods: We conducted a 5-year retrospective–prospective observational study with reassessment to evaluate etiologies, clinical features, and visual outcomes. Results: Seventy patients (90 eyes) with optic disc edema were included in the analysis. Demyelinating optic neuritis (36.4%) predominated in younger females, ischemic cases (44.4%) in older patients, and infectious causes (26.9%, syphilis) in males. Inflammatory etiologies were mostly uveitis. Baseline vision was poor, with 20% presenting with profound impairment (Visual acuity (VA)≤20/400). Severe loss (<6/120) was most frequent in demyelinating cases (72.2%). Visual recovery was most significant in demyelinating and inflammatory cases, and minimal in ischemic cases, with initial BCVA being the strongest prognostic factor (p value < 0.05). Conclusion: We conclude that optic disc edema shows a diverse age-related etiologic spectrum, with demyelinating and ischemic causes predominating, with differing prognoses and a high burden of infectious (mainly syphilis) and uveitis cases. Initial visual acuity was the key prognostic factor, emphasizing the importance of systemic screening and multidisciplinary care.