Visual Outcomes After Radiotherapy and Radiosurgery for Optic Pathway Hypothalamic Glioma: A Systematic Review and Meta-analysis

Background Optic pathway hypothalamic glioma (OPHG) can cause irreversible visual impairment. Radiotherapy and radiosurgery are used for progressive, recurrent, or treatment-refractory disease, but their effects on visual outcomes remain incompletely defined. Objective To synthesize visual outcomes following radiotherapy or radiosurgery for OPHG, with visual preservation as the primary outcome. Methods This prospectively registered systematic review and meta-analysis (PROSPERO CRD420261440136) followed the PRISMA 2020 statement. PubMed, Scopus, Web of Science, Embase, the Cochrane Library, Google Scholar, and ClinicalTrials.gov were searched from inception to 1 June 2026. Eligible studies included patients with OPHG or related optic pathway or hypothalamic gliomas treated with radiotherapy or radiosurgery and reporting extractable visual outcomes. Visual preservation was defined as stable or improved vision. Random-effects meta-analyses of logit-transformed proportions were performed. Results Forty-nine studies were included in the systematic review, of which 19 contributed 494 visual outcome observations to the meta-analysis. The pooled visual preservation rate was 75.6% (95% CI 65.1% to 83.7%; I2 = 71.6%). Pooled rates of visual improvement, stability, and worsening were 24.7% (95% CI 19.5% to 30.8%), 46.7% (95% CI 37.0% to 56.6%), and 20.6% (95% CI 12.7% to 31.6%), respectively. Preservation was higher in pure radiotherapy or radiosurgery cohorts than in mixed-treatment cohorts (85% vs 66%; subgroup p = 0.0104), although differences in cohort composition and treatment attribution may have influenced this finding. Conclusion Radiotherapy and radiosurgery were associated with preservation of vision in approximately three-quarters of evaluable outcomes, predominantly through visual stability rather than recovery. Standardized visual outcome definitions are needed to improve future comparisons and treatment evaluation.