Importance Factors affecting visual acuity prognosis after gene therapy in Leber's hereditary optic neuropathy (LHON) patients with mutation at site 11 778 are unknown. Background To analyse correlations between visual acuity prognosis and baseline characteristics of LHON after rAAV2-ND4 gene therapy. Design Retrospective study. Participants Fifty-three LHON patients with a mutation at site 11 778. Methods Single-eye intravitreal injection of rAAV2-ND4. Main Outcome Measures Sex, onset age, duration of disease, best-corrected visual acuity (BCVA), visual field index (VFI) and mean deviation (MD) were recorded for all patients at baseline. BCVA was recorded at 1- and 3-month follow-up visits after gene therapy. Correlations between BCVA prognosis and baseline characteristics were analysed by univariate analysis. Logistic regression analysis was performed on independent factors affecting BCVA prognosis. Results Univariate analysis showed significant differences in the VFI and MD of the injected eye between BCVA improvement and non-improvement groups after 3 months of treatment, with greater VFI and smaller absolute MD in the BCVA improvement group. Logistic regression showed that VFI and baseline BCVA were independent prognostic factors for visual acuity. The correlation between VFI and MD was statistically significant. Conclusions and Relevance VFI and baseline BCVA were correlated with the visual acuity prognosis of LHON patients receiving gene therapy, with greater baseline VFI and better baseline BCVA predicting better visual acuity prognosis. MD was strongly correlated with VFI and might be correlated with gene therapy prognosis. This finding may form a basis for predicting the efficacy of gene therapy in these patients and guiding subsequent treatment.