Purpose <p>High-dose steroid therapy is commonly used for Vogt-Koyanagi-Harada (VKH) disease in Japan, but the optimal initial dose remains uncertain. This study investigated the efficacy and safety of conventional steroid pulse therapy (pulse group) and half-dose steroid pulse therapy (half-pulse group) for the initial treatment of VKH disease.</p> Study design <p>This was a single-center, retrospective observational study based on a review of medical records.</p> Subjects and methods <p>Seventy-two patients with initial-onset VKH disease treated at Tokyo Medical University Hospital were analyzed. The pulse group (44 patients) received 1000&#xa0;mg/day of intravenous methylprednisolone (MPSL), while the half-pulse group (28 patients) received 500&#xa0;mg/day of MPSL. In both groups, steroids were tapered according to ocular findings, and the minimum follow-up period was eight months.</p> Results <p>Recurrence rate during follow-up period (pulse group: 41%, half-pulse group: 34%, p = 0.48), mean number of recurrences (pulse group: 1.9 ± 1.2, half-pulse group: 1.5 ± 0.9, p = 0.42), and type of recurrence (anterior uveitis: pulse group: 11%, half-pulse group: 17%, p = 0.33; posterior inflammation: pulse group: 34%, half-pulse group: 22%, p = 0.14) were not significantly different between the two groups. The proportion of patients requiring cataract surgery during the follow-up period tended to be higher in the pulse group (pulse group: 10%, half-pulse group: 3%, p = 0.12), although not significantly different. The incidence of sunset glow fundus was not significantly different between the two groups (pulse group: 23%, half-pulse group: 10%, p = 0.22).</p> Conclusions <p>No significant difference in clinical efficacy for VKH disease was observed between conventional steroid pulse therapy and half-pulse therapy, and by reducing the total steroid dose, half-pulse therapy potentially lowers the risk of adverse effects related corticosteroid.</p>