Abstract： [Objective] To observe the spectral domain optical coherence tomography (SD-OCT)features of acute Vogt Koyanagi-Harada (VKH) eyes before and after treatment.[Methods] Twenty-eight patients (56 eyes) with acute VKH diagnosed by slit-lamp microscopy,B mode ultrasound and fundus fluorescein angiography (FFA) were enrolled in this study.All the patients were treated with steroid after diagnosis.SD-OCT was performed in all the patients before and after treatment.The follow-up was ranged from 12 to 32 weeks with a mean of (21.30±8.53) weeks.The foveal retinal detachment height,inner and outer segments (IS/OS) of photoreceptors,and the changes in retinal structure within the vascular arcades before and after treatment were comparatively analyzed.[Results] OCT examination results showed that before treatment,all eyes had retinal neural epithelial detachment.The average neural epithelial detachment height in the fovea was (635.44±340.04) μm.Forty-three eyes (76.8％) had different types of subretinal exudates; 41 eyes (73.2％) had strong granular reflection in the subretinal space.Twenty-two eyes (39.3％) had paraforveal outer nuclear layer (ONL) thickening with finger-like protrusions attached with membrane-like structure.Thirty-three eyes (58.9％) had wavy lines of the retinal pigment epithelium(RPE).After the treatment,these exudates dissolved within one week and RPE line became straight.Theretina reattached after (2.33±0.82) weeks.In most patients external limiting membrane and IS/OS became intact after (5.01 ± 6.71) weeks and (11.40 ± 7.89) weeks respectively.However,at the end of follow-up,46 eyes (82.1％) still had focal areas of IS/OS defect and 11 eyes (19.6％) had focal ONL thinning.[Conclusion]s Before the treatment,the OCT features of acute VKH are serous retinal detachment at fovea,different types of subretinal exudates and wavy RPE.After the treatment,the OCT features of acute VKH are exudates dissolving,straight RPE line and early recovery of external limiting membrane.