Choroidal atrophy and loss of choriocapillaris in convalescent stage of Vogt-Koyanagi-Harada disease: in vivo documentation

BACKGROUND: The aim of this study was to determine the clinical significance of posterior choroidal thickness and vascular changes in the convalescent stage of Vogt-Koyanagi-Harada disease (VKH). Macular spectral domain optical coherence tomography (SD-OCT) images of 22 eyes of 13 consecutive patients with VKH at the convalescent stage were compared to 17 eyes of 9 age/sex/refraction-matched normal subjects. The choriocapillaris layer, medium choroidal vessels (Sattler's layer), and large choroidal vessels (Haller's layer) were assessed in foveal SD-OCT scans. The presence and the extent of disruption of outer retinal structures were also noted. Inner and outer choroid boundaries were manually drawn on horizontal raster SD-OCT scans, and choroidal thickness and volume maps were generated. Correlation analysis was run to assess the association of the above parameters in the VKH patients compared to the normal subjects. RESULTS: In the eyes with convalescent stage of VKH, mean choroidal thickness in the foveal central subfield (200 ± 60 μm) was lower than in matched controls (288 ± 40 μm) (P < 0.0001). A thinner sub-macular choroid correlated with a lower visual acuity in uveitis eyes (Pearson correlation, r = -0.5089, P = 0.005). While the choriocapillaris layer was continuous and intact in all control eyes, various degrees of choriocapillaris loss were observed in 11 eyes (50%) with VKH (P < 0.0001). In these patients, the presence of outer retinal disruption was associated with a lower visual acuity (Spearman correlation, P < 0.001). CONCLUSIONS: The choroid is significantly thinner and the choriocapillaris layer is disrupted in the eyes with convalescent stage of VKH. Evaluation of the choriocapillaris in SD-OCT scans may be a useful surrogate marker for visual function in the convalescent stage of VKH.