Melanin change of retinal pigment epithelium and choroid in the convalescent stage of Vogt-Koyanagi-Harada disease

AIM: To observe the melanin change of the retinal pigment epithelium (RPE) and choroid in the convalescent stage of Vogt-Koyanagi-Harada (VKH). METHODS: A retrospective study was performed on 40 eyes of 20 patients in the convalescent stage of VKH. Fundus photography (FP), multi-spectral imaging (MSI), and optical coherence tomography (OCT) were performed. RESULTS: In the VKH convalescent stage, focal RPE melanin accumulation (FRMA) was detected in 34 eyes (85%) on MSI and in 7 eyes (17.5%) on FP. FRMA was limited to the previous retinal detachment area in all 28 eyes (FRMA was detected in 34 eyes on MSI, which were enrolled, and 6 eyes lacked data in the acute stage). Sunset-glow fundus was detected in 20 eyes (50%) on FP. The mean density of FRMA in a 1-mm-diameter circular area of the fovea was 0.04±0.07 on MSI, which was significantly correlated with sunset-glow fundus (ρ=0.467, P=0.02). CONCLUSION: In the VKH convalescent stage, FRMA is derived from the RPE melanin change, and sunset-glow fundus is derived from the choroid melanin change. A higher density of FRMA in the fovea and sunset-glow fundus represents more serious depigmentation of melanin.