Evaluation of Retinal Pigment Epithelium Layer Change in Vogt-Koyanagi-Harada Disease With Multicontrast Optical Coherence Tomography

Clinical evaluation of retinal pigment epithelium (RPE) change is important for the therapeutic management of chronic Vogt-Koyanagi-Harada (VKH) disease. We evaluated long-term change in the RPE layer in VKH disease, using near-infrared (NIR; 817 nm) images and autofluorescence images at 488 nm (short-wavelength [SW]-AF) and 785 nm (NIR-AF), and compared those images with images from multicontrast optical coherence tomography (MC-OCT). MC-OCT is capable of simultaneous measurement of OCT angiography, polarization-sensitive OCT, and standard OCT. We evaluated 24 eyes of 12 patients with chronic VKH disease. RPE changes were assessed using NIR, NIR-AF, SW-AF, and MC-OCT imaging performed from 6 to 48 months after disease onset. RPE-melanin-specific contrast OCT images were calculated using the dataset from MC-OCT. Granular hyper NIR-AF lesions were observed in 8 of 24 eyes (33%). Eyes with granular hyper NIR-AF lesions showed a sunset glow fundus appearance significantly more frequently than did eyes without such lesions (P < 0.0001). MC-OCT imaging confirmed that there was melanin accumulation at the RPE-Bruch's membrane band at the location of granular hyper NIR-AF lesions. Granular hyper NIR-AF lesions were unclear in SW-AF and color fundus images, but clearly detectable in NIR images. Areas of hyper NIR-AF lesions gradually decreased over time. Melanin accumulation in the RPE layer at the location of granular hyper NIR-AF lesions was confirmed with MC-OCT imaging. Long-term follow-up showed the reversible nature of this accumulation. MC-OCT is useful for the evaluation of change at the RPE layer in chronic VKH disease.