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

Abstract

PURPOSE. Clinical evaluation of retinal pigment epithelium (RPE) change is important for the therapeutic management of chronic Vogt-Koyanagi-Harada (VKH) disease. We evaluated longterm 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, polarizationsensitive OCT, and standard OCT. METHODS. 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. RESULTS. 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. CONCLUSIONS. 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.

Evaluation of retinal pigment epithelium changes in serous pigment epithelial detachment in age-related macular degeneration

“…From the MC-OCT dataset, we derived RPE-melanin-specific contrast OCT (RPE-melanin OCT) images, which we used to evaluate RPE changes 26 . In our previous studies of patients with AMD 26 and patients with Vogt-Koyanagi-Harada disease 25 , we confirmed similarities between NIR-AF images and RPE-melanin OCT projection images. Thus, the combination of RPE-melanin OCT and AF imaging might be useful for evaluation of RPE changes in PED.…”

“…Therefore, RPE-melanin thickness maps do not represent the actual thickness of RPE-melanin, although they are proportional to the thickness of the RPE-melanin. Seventh, a threshold of F RPE (≥ 0.15) in MC-OCT imaging was used to calculate the area of RPE melanin defects, in accordance with the method used in our previous studies 9,25,26 . With this threshold, the RPE-melanin line at the normal RPE band occasionally became unclear (Fig.…”

“…However, the evaluation of RPE changes by polarization-sensitive OCT has some limitations, including a lack of discriminability between melanin in the RPE (RPE-melanin) and melanin in the choroid. In projection images captured by polarization-sensitive OCT, RPE changes are obscured by depolarization involving choroidal melanin 25 . To overcome this limitation, we developed an automatic highlighting algorithm for RPE-melanin using multi-contrast OCT (MC-OCT) 26 , which enables simultaneous collection of OCT angiography, polarization-sensitive OCT, and standard OCT images [27][28][29] .…”

Retinal Pigment Epithelial Characteristics in Acute and Resolved Vogt-Koyanagi-Harada Disease

“…Thus, we speculated that a few changes might be occurring at the level of the retinal pigment epithelium (RPE) that is causing these changes. While few imaging studies have analyzed RPE, both following the resolution of the disease and in the chronic phase, describing features such as focal areas of reversible RPE thickening and RPE atrophy, there is a lacuna in the literature regarding RPE imaging characteristics during the acute phase and immediately following resolution of the disease [ 8 , 9 , 10 ]. Thus, in the current study, we aimed to assess the morphological features of the more easily scanned RPE during the acute phase of the disease and following resolution and its probable role as a biomarker for the diagnosis and assessing the severity of VKH.…”

Nahinfrarot-Autofluoreszenz: klinische Anwendung und diagnostische Relevanz

“…Ebenso können sich granuläre Läsionen mit erhöhter NIA-Intensität zeigen, die sich im weiteren Verlauf abschwächen. Diese Läsionen sind mit der FAF nicht eindeutig darstellbar [26].…”