Evaluation of Melanin Changes in Acute Vogt-Koyanagi-Harada Disease Using Polarization-Sensitive Optical Coherence...

To examine melanin changes in the RPE and choroid during the acute phase of Vogt-Koyanagi-Harada (VKH) disease using polarization-sensitive optical coherence tomography (PS-OCT).

This study included 15 eyes of 8 patients with new-onset VKH disease and 5 eyes of 3 patients with posterior scleritis. PS-OCT captured a 12 × 12 mm area centered on the fovea, and en face images were created for the RPE and choroid. Polarimetric entropy within a 6-mm diameter circle centered on the fovea was calculated and compared between groups.

Choroidal polarimetric entropy was significantly lower in eyes with VKH disease than in those with posterior scleritis at baseline (0.296 ± 0.047 vs. 0.392 ± 0.050; P = 0.005; r = 0.64; 95% confidence interval, 0.42-0.74). One month after starting treatment, eyes with VKH disease showed a significant increase in choroidal polarimetric entropy (0.296 ± 0.047 to 0.350 ± 0.075; P = 0.001; r = 0.85; 95% confidence interval, 0.61-0.95), whereas no significant change was observed in eyes with posterior scleritis. RPE polarimetric entropy showed no significant changes between baseline and 1 month, with no differences between groups.

PS-OCT revealed that choroidal melanin density decreased during the acute phase of VKH disease and significantly increased after treatment. PS-OCT provides a noninvasive method for observing melanin dynamics in VKH disease and aids in differentiating it from posterior scleritis. PS-OCT could offer valuable insights into the pathology of VKH disease and its potential implications for management.