Volumetric evaluation of choroidal depigmentation in the eyes with Vogt–Koyanagi–Harada disease using polarization-sensitive OCT

Abstract

Purpose : The sunset glow fundus (SGF) appearance is an important finding of Vogt–Koyanagi–Harada (VKH) disease, originated from the choroidal depigmentation. We used polarization-sensitive OCT (PS-OCT) for volumetric evaluation of choroidal depigmentation.

Methods : We evaluated 40 eyes (20 patients) with chronic VKH disease and 59 healthy eyes (59 age-matched controls) with 1-μm swept-source PS-OCT. Eyes with VKH disease were divided into three groups according to color fundus images: sunset (17 eyes), potential sunset (13 eyes), non-sunset (10 eyes). The mean thickness of melanin containing tissue in choroid (thickness of MeCh: thickness of low degree of polarization uniformity (<0.8) area within the choroidal interstitial stroma) and the mean choroidal melanin occupancy ratio (occupancy of the low degree of polarization uniformity area within the choroidal interstitial stroma) within a 5-mm circular region from the foveal center were calculated. To evaluate regional variations, the 5-mm circular region was divided into a center area and an outer ring area.

Results : The mean thickness of MeCh was significantly lower in sunset eyes than non-sunset or control eyes (P = 0.003). The mean choroidal melanin occupancy ratio of sunset or potential sunset eyes were significantly lower than non-sunset or control eyes (P = 0.04). The area under the receiver operating characteristic curves for the combined sunset group (sunset and potential sunset) and the non-sunset group were 0.983 and 0.997 for the thickness of MeCh and the choroidal melanin occupancy ratio, respectively. Regional evaluation of thickness of MeCh and the choroidal melanin occupancy ratio showed that choroidal depigmentation predominantly occurred in the macula’s outer ring area (P = 0.002). Time course evaluation of 12 eyes for 18 months from disease onset showed that both thickness of MeCh and choroidal melanin occupancy ratio significantly decreased over time.

Conclusions : PS-OCT is useful for objective evaluation of choroidal depigmentation of the SGF in VKH disease.

This abstract was presented at the 2022 ARVO Annual Meeting, held in Denver, CO, May 1-4, 2022, and virtually.

 

Representative cases of healthy control, non-sunset, potential sunset and sunset.