Depigmented atrophic lesions in sunset glow fundi of Vogt-Koyanagi-Harada disease

Abstract

Purpose: Although the depigmented, small, round to oval lesions seen in the sunset glow fundi of Vogt-Koyanagi-Harada disease are considered to represent Dalén-Fuchs nodules, there is no histopathologic evidence to support such a consideration. An attempt is made herein to clarify the nature of the atrophic lesions and distinguish them from Dalén-Fuchs nodules seen in eyes with Vogt-Koyanagi-Harada disease.

Methods: Eyes from five individuals with clinical diagnoses of Vogt-Koyanagi-Harada disease were subjected to histopathologic examination. The retinal pigment epithelial changes from early active to convalescent and late chronic recurrent stages were evaluated. Particular attention was paid to Dalén-Fuchs nodules, depigmented lesions in the sunset glow fundi, and hyperpigmentation of the chronic recurrent stage.

Results: Eyes of two individuals, one in the active stage of Vogt-Koyanagi-Harada disease and the other in the convalescent stage, showed the presence of Dalén-Fuchs nodules. The depigmented small retinal pigment epithelial lesions were seen in two individuals, both of whom exhibited the sunset glow fundus of the convalescent stage. The retinal pigment epithelial lesions represented damage or disappearance of retinal pigment epithelial cells, and the sunset glow fundus appearance was from the loss of choroidal melanocytes. The heavy pigmentation seen in fundi with the chronic recurrent stage was the result of the proliferation of retinal pigment epithelial cells.

Conclusion: The Dalén-Fuchs nodule is a specific histologic change observed at the level of retinal pigment epithelium in patients with Vogt-Koyanagi-Harada disease. There is no histologic confirmation that the depigmented small atrophic lesions seen in the sunset glow fundi of Vogt-Koyanagi-Harada disease are Dalén-Fuchs nodules. The depigmented lesions represent localized damage or disappearance of retinal pigment epithelial cells.