Diagnosis and classification of Vogt-Koyanagi-Harada disease

Vogt-Koyanagi-Harada (VKH) disease is a systemic autoimmune disorder that affects pigmented tissues of the body, with its most dire manifestations affecting the eyes. This review focuses on the diagnostic criteria of VKH disease, including some information on history, epidemiology, appropriate clinical and classification criteria, etiopathogenesis, treatment and outcomes. Expert review of most relevant literature from the disease's first description to 2013 and correlation with the experience in the care of VKH disease patients at a tertiary Uveitis Service in Brazil gathered over the past 40 years. The clinical manifestations and ancillary assessment of VKH disease have been summarized in the Revised Diagnostic Criteria proposed in 2001 in a manner that allows systematic diagnosis of both acute and chronic patients. It includes the early acute uveitic manifestations (bilateral diffuse choroiditis with bullous serous retinal detachment and optic disk hyperemia), the late ocular manifestations (diffuse fundus depigmentation, nummular depigmented scars, retinal pigment epithelium clumping and/or migration, recurrent or chronic anterior uveitis), besides the extraocular manifestations (neurological/auditory and integumentary). There are two exclusion criteria, i.e. absence of previous ocular penetrating trauma or surgery and any other ocular disease that could be confounded with VKH disease. HLA-DRB1*0405 plays an important role in pathogenesis, rendering carriers more susceptible to disease. The primary ocular pathological feature is a diffuse thickening of the uveal tract in the acute phase. Later on, there may be a compromise of choriocapillaris, retinal pigment epithelium and outer retina, mostly due to an "upstream" effect, with clinical correlates as fundus derangements. Functional tests (electroretinogram and visual field testing) as well as imaging modalities (retinography, fluorescein/indocyanine green angiography, optical coherence tomography and ultrasound) play an important role in diagnosis, severity grading as well as disease monitorization. Though high-dose systemic corticosteroids remain gold-standard therapy, refractory cases may need other agents (cyclosporine A, anti-metabolites and biological agents). In spite of good visual outcomes in the majority of patients, knowledge about disease progression even after the acute phase and its impact on visual function warrant further investigation.