Introduction:

Vogt–Koyanagi–Harada (VKH) disease is a rare, bilateral, chronic, idiopathic, granulomatous panuveitis. It occurs predominantly in females, usually between 30 and 50 years old, with a propensity for dark pigmented races: Asians, Hispanics, Native Americans and Asian Indians. An immune reaction to uveal melanocytes has been proposed as the mechanism, but the cause largely remains unknown.

Clinical Features:

Initially, VKH was classified as two separate diseases:

Considering the considerable overlap in the features, the term VKH disease is now used.

At onset, patients may experience flu-like symptoms, central nervous system signs, optic neuropathy, sensitivity of hair and skin to touch, perilimbal vitiligo, alopecia, vitiligo poliosis and auditory signs. Blurred vision, photophobia, conjunctival hyperemia, and ocular pain also occur. Bilateral anterior and exudative posterior uveitis is typical. Shallow, serous retinal detachments are seen at the posterior pole with underlying choroidal infiltrates (Fig. 17.4.1). The optic disc is edematous and hyperemic.

With resolution of the uveitis and retinal detachments, a gradual depigmented appearance of the choroid (sunset-glow fundus) may develop.

OCT Features:

OCT reveals serous retinal detachments at the macula. The subretinal fluid may reveal a higher optical density than the vitreous, suggesting a higher level of protein content (Figs 17.4.2 and 17.4.3). Inner retinal layers are typically well preserved with cystic changes and complex infolding in the outer retinal layers. Subretinal fibrinoid deposits are seen, which may later evolve into subretinal fibrosis. Vitreoretinal interface alterations with cellular deposits may also be seen. There may be alteration and thickening of the IS–OS junction/ellipsoid layer, RPE and choroidal folds, and thickening of the choroid. Enhanced depth imaging OCT will show significant choroidal thickening, which resolves when treated.

Ancillary Testing:

On fluorescein angiography, active disease with subretinal exudation appears as multiple hyperfluorescent dots at the RPE level, which gradually enlarge and coalesce as the dye accumulates in the subretinal space. With resolution of the exudative phase, these features no longer are visualized. The chronic phase is characterized by diffuse scattered hyperfluorescent dots corresponding to window defects at the RPE level.

On fundus autofluorescence, serous detachments are observed to be hypoautofluorescent, due to blockage. Hypoautofluorescent multiple, granular dots are seen after resolution, which correspond to the window defects on FA.

On indocyanine green angiography, active disease is characterized by choroidal stromal vasculature hyperfluorescence and leakage, disc hyperfluorescence, hypofluorescent dots, and indistinct, fuzzy large choroidal vessels with decreased dye filling.

Treatment:

Topical, periocular and systemic steroids are instituted as therapy, along with topical cycloplegics. In chronic or non-responsive cases, or when side effects from steroids are severe, other agents are employed including cyclosporine, chlorambucil, cyclophosphamide, azathioprine or infliximab.