Indocyanine green angiography in Vogt–Koyanagi–Harada disease: angiographic signs and utility in patient follow-up

Purpose Firstly, to give a review of characteristic indocyanine green angiographic (ICGA) signs in Vogt–Koyanagi–Harada (VKH) disease and, secondly, to determine the utility of ICG angiography in the assessment and follow-up of choroidal inflammatory activity during initial high-dose inflammation suppressive therapy and during the tapering of therapy.

Methods We have first reviewed characteristic ICGA signs in VKH. This is followed by a study of four patients with an acute initial VKH uveitis episode who received regular initial and follow-up angiographic examinations for at least 9 months. Classical ICGA signs were recorded at onset and followed for at least 9 months and were correlated with treatment levels. The treatment consisted of high-dose oral corticosteroids (0.8–1.5 mg/kg) preceded by pulse intravenous methylprednisolone (500–1000 mg) for 3 days in hyperacute cases and followed by very slow tapering with the addition of an immunosuppressive agent in cases of insufficient response.

Results The major ICGA signs that were both consistently present and easy to record in the four VKH patients having an acute initial uveitis episode with a pre-treatment angiography and an angiographic follow-up for a minimum of 9 months include (1) early choroidal stromal vessel hyperfluorescence and leakage, (2) hypofluorescent dark dots, (3) fuzzy vascular pattern of large stromal vessels and (4) disc hyperfluorescence. All patients were treated with high-dose inflammation suppressive therapy: in two patients, within 14 and 21 days after initial symptoms, respectively, and in the other two patients, within 6 weeks. Hypofluorescent dark dots, the most constant and easily recordable sign, was very prominent in all cases at presentation. A 90% to complete resolution of dark dots was noted in all four patients after 4 months of therapy. The other three major angiographic signs, early choroidal stromal vessel hyperfluorescence and leakage, indistinct fuzzy vessels at the intermediate angiographic phase and disc hyperfluorescence resolved in all cases within 8 weeks or less of high-dose inflammation suppressive therapy. In three of the four patients, dark dots reappeared after a mean of 7.8 ± 2.8 months after onset of therapy when the patients were under a mean corticosteroid dose of 13.2 ± 6.3 mg per day without any significant clinical or fluorescein angiographic signs, indicating subclinical recurrence. An increase in the inflammation suppressive therapy again brought about angiographic resolution of choroidal subclinical disease in all cases.

Conclusion Choroidal inflammation shown by ICG angiography can be suppressed completely by initial high-dose inflammation suppressive therapy. However, recurrent subclinical choroidal inflammation is detected at the end of the tapering period in a high proportion of cases. This indicates that, in the absence of an ICGA follow-up, undetected smoldering subclinical disease may persist, thereby explaining the frequently reported evolution towards sunset glow fundus despite an apparently controlled disease. This is a clear indication that VKH disease should be followed by ICG angiography and, in the case of choroidal subclinical reactivation, a reversal of therapy tapering and an extension of therapy duration should be considered.