Choroidal thickness in eyes with posterior recurrence of Vogt–Koyanagi–Harada disease after high‐dose steroid therapy

Abstract

Vogt–Koyanagi–Harada (VKH) disease shows thickened choroid at the acute stage (Maruko et al. 2011; Fong et al. 2011), and the thickness decreases progressively during the recovery phase (Nakai et al. 2012). In VKH, recurrence of inflammation is relatively common after initial steroid therapy and may develop ocular complications causing poor visual function; however, a detailed study of the choroidal thickness during a recurrence has not been determined. This letter reports changes of choroidal thickness in eyes with posterior recurrences of VKH. We studied 29 consecutive patients with VKH, treated with steroid pulse therapy and then with low-dose oral steroid, retrospectively. All of the eyes were examined with the Heidelberg Spectralis optical coherence tomography (OCT) (Heidelberg Engineering, Heidelberg, Germany) with eye tracking and image averaging systems to obtain choroidal images during the recurrences and after high-dose steroid therapy. The choroidal thickness was measured with the enhanced depth imaging OCT (EDI-OCT) technique as described previously (Spaide et al. 2008). A posterior recurrence was defined as a posterior inflammation which appeared at least 3 months after an initial high-dose steroid therapy and required a higher dose of systemic steroid therapy. The significance of the differences in the choroidal thickness was determined with the Wilcoxon signed-rank test. A p < 0.05 was considered statistically significant. Nine of the 29 patients with VKH had posterior recurrence during the follow-up period. The posterior recurrence was bilateral in seven of the nine eyes, and eight of the nine patients had a posterior recurrence once and one had it twice during the follow-up period. The choroidal thickness of the eyes showing posterior recurrences was 749 ± 60 (means ± standard error of the means (SEM)) μm, which was significantly larger than that before the recurrence (348 ± 18 μm, p < 0.001). After the higher-dose steroid therapy, the choroidal thickness decreased to 351 ± 37 μm at 2 weeks (p < 0.001) and to 352 ± 56 μm at 1 month (p < 0.01) after beginning the therapy (Fig. 1A). The EDI-OCT images of representative VKH case with a posterior recurrence are shown in Fig. 1B–E. As can be seen, the choroid is significantly thicker and the outlines of the choroidal vessels were unclear during the posterior recurrences. Our results showed that the choroid was thicker at posterior recurrence in patients with VKH disease. When a higher dose of steroid was given, the choroid became thinner within 2 weeks. The thickening of the choroid was detected by EDI-OCT in eyes with VKH at the acute stage (Maruko et al. 2011; Fong et al. 2011). Our results showed that a similar thickening occurred in eyes at posterior recurrence. Our results strongly suggest that a thickened choroid may be a hallmark of a recurrence, and the choroidal thickness can be used to determine the dose and timing of the tapering of the steroids. At present, indocyanine green angiography (ICGA) is used to assess choroidal inflammation in VKH, and earlier studies suggested that the angiographic signs may indicate choroidal inflammations (Bouchenaki and Herbort 2011). However, performing ICGA is invasive and not very quantitative. EDI-OCT is a non-invasive and quantitative method and can be used to assess the degree of choroidal inflammatory reactions during the follow-up. There are several limitations of this retrospective study. The number of cases was relatively small, no control group was studied, and the length of follow-up was different. More cases with longer follow-up periods are needed to determine the correlation between the choroidal thickness and various ocular manifestations during recurrences of VKH disease.