[Optical coherence tomography angiography of acute Vogt-Koyanagi-Harada disease]

Objective: To measure vascular density in retinal and choroidal capillary layers by optical coherence tomography angiography (OCTA) and to explore their potential clinical values in Vogt-Koyanagi-Harada disease (VKH). Methods: This is a cross-sectional case-control study. Twenty-one acute VKH cases presented to Peking Union Medical College Hospital between April 2015 and July 2015 and 49 healthy controls were enrolled in this study. OCTA was performed with a split-spectrum amplitude-decorrelation angiography-optical coherence tomography (SSADA-OCT) system borrowed from Optovue Inc. Vascular densities of the capillary layers were analyzed by the built-in software. Bilateral independent sample t-test was used to compare retinal and choroidal vascular density of eyes in acute phase VKH with healthy controls. Spearman correlation test was used to analyze the correlation between the vascular density of retina and choroid in acute phase VKH and LogMAR best corrected visual acuity (BCVA). Results: Mean vascular density of superficial capillary plexus (SCP), deep capillary plexus (DCP) and choriocapillaris (CC) in eyes of the acute VKH group were statistically lower than those of healthy control group (51.56%±2.88%, 56.51%±2.31%, 58.14%±2.10% vs. 53.55%±2.51%, 58.14%±2.10%, 58.14%±2.10%, t=-3.890, 3.910,-6.554, all 3 P values were<0.01). In VKH patients, eyes with retinal detachment (RD) had statistically lower mean vascular density in the CC layer than those without (NRD) (63.46%±2.19% vs. 65.85%±1.79%, t=3.890, P<0.01), while no statistically significant differences were found in vascular densities of SCP and DCP layers between RD and NRD eyes. Spearman's correlation test revealed a negative correlation between vascular density of the CC layer and logMAR BCVA(r=-0.437, P<0.01), while no statistically significant associations were found between logMAR BCVA and vascular densities of SCP and DCP. Conclusions: OCTA can be used for quantitative detection of vascular density of retina and choroidal capillary in acute VKH. There is circulatory disturbance in SCP, DCP and CC of acute VKH. Vascular density of CC is associated with visual acuity and retinal detachment. (Chin J Ophthalmol, 2017, 53: 735-739).