Chorioretinal Changes In Acute And Convalescent Vogt-Koyanagi-Harada Disease By Optical Coherence Tomography Angiography

Objective:To observe the characteristics of changes in visual acuity,subfoveal choroidal thickness and vascular density in retinal and choroidal capillary layers and to explore the correlation between them in Vogt-Koyanagi-Harada disease(VKH).Methods:This is a prospective observational study,27 acute VKH cases presented to Peking Union Medical College Hospital between April 2015 and March 2017 and 49 healthy controls(HC)were enrolled in this study.Optical coherence tomography angiography(OCTA)was obtained by a split-spectrum amplitude-decorrelation angiography-optical coherence tomography(SSADA-OCT)system(Optovue Inc)at presentation and regularly during 6-month follow-up.Results:There was an arresting increase in best corrected visual acuity(BCVA)and vascular densities of all retinal and choroidal layers along with thinning of subfoveal choroidal thickness(SCT)in VKH group during the acute uveitic stage.While BCVA remained sable in convalescent stage,SCT and vascular density of choriocapillaris(CC)decreased slowly.The vascular densities of superficial capillary plexus(SCP),deep capillary plexus(DCP)and CC,and SCT of VKH at acute uveitic stage were statistically lower than healthy control group(HC)(all 3 P values were<0.05,t=-2.797,-3.337,-3.010,11.358,respectively).In convalescent stage,vascular density of SCP of VKH group was statistically lower than HC(P<0.05,t=-1.990),while there was no significant differences between convalescent VKH and HC groups in vascular densities of DCP and CC,and SCT.In acute VKH,spearman correlation tests revealed negative correlations between logMAR BCVA and vascular densities of the SCP,DCP and CC,respectively(all 3 P values were<0.05,R=-0.499,-0.428,-0.333,respectively),and between vascular density of the CC and SCT(P<0.05,R=-0.380);while no significant correlation was found between logMAR BCVA and SCT.Conclusions:OCTA can be used for quantitative evaluation of vascular densities of retinal and choroidal capillary layers in VKH.There is a significant increase in BCVA and vascular densities of all retinal and choroidal layers while a sharp thinning of subfoveal choroidal thickness(SCT)through the systematic anti-inflammatory treatment of the acute VKH.In acute VKH,correlation test revealed a negative correlation between vascular density of the SCP,DCP and CC and logMAR BCVA,vascular density of the CC and SCT,respectively.While no significant associations were found between logMAR BCVA and SCT.Vascular densities of retinal and choroidal layers may become alternative imaging indicators apart from SCT for surveillance of VKH.