Retinochoroidal Abnormalities In Acute Vogt-Koyanagi-Harada Syndrome By Optical Coherence Tomography Angiography

Objective: To observe the characteristics of changes in best corrected visual acuity,subfoveal choroidal thickness,vascular density in retinal and choroidal capillary layers and explore the correlation among them in Vogt-Koyanagi-Harada Syndrome.Methods: This study including 35 eyes of nineteen patients with acute VKH Syndrome who received systemic corticosteroid therapy from July 2017 to January 2019.Best corrected visual acuity(BCVA,BCVA was converted to the logarithm of minimal angle of resolution scale,logMAR),optical coherence tomography(OCT),optical coherence tomography angiography(OCTA),indocyanine green angiography,(ICGA)and fluorescein fundus angiography(FFA)were performed before treatment.Corticosteroid therapy was started with intravenous pulse methylprednisolone at 0.5 g/day for 3 days followed by oral prednisolone at an initial dose of 1.0-1.5 mg/kg of body weight/day,which was gradually tapered over a period of more than 6 months in according with intraocular inflammation improvement.We performed retrobular injection of Dexamethasone at 5mg/day and(or)topical 1%Prednisolone acetate eyedrop and 0.1%bromfenac sodium eyedrop 4 times/day if necessary.Defined initial situations including vascular density of superficial capillary plexus(SCP),deep capillary plexus(DCP)and choriocapillaris(CC),Choroidal Thickness(SCT)and BCVA as the baseline.These indicators at 1 month and 2 and 3 and 6 months followed-up during treatment were compared with the baseline.Results: The logMAR BCVA significantly decreased from baseline 0.665±0.198 to 0.399±0.131,0.248±0.079,0.149±0.066 and 0.060±0.063,showing a statistical difference(P<0.001 for all).Vascular density of SCP significantly increased from baseline 47.5±2.5% to 51.1±0.8%,52.0±0.6%,52.5%±0.6% and 52.7±0.6%,showing a statistical difference(P<0.001 for all).Vascular density of DCP significantly increased from baseline 50.2±4.1% to 56.6±1.1%,56.7±0.8%,57.5±0.8% and 57.9±0.8%,showing a statistical difference(P<0.001 for all),except the difference between 1 month and 2 month.Vascular density of CC increased from baseline 61.6±2.2% to 65.1±0.8%,65.7±0.7%,66.1±0.7% and 66.0±2.0%,showing a statistical difference(P<0.001 for all),except the difference between 3 month and 6 month.The SCT significantly decreased from baseline 744.91±27.94?m to 669.54±36.11?m,576.00±40.140?m,450.29± 34.57?m and 350.94±35.96?m,showing a statistical difference(P<0.001 for all).At the baseline,logMAR BCVA correlated significantly with vascular density of SCP(r=-0.960)and DCP(r=-0.876)and CC(r=-0.966)(P<0.001 for all).LogMAR BCVA correlated significantly with SCT(r=0.929,P<0.001).The SCT correlated significantly with vascular density of SCP(r=-0.882)and DCP(r=-0.795)and CC(r=-0.874)(P<0.001 for all).Conclusions: Visual acuity increased significantly through our corticosteroid therapy in acute VKH Syndrome.Retinochoroidal circulatory disturbances could be improved through the therapy in acute VKH.SCT could be a useful index for evaluating the choroiditis activity,circulatory disturbances and visual acuity in acute VKH.Elaborate analysis of vascular density in retinal and choroidal capillary layers provide a better index to noninvasively evaluate and monitor the etiopathogenesis and outcomes of Syndrome.