Automatic Measurement of Choroidal Thickness with Swept-Source Optical Coherence Tomography for Clinical Follow-Up in Acute Vogt-Koyanagi-Harada Disease

Abstract

Background: The course of acute Vogt-Koyanagi-Harada is typically assessed qualitatively using indocyanine green angiography. Swept-source optical coherence tomography may provide a safer, non-invasive, more objective approach to follow up. In this study, we assess the clinical value of the automated measurement capabilities of swept-source tomography to measure choroidal thickness. Design: Prospective, longitudinal case-control study at a tertiary university hospital. Participants: Nine patients with acute Vogt-Koyanagi-Harada disease (18 eyes) and 17 age-matched controls (34 eyes). Methods: Choroidal thickness (subfoveal area and ETDRS grid) was automatically measured with swept-source optical coherence tomography. Changes in thickness were compared to changes in visual acuity and indocyanine green angiography findings to check for correlations. Main outcome measures: Changes in choroidal thickness (micrometers- μm) from baseline. Secondary measures included visual acuity and angiography. Results: At baseline, patients presented significantly greater mean (SD) subfoveal choroidal thickness (666.9 μm [258.3] vs. 302.3 [71.4]) and ETDRS grid choroidal thickness (648.7 μm [260.5] vs. 287.5 [69.3]) than controls (p=0.000). Choroidal thinning and improved vision were associated with treatment while increasing thickness and worsening vision were associated with posterior relapse. In 62.5% of recurrences in tomography, no changes in visual acuity were present; however, all recurrences diagnosed with tomography showed signs of inflammation on angiography. Conclusions: Automatic measurement of choroidal thickness with swept-source optical coherence tomography is a rapid, non-invasive manner of detecting posterior segment recurrences and treatment response in acute Harada patients. Swept-source tomography could reduce the need for angiography to monitor patients with Harada disease.