1. Automatic measurement of choroidal thickness with Swept-Source OCT in acute Vogt-Koyanagi-Harada
Dra. Olga Garcia-Garcia, Dra. Natalia Diaz-Sanchez, Dr. Olaia Subira-Gonzalez, Dr. Pere Garcia-Bru, Dr. Javier Aguayo, Dr. Luis Arias, Dr. Josep M. Caminal Hospital Universitari de Bellvitge Barcelona

2. Key points- Purposes
The course of acute Vogt-Koyanagi-Harada is typically assessed qualitatively using indocyanine green angiography (ICGA).
Swept-source optical coherence tomography (SS-OCT) may provide a safer, non-invasive, quantitative and more objective approach to follow up.
In this study, we assess the clinical value of the automated measurement capabilities of SS-OCT to measure choroidal thickness (quantitative approach).

3. Material & Methods
Prospective, longitudinal case-control study at a tertiary university hospital, 2 years follow-up.
Participants: Nine patients with acute Vogt-Koyanagi-Harada syndrome (18 eyes) and 17 age-matched controls (34 eyes).
Subfoveal choroidal thickness was automatically measured with SS-OCT (Atlantis DRI-1, Topcon, Japan).
Individualyzed analysis: changes in thickness were compared to changes in visual acuity (VA) and ICGA findings to check for correlations.

4. Results
At baseline, patients presented significantly greater mean (SD) subfoveal choroidal thickness than controls μm (258.3) vs (71.4) p =
Choroidal thinning and improved vision were associated with treatment.
Increasing thickness and worsening vision were associated with posterior relapse.
In 62.5% of recurrences in SS-OCT, no changes in VA were present
All recurrences diagnosed with SS-OCT showed signs of inflammation on ICGA.

6. Changes in choroidal thickness (micrometers- μm) and visual acuity from baseline to study end in patient 1.

7. Changes in choroidal thickness (micrometers- μm) and visual acuity from baseline to study end in patient 5.

8. Conclusions
Automatic measurement of choroidal thickness with SS-OCT 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.