Age-related changes in choroidal thickness and the volume of vessels and stroma using swept source OCT and fully automated algorithms

Abstract Purpose To determine age-related changes in choroidal thickness and the volume of choroidal vessels and stroma using automated algorithms based on structural swept source OCT (SS-OCT) scans. Design Prospective and observational study. Participants One hundred and forty-four normal subjects with ages ranged from 20 to 88 years. Methods A previously reported strategy was used to automatically segment the choroid using SS-OCT structural images. Attenuation correction was applied on B-scans to enhance the choroidal contrast and facilitate more accurate automatic segmentation of the 3D choroidal vessel and stroma. The parameters investigated included mean choroid thickness (MCT), choroidal vessel volume (CVV), choroidal stroma volume (CSV), choroid vascularity index (CVI), and the choroidal stroma-to-vessel volume ratio (CSVR). Correlations between MCT and choroidal vessel metrics of CVV, CSV, CVI, and CSVR were studied. Regional distributions of MCT and CVI were analyzed using a grid centered on the fovea. Age-related changes in MCT, CVV, CSV, and CVI were studied in the whole scanning region, as well as in the sub-regions of the grids. Main Outcome Measures Age-related changes in MCT, CVV, CSV, and CVI using 6×6 mm and 12×12 mm SS-OCT scans. Results The automated choroid segmentations were validated against manual segmentations, and MCT measurements were shown to be in good agreement (P Conclusions While MCT, CVV, and CSV decrease with age, the CVI and CSVR remain constant in all regions with age. Ongoing studies are using these automated algorithms on SS-OCT structural datasets to investigate the diagnostic usefulness of these choroidal parameters in a myriad of ocular and systemic diseases.