REPEATABILITY OF CHOROIDAL THICKNESS MEASUREMENTS ASSESSED WITH SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY IN HEALTHY AND DIABETIC INDIVIDUALS

Purpose: To assess the intrasession repeatability of choroidal thickness measurements obtained using swept-source optical coherence tomography in Type 2 diabetic (T2D) patients and healthy controls. Methods: This was a single-center, prospective, observational, cross-sectional study with consecutive inclusion of 33 healthy subjects and 43 T2D patients. Subjects underwent three consecutive swept-source optical coherence tomography scans in a single session. After automatic delineation of the choroid, subfoveal choroidal thickness, and thickness at 500-mu m intervals up to 2,500 mu m nasal and temporal from the fovea were measured using the software caliper by the same operator. Intraclass correlation coefficients (ICCs), coefficients of variation, and test-retest variability were calculated. Results: Mean subfoveal choroidal thickness in healthy subjects and in T2D patients was 229.97 +/- 79.9 and 192.67 +/- 74.3 mu m, respectively (P = 0.013). All intrasession intraclass correlation coefficients were higher than 0.95 and 0.99, respectively. Coefficients of variations were less than 4.4% and 1.8%, respectively. Test-retest variability ranged from 0.76 mu m to 11.12 mu m and 0.64 mu m to 6.29 mu m, respectively. No significant differences were found in the intrasession repeatability of any choroidal measurement between healthy subjects and T2D patients. Conclusion: Swept-source optical coherence tomography provided excellent intrasession repeatability of choroidal thickness measurements in healthy subjects and T2D patients.