Enhanced Depth Imaging Optical Coherence Tomography in Uveitis: An Intravisit and Interobserver Reproducibility Study

Purpose To determine the intravisit and interobserver reproducibility of subfoveal choroidal thickness (SFCT) measurements in patients with noninfectious uveitis. Design Reliability analysis. Methods Two consecutive enhanced depth imaging optical coherence tomography (EDI-OCT) scans were obtained at a single clinic visit for 97 uveitic eyes from patients ≥16 years of age with noninfectious anterior (n = 10), intermediate (n = 11), posterior (n = 26), and panuveitis (n = 13) at the National Eye Institute. SFCT was manually measured by 2 ophthalmologists using manufacturer's software. Intravisit and interobserver reproducibility of SFCT measurements were assessed by using the Bland-Altman method to determine the estimate of bias (mean difference in SFCT measurements), 95% limits of agreement, and coefficients of repeatability. The reproducibility of these measurements was also compared between groups by anatomic location and clinical activity. Results Of 97 eyes, 65 (67.0%) were clinically quiet, 18 (18.6%) were minimally active, and 14 (14.4%) were active at the time the scans were obtained. Manual SFCT measurements were reproducible within 32.4 ± 3.8 μm between sessions for the same observer and 51.4 ± 8.5 μm between observers for the same session. Coefficients of repeatability did not differ significantly by anatomic location or disease activity. Conclusions Manual SFCT measurements obtained by EDI-OCT are reproducible in uveitis patients, with coefficients of repeatability that are nearly comparable to those published for normal eyes. This study provides guidance for using manual SFCT measurements in clinical practice, but further studies are still needed to determine their utility in clinical trials.