Macular choroidal thickness: evaluation of variability among measurements and assessment of predictive value of glaucomatous visual field damage

Introduction: To investigate the relationship between the choroidal circulation and glaucoma, assessing macular choroidal thickness (MCT) as a predictive value of glaucomatous visual field damage. Methods: Twenty primary open-angle glaucoma patients were recruited. Patients underwent two SS-OCTs scans: one with DRI OCT (Topcon) and the other with PLEX Elite 9000 (Zeiss). Standard OCT parameters were acquired by DRI OCT, while MCT was manually measured in 5 points on Plex ELITE 9000 images. The relationship among MCT, standard OCT parameters and visual field indices were evaluated. Pearson's r correlation was calculated to evaluate these relationships. Reproducibility of measurements was analyzed. Results: MCT measurements showed a good intra- and inter-observer repeatability. A negative correlation appeared between MCT and body mass index (BMI) (r = -0.518, p=0.023). Mean deviation showed a statistically significant correlation with MCT measured at sub-foveal and at 1000 µm nasally (r = 0.50, p=0.03 and r = 0.52, p=0.023). A correlation was found between the two MCT (Zeiss vs Topcon) measurements and between MCT and peripapillary choroidal thickness (r = 0.944 and r = 0.740, p<0.001, respectively). Conclusions: A good intra- and inter-observer reproducibility was found. MCT showed a weak predictive value of glaucomatous visual field damage. A significant correlation was found between MCT and BMI.