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.