This was a retrospective study that used cross-sectional data from the Duke Glaucoma Registry, a database of electronic medical and research records at the Vision, Imaging, and Performance Laboratory at Duke University. The Duke Health Institutional Review Board approved this study, and a waiver of informed consent was granted due to the retrospective nature of this work. All methods adhered to the tenets of the Declaration of Helsinki for research involving human subjects and the study was conducted in accordance with regulations of the Health Insurance Portability and Accountability Act.
The visual field tests were performed using SAP with the 24-2 Swedish Interactive Threshold Algorithm (Carl Zeiss Meditec, Inc., Dublin, CA) protocol. Unreliable tests with more than 33% fixation losses or 15% false-positive errors were excluded. RNFL thickness measurements were obtained from peripapillary circle scans, acquired using the Spectralis SDOCT (Heidelberg Engineering, GmbH, Dossenheim, Germany). According to manufacturer recommendations, tests with a quality score lower than 15 were excluded. The fundus photos present in the database were acquired from two different cameras: Nidek 3DX (Nidek, Japan) and Visupac (Carl Zeiss Meditec, Inc., Dublin, CA). The image was retained if the optic disc was entirely visible in the photo, and if no artifacts were present.
The visual field tests were performed using SAP with the 24-2 Swedish Interactive Threshold Algorithm (Carl Zeiss Meditec, Inc., Dublin, CA) protocol. Unreliable tests with more than 33% fixation losses or 15% false-positive errors were excluded. RNFL thickness measurements were obtained from peripapillary circle scans, acquired using the Spectralis SDOCT (Heidelberg Engineering, GmbH, Dossenheim, Germany). According to manufacturer recommendations, tests with a quality score lower than 15 were excluded. The fundus photos present in the database were acquired from two different cameras: Nidek 3DX (Nidek, Japan) and Visupac (Carl Zeiss Meditec, Inc., Dublin, CA). The image was retained if the optic disc was entirely visible in the photo, and if no artifacts were present.