Comparison of glaucoma diagnostic ability of ganglion cell-inner plexiform layer according to the range around the fovea

BACKGROUND: To compare the glaucoma diagnostic ability of the ganglion cell-inner plexiform layer (GCIPL) thickness depending on the range around the fovea using wide-angle, swept-source optical coherence tomography (SS-OCT). METHODS: We compared the glaucoma diagnostic utility of GCIPL parameters across multiple regions while centered on the fovea. In a wide-angle scan, the GCIPL for each 1-mm(2) grid square of a 12 × 9 mm(2) scan resulted in 108 data points. With respect to the range of the GCIPL measurements around the macula, the wide-angle scan images were classified into three zones. Zone 1 was defined as a narrow area; zone 2 was defined as a mid-sized area; and zone 3 was defined as a wide area. We recorded the quadrant GCIPL thickness, average, and minimum quadrant GCIPL within each zone. The areas under the receiver operating characteristic (AUROCs) curves were calculated to evaluate the glaucoma diagnostic utility. RESULTS: Sixty-one eyes with glaucoma and 59 normal eyes were assessed. The minimum and average GCIPL measurements in zones 1–3 in eyes with glaucoma were significantly lower than those in normal eyes (P < 0.001). The AUROCs for the minimum and inferotemporal GCIPL in zone 1 and the inferotemporal GCIPL thickness in zone 2 were greater than 0.9 (0.945, 0.931, and 0.918, respectively). CONCLUSIONS: Wide-angle scanning using SS-OCT will contribute to improvements in the detection of glaucomatous damage. The minimum and inferotemporal GCIPL in zone 1 may be more useful for detecting glaucoma than those in the conventional area.