Evaluation of Layer-by-Layer Segmented Ganglion Cell Complex Thickness for Detecting Early Glaucoma According to Different Macular Grids.

PURPOSE

To investigate the diagnostic performance of layer-by-layer segmented macular ganglion cell complex (GCC) thickness for detecting early glaucoma using spectral-domain optical coherence tomography (SD-OCT) with different macular grids.

MATERIALS AND METHODS

Sixty-two early-stage open-angle glaucoma patients and 70 healthy subjects were enrolled in this study. The SD-OCT with automated segmentation was used to obtain macular scans with different grids of "1, 2, and 3 mm"; "1, 2.22, and 3.45 mm"; and "1, 3, and 6 mm" diameters. The separate thicknesses of the macular retinal nerve fiber layer (mRNFL), ganglion cell layer (GCL), inner plexiform layer (IPL), ganglion cell-inner plexiform layer (GCIPL: GCL+IPL), and GCC (RNFL+GCL+IPL) were measured in each grid. The areas under the receiver operating characteristics were used to compare their specific diagnostic abilities.

RESULTS

In all macular grid diameters, the mRNFL, GCL, and IPL thicknesses, except mRNFL in the 1 to 2 mm macular grid, were significantly thinner in patients with early glaucoma than in healthy subjects. The GCC and GCL in the 3 to 6 mm macular grid diameters were best able to discriminate between early glaucoma and normal groups. When including quadrant parameters in the 3 to 6 mm macular grid diameter, the temporal GCL had the largest areas under the curve of receiver operating characteristics (0.906).

CONCLUSIONS

Large macular grids have generally high discriminating power for the diagnosis of early glaucoma by SD-OCT. The GCL or GCC thickness in 3 to 6 mm macular grid could be useful for the identification of early glaucomatous structural loss.