Comparison of the ganglion cell complex and retinal nerve fibre layer measurements using Fourier domain optical coherence tomography to detect ganglion cell loss in non-arteritic anterior ischaemic optic neuropathy

Objective To evaluate the diagnostic ability of macular ganglion cell complex (GCC) and peripapillary nerve fibre layer (NFL) measurements to detect ganglion cell loss (GCL) in patients with non-arteritic anterior ischaemic optic neuropathy (NAION), at the chronic stage. Methods This study included 10 eyes from 10 patients with NAION and 15 eyes from 15 age-matched healthy subjects. The measurements included the GCC thicknesses as average, superior and inferior, the GCC parameters as focal loss volume (FLV) and global loss volume (GLV), the NFL thicknesses as average, superior hemisphere and inferior hemisphere, and the disc parameters as rim area and rim volume. The curves for the area under the receiver operator characteristic (AUROC) were generated to assess the ability of each parameter to detect GCL. Results The patient group had significantly lower GCC thicknesses than the control group (p<0.001, <0.001 and 0.004, for the GCC average, superior and inferior, respectively), and also significantly higher FLV and GLV measurements (p<0.001). The NFL thicknesses were found to be significantly lower in the patient group than the control subjects (p<0.001). Among all the parameters, the FLV and the GLV had the highest levels of AUROC values (1.000, 0.990, respectively). Conclusions The FLV and the GLV showed the strongest abilities to detect GCL in patients with NAION. In addition, peripapillary NFL thickness was comparable to macular GCC thickness in detecting GCL. Therefore, macular GCC scans may provide a good alternative or a complementary practice to NFL scans in the detection of GCL in patients with NAION.