Clinical Validity of Macular Ganglion Cell Complex by Spectral Domain-Optical Coherence Tomography in Advanced Glaucoma

Purpose: To evaluate the repeatability and diagnostic power of macular ganglion cell complex (mGCC) thickness and peripapillary retinal nerve fiber layer (pRNFL) thickness using a spectral domain-optical coherence tomography in advanced glaucoma. Patients and Methods: Forty advanced glaucoma patients were enrolled. Patients were divided into 2 groups of 20 patients each, according to the MD between -20 and -10 dB, and < -20 dB. The thickness of mGCC and pRNFL were measured with spectral domain-optical coherence tomography in both the groups. The repeatability of each parameter was assessed in both the groups, and the diagnostic power of each parameter was compared with the normal controls. Results: Comparison of diagnostic power between the pRNFL and mGCC parameters revealed that the area under the receiver operating characteristic curve was not significantly different in patients with advanced glaucoma. The repeatability of pRNFL parameters was similar, irrespective of the severity of glaucoma. However, the repeatability of mGCC parameters became lower as the severity increased in patients with advanced glaucoma. Conclusions: In advanced glaucoma, the measurement of mGCC thickness has similar diagnostic power as the measurement of pRNFL thickness. However, the measurement of mGCC thickness showed a lower repeatability as MD decreased.