ObjectiveTo observe the changes of glaucoma optic nerve head (ONH) parameters and macular ganglion cell complex (GCC) structure in preperimetric glaucoma (PPG) patients. Methods Eighteen PPG patients (18 eyes, PPG group), 22 primary open-angle glaucoma (POAG) patients (22 eyes, POAG group), and 20 patients (20 eyes) with physiologic large optic cup (physiological big optic cup group) were included in this study. Seventeen healthy volunteers (17 eyes) were the normal control. The optic nerve head and macular was scanned by fourier-domain optic coherence tomography (FD-OCT) for all subjects. The following 15 parameters, including nerve fiber layer thickness (RNFL), the optic disk rim volume (RV), optic nerve head volume (NHV), optic disc area (ODA), rim area (RA), cup volume (CV), cup/disc area ratio (CDAR), vertical cup/disc ratio (VCDR), horizontal cup/disc ratio (HCDR) and optic cup area (CA), macular GCC, superior GCC, inferior GCC thickness, focal loss of volume (FLV) and global loss of volume (GLV), were measured at 10 different quadrants. The relationship between macular GCC thickness or optic disc RNFL thickness and RA was analyzed by simple linear regression analysis. ResultsThe RNFL thickness of PPG patients was (99.29±19.93) μm (superior quadrant), (97.29±22.86) μm (inferior), (114.61±15.64) μm (superior temporal, ST), (119.22±26.19) μm (inferior temporal, IT), (116.11±39.32) μm (superior nasal, SN), (111.33±37.65) μm (inferior nasal, IN), (77.56±17.22) μm (temporal upper, TU), (76.78±10.34) μm (temporal lower, TL), (88.94± 42.54) μm (nasal upper, NU), and (82.33±43.83) μm (nasal lower, NL) respectively, which was thinner than normal control group and physiologic large cup group, but thicker than POAG patients. Compared to normal controls and physiologic large cup patients, PPG patients also had 4 parameters reduced (RV, NHV, ODA and RA), and 5 parameters increased (CV, CDAR, VCDR, HCDR and CA), the differences are statistically significant (P < 0.05). However, these parameters were similar to POAG patients (P > 0.05). For macular GCC parameters, PPG patients also had 3 parameters reduced (average GCC, superior and inferior GCC thickness), and 2 parameters increased (GLV and FLV) compared to normal control group and physiologic large cup patients (P < 0.05). However, these parameters were similar to POAG patients (P > 0.05).Simple linear regression analysis showed that, with the GCC macular thinning, reducing the number of ganglion cells reduced, optic disc RNFL thickness became thinner (regression coefficient=1.25, P=0.00) and RV reduced (regression coefficient=0.037, P=0.00). ConclusionsPPG patients and normal control had a similar distribution of optic disc RNFL. Five parameters (RV, NHV, ODA, RA, macular GCC thickness) were less than normal control and physiological big optic cup group, but had no significant differences compared with POAG group.