AIM:To evaluate the extent of damage caused by moderate and severe glaucoma on ganglion cell inner plexiform layer(GCIPL)and to evaluate the diagnostic performance of this layer compared to the peripapillary retinal nerve fiber layer(PRNFL). This was performed by comparing their area under the curve(AUC)sensitivity and specificity.

METHODS:This study is a prospective study. Two hundred ten eyes(54 eyes of 30 moderate glaucoma subjects, 59 eyes of 34 severe glaucoma subjects and 97 eyes of 50 normal subjects)were enrolled in this study. Patients underwent complete ophthalmic examination, visual field(VF)examination and also 3D optical coherence tomography(OCT)of the disc and 3D vertical(V)OCT of the macula were performed. The GCIPL and PRNFL AUC, sensitivity and specificity were performed and compared.

RESULTS:A significantly thinner superior, inferior and total GCIPL and PRNFL thickness in moderate and severe glaucoma groups was detected(all P<0.001). In moderate glaucoma, GCIPL showed higher sensitivity and specificity than PRNFL(only the superior half shows equal sensitivity). As regard severe glaucoma the total, superior and inferior sensitivities of the GCIPL were lower than the PRNFL. The total GCIPL specificity was lower than the PRNFL. The superior GCIPL specificity was higher than the PRNFL. The lower GCIPL specificity was equal to that of the PRNFL.

CONCLUSION:The ability of the macular GC/IPL parameters to discriminate moderate and severe glaucoma is high and comparable to that of the PRNFL. A combination of both in the baseline evaluation is optimal and provides more accurate assessment of the extent of damage.