The Pattern of Retinal Nerve Fiber Layer and Macular Ganglion Cell-Inner Plexiform Layer Thickness Changes in Glaucoma

BACKGROUND/AIMS To investigate the patterns of retinal ganglion cell damage at different stages of glaucoma, using the circumpapillary retinal nerve fiber layer (RNFL) and macula ganglion cell-inner plexiform layer (GCIPL) thicknesses. METHODS In 296 eyes of 296 glaucoma patients and 55 eyes of 55 healthy controls, the correlations of mean deviation (MD) with the superior and inferior quadrant RNFL/GCIPL thickness (defined as the average of three superior and inferior sectors, resp.) were analyzed. RESULTS In early to moderate glaucoma, most of the RNFL/GCIPL thicknesses had significant positive correlations with the MD. In advanced glaucoma, the superior GCIPL thickness showed the highest correlation with MD (r = 0.495), followed by the superior RNFL (r = 0.452) (all; P < 0.05). The correlation coefficient of the inferior RNFL thickness with MD (r < 0.471) was significantly stronger in early to moderate glaucoma compared to that in advanced glaucoma (r = 0.192; P < 0.001). In contrast, the correlations of the superior GCIPL thickness with MD (r = 0.452) in advanced glaucoma was significantly stronger compared to that in early to moderate glaucoma (r = 0.159; P < 0.001). CONCLUSIONS The most preserved region in advanced glaucoma appears to be the superior macular GCIPL, whereas the most vulnerable region for initial glaucoma is the inferior RNFL around the optic disc.