Correlation of peripapillary retinal nerve fiber layer and macular ganglion cell–inner plexiform layer in early to moderate glaucoma using the Cirrus® widefield analysis (PanoMap®)

Abstract

Abstract Purpose: To evaluate and correlate the structural changes between peripapillary retinal nerve fiber layer (RNFL) and macular ganglion cell layer (GCL) + inner plexiform layer (IPL) in different stages of glaucoma using PanoMap® optical coherence tomography (OCT). Design: Retrospective observational study. Methods: Glaucoma diagnostic test data were collected from early to moderate open-angle glaucoma patients. The average and minimum GCL + IPL thickness, sectoral GCL + IPL thickness, and the average and sectoral RNFL thickness were correlated with the different glaucoma stages. Results: This study included 157 eyes from 157 glaucoma patients. Patients were grouped into pre-perimetric, early, and moderate glaucoma. The mean average RNFL thickness, RNFL thickness per sector, average GCL + IPL thickness, and minimum GCL + IPL thickness were different between the three groups (P < 0.001), except for the nasal sector (P = 0.643).The mean GCL + IPL thickness in all six sectors showed differences between the groups (P < 0.001), except the superonasal sector (P < 0.002).The inferior GCL + IPL sector is the thinnest, followed by the inferotemporal sector. There was a strong correlation between the mean average RNFL and the average GCL + IPL thickness in the pre-perimetric group (r = 0.4963, P < 0.001) and the moderate group (r = 0.6534, P < 0.001).The early glaucoma group did not show significant correlation (r = 0.2963, P = 0.0536). Conclusion: Peripapillary RNFL and macular GCL + IPL thinning was evident in different stages of glaucoma, with more thinning observed with increasing glaucoma severity. The peripapillary RNFL and macular GCL + IPL average thickness values were highly correlated in the pre-perimetric and moderate stages of glaucoma.