Comparison of Patterns of Structural Progression in Primary Open-Angle Glaucoma and Pseudoexfoliation Glaucoma

Abstract

Precis: Primary open-angle glaucoma and pseudoexfoliation glaucoma showed different progression patterns of retinal nerve fiber layer and ganglion cell-inner plexiform layer thinning in OCT guided progression analysis. Purpose: To compare the patterns of progression of retinal nerve fiber layer (RNFL) and macular ganglion cell-inner plexiform layer (GCIPL) thinning by guided progression analysis (GPA) of optical coherence tomography (OCT) in primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXG). Methods: The progression of RNFL and GCIPL thinning was assessed by GPA of Cirrus HD-OCT (Carl Zeiss Meditec, Dublin, CA, USA). By overlaying the acquired images of the RNFL and GCIPL thickness-change maps, the topographic patterns of progressive RNFL and GCIPL thinning were evaluated. The rates of progression of RNFL and GCIPL thinning were analyzed and compared between patients with POAG and those with PXG. Results: Of the 248 eyes of 248 patients with POAG (175 eyes of 175 patients) or PXG (73 eyes of 73 patients) enrolled, 156 POAG eyes and 48 PXG eyes were included. Progressive RNFL thinning was significantly more common in PXG than in POAG (P=0.005). According to the RNFL progression-frequency maps, progression appeared mainly in the superotemporal and inferotemporal areas in POAG, whereas it had invaded more into the temporal area in PXG. According to the GCIPL maps, progression was most common in the inferotemporal area in both POAG and PXG. The average progression rate of GCIPL thinning was faster in PXG than in POAG (P=0.013), and when analyzed in 2 halves (superior/inferior), the progression rate of the inferior half was faster in PXG than in POAG (P=0.011). Conclusion: OCT GPA showed progression patterns of RNFL and GCIPL thinning in POAG and PXG. Understanding the specific patterns of progressive RNFL and GCIPL thinning according to glaucoma type may prove helpful to glaucoma-patient treatment and monitoring.