β zone Peripapillary Atrophy as a Predictor of Glaucomatous Structural and Functional Progression

Abstract

Purpose : The presence of β zone peripapillary atrophy (PPA) has been associated with glaucoma. We performed a retrospective longitudinal study to evaluate β zone PPA area as a predictor for glaucomatous structural and functional progression.

Methods : Subjects with glaucoma and ≥4 visits were included. Subjects had Humphrey visual field (Zeiss, Dublin, CA) testing, spectral-domain OCT (Cirrus HD-OCT; Zeiss) optic nerve head (ONH) and macula scans. β zone PPA was manually delineated on the baseline en face ONH scan as the area contiguous with the optic disc with the presence of hyper- and hyporeflectivity. Mixed effects linear models accounting for intra-subject correlation, follow-up time, scan’s signal strength and ethnicity, were performed to determine if baseline PPA area was associated with glaucoma severity. Subsequent models incorporating the interaction term between time and baseline PPA area were performed to determine if baseline PPA area affected the rate of change in parameters of glaucoma over time.

Results : 81 eyes (56 subjects) aged 62.8±14.1 years with an average follow-up time 3.9±1.3 years were analyzed. PPA was significantly associated with mean deviation (MD), visual field index (VFI), and inferior retinal nerve fiber layer (RNFL), (p=0.033, 0.038, and 0.034, respectively), but not with average RNFL, or macular ganglion cell inner plexiform layer (GCIPL) global and sectoral measurements and ONH parameters. No significant association was detected between β zone PPA area and the rate of progression for any parameter except for VFI (p =0.035).

Conclusions : Although baseline β zone PPA area is associated with some indicators of glaucoma severity, it is not a significant predictor of the rate of glaucomatous progression (except for VFI).

This is a 2020 ARVO Annual Meeting abstract.