Can We Predict the Location of Glaucoma Progression Based on the Location of the Largest Peripapillary Atrophy?

Abstract

Purpose : β zone peripapillary atrophy (PPA) has been associated with glaucoma and the location of the largest β zone PPA is spatially associated with the region of fastest glaucomatous visual field progression. We performed a retrospective longitudinal study to evaluate the location of the largest β zone PPA as a predictor for glaucomatous structural progression in the same region.

Methods : Subjects with glaucoma and ≥4 visits had spectral-domain OCT (Cirrus HD-OCT; Zeiss) optic nerve head (ONH) scans. β zone PPA was defined as the area contiguous with the optic disc with the presence of hyper- and hyporeflectivity on the baseline en face ONH scan, from which the quadrant containing the largest diameter of β zone PPA was determined. The location of trend progression was independently defined as the quadrant where linear regression of retinal nerve fiber layer (RNFL) thickness measurements first reached significance. Location of event progression was defined as the quadrant containing the largest area marked as progression by the guided progression analysis (GPA) reports of the device. Cohen’s kappa coefficient was used to determine the agreement between the locations of the largest β zone PPA and structural progression.

Results : 78 eyes (54 subjects) aged 64.7±10.4 years with an average follow-up time of 4.2±1.4 years were analyzed. 31 eyes (39.7%) had event progression and 22 (28.2%) eyes had trend progression. There was no statistically significant agreement between the quadrant of largest β zone PPA and the quadrant of trend progression (kappa: -0.01 – 0.2; p >0.05) nor the quadrant of event progression (kappa: -0.033 – 0.185; p>0.05). Similarly, there was a slight, but non-significant agreement between the quadrant of largest β zone PPA and the quadrant of event or trend progression in the subgroup of only those eyes that progressed (kappa: 0.14; p=0.12).

Conclusions : The quadrant of largest β zone PPA is not predictive of the quadrant of structural progression. However, further studies are needed to examine the effect of longitudinal changes of PPA on structural progression.

This is a 2020 Imaging in the Eye Conference abstract.