Topographic Correlation Between Juxtapapillary Choroidal Thickness and Microstructure of Parapapillary Atrophy

To investigate the topographic relationship between the juxtapapillary choroidal thickness (JPCT) and the microstructure of parapapillary atrophy (PPA) in primary open-angle glaucoma (POAG).

Cross-sectional observational study.

A total of 126 eyes (76 POAG eyes and 50 healthy control eyes) of 126 subjects with β-zone PPA.

Optic nerve heads were imaged using spectral-domain optical coherence tomography (OCT) to measure the JPCT. On the basis of the extent of Bruch's membrane (BM) within the β-zone PPA, the β-zone PPA was divided into PPA with intact BM (PPA+BM) and PPA devoid of BM (PPA-BM). The width of each type of PPA, together with the JPCT, was measured at 12 meridians on 6 radial B-scan images.

Topographic correlation between the width of PPA+BM and PPA-BM and the JPCT and factors associated with the JPCT.

The JPCT was significantly smaller in the POAG group than in the healthy control group in the inferotemporal region (6, 7, 8, and 9 o'clock; all P ≤ 0.0002). The PPA+BM width was larger in the POAG group in the inferotemporal region (6, 7, 8, and 9 o'clock; P ≤ 0.004), whereas the PPA-BM width did not show significant differences between groups in any of the locations. Regression analysis revealed a significant influence of older age (P = 0.002) in the healthy control group and a significant influence of older age (P < 0.001) and a larger PPA+BM width (P = 0.006) on the smaller JPCT in the POAG group.

The JPCT was topographically correlated with the PPA+BM width but not with the PPA-BM width. Juxtapapillary choroidal atrophy and the formation of PPA+BM, but not the formation of PPA-BM, may share a common pathogenic mechanism in glaucomatous optic nerve damage.