Topographic Correlation Between Juxtapapillary Choroidal Thickness and Microstructure of Parapapillary Atrophy.

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

DESIGN: Cross-sectional observational study.

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

METHODS: 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.

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

RESULTS: 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.

CONCLUSIONS: 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.