Relationship Between Juxtapapillary Choroidal Volume and Beta-Zone Parapapillary Atrophy in Eyes With and Without Primary Open-Angle Glaucoma.

PURPOSE To evaluate whether quantity of choroidal tissue directly adjacent to the optic nerve differs between eyes with and without glaucoma and whether beta-zone parapapillary atrophy influences this relationship. DESIGN Prospective cohort study. METHODS Subjects were enrolled in a longitudinal, observational study at our institution. We studied 1 eye of 63 primary open-angle glaucoma (POAG), 30 ocular hypertension (OH), and 48 control subjects. Using optical coherence tomography enhanced depth imaging, we acquired 12 radial scans centered on the optic nerve head with 15 degrees of separation between scans. After images were enhanced, segmented, and corrected for ocular magnification, juxtapapillary choroidal volumetric parameters were calculated using raw thickness measurements and standard interpolation techniques. Juxtapapillary choroidal volume was then compared by diagnosis and by beta-zone parapapillary atrophy status. RESULTS Total juxtapapillary choroidal volume was significantly reduced in POAG vs OH and control eyes (1.057 vs 1.228 vs 1.255 μL, P = .04) and it was reduced in eyes with vs without beta-zone parapapillary atrophy (1.076 μL, n = 80 vs 1.306 μL, n = 61, P < .001). Juxtapapillary choroidal volume did not differ between POAG, OH, and control eyes when beta-zone parapapillary atrophy was absent, but juxtapapillary choroidal volume was significantly reduced in POAG vs control eyes when beta-zone parapapillary atrophy was present (0.957 vs 1.196 μL, P = .02). Furthermore, POAG eyes with beta-zone parapapillary atrophy had substantially lower juxtapapillary choroidal volume compared to POAG eyes without beta-zone parapapillary atrophy (0.957 vs 1.356 μL, P < .001). CONCLUSIONS The volume of choroid adjacent to the optic nerve was significantly reduced in POAG eyes when beta-zone parapapillary atrophy was present, suggesting that beta-zone parapapillary atrophy may be a biomarker for juxtapapillary choroidal atrophy and associated vascular compromise in POAG.