Spectral-domain optical coherence tomography of β-zone peripapillary atrophy: influence of myopia and glaucoma.

PURPOSE: To investigate the influence of glaucoma and myopia on the cross-sectional configuration of the β-zone of peripapillary atrophy (PPA-β) using spectral-domain optical coherence tomography (SD-OCT).
METHODS: Cross-sectional B-scan images of PPA-β obtained with SD-OCT were evaluated in 100 eyes of 100 consecutive patients with POAG, regardless of intraocular pressure level, and in 100 eyes of 100 normal subjects. PPA bed configurations were classified, and associated factors were studied with multivariate analysis.
RESULTS: In 147 eyes with PPA-β (84 POAG and 63 normal eyes; P = 0.0012), the PPA bed was composed of straight (14 POAG and 27 normal eyes) or downward-curved (19 and 8 eyes) Bruch's membrane (BM) or of a downward-bending slope lacking BM (BM defect; 51 and 28 eyes). Multivariate analysis revealed that absence of POAG (odds ratio [OR], 0.36; P = 0.034) and less myopic refractive error (OR, 1.43; P = 0.009) were significantly associated with straight-BM-type, presence of POAG (OR, 5.74; P = 0.008) and less myopic refractive error (OR, 3.02; P < 0.001) with curved-BM-type, and myopic refractive error (OR, 0.34; P < 0.001) with BM-defect-type. Within the PPA-β region, all retinal layers except for the nerve fiber layer frequently disappeared before reaching the disc edge, showing no significant intergroup difference (P > 0.05) between POAG and normal eyes.
CONCLUSIONS: PPA bed configurations detected by SD-OCT were classified into three types. The lack of BM on the PPA bed was closely associated with myopia. The downward-curved appearance of BM may be related to the anatomic changes associated with glaucoma.