Intrapapillary Damage and Its Functional Association in Normal Tension Glaucomatous Eyes With and Without Peripapillary Intrachoroidal Cavitation

Purpose: To compare optic nerve head (ONH) structure, visual field (VF) characteristics, and structure-function relationships including intrapapillary structural changes between normal tension glaucomatous (NTG) eyes with and without peripapillary intrachoroidal cavitation (PICC). Methods: This cross-sectional observational study enrolled 94 NTG eyes with PICC (NTG + PICC), 188 NTG eyes without PICC (NTG - PICC) matched for age, axial length, and VF severity, and 30 healthy eyes. Bruch's membrane opening (BMO) and scleral flange opening (SFO) were identified on ONH-centered OCT images. SFO-minimum rim width (SFO-MRW), the shortest distance between the SFO and prelaminar tissue surface, was used to evaluate focal intrapapillary tissue thinning. ONH structure, sectoral Humphrey 24-2 VF sensitivity (VFS), circumpapillary retinal nerve fiber layer thickness and SFO-MRW were compared among groups. Multivariable linear regression models were applied to identify factors associated with sectoral VFS. Results: NTG + PICC showed significantly larger BMO and SFO areas and greater SFO/BMO offset magnitude compared with NTG - PICC and healthy eyes (all P < 0.001). Despite comparable circumpapillary retinal nerve fiber layer thickness and VF severity, NTG + PICC had worse temporal VFS (P = 0.006) and a thinner temporal SFO-MRW (P = 0.002). In the best-fit multivariable model, worse temporal VFS in NTG + PICC was significantly associated with thinner SFO-MRW, larger BMO area and smaller SFO area (all P < 0.05). Conclusions: NTG + PICC exhibited more pronounced myopia-associated ONH remodeling and temporal intrapapillary thinning compared with NTG - PICC, and these changes were associated with worse central VFS. These findings suggest that focal intrapapillary thinning at the peripapillary scleral edge is a potential structural biomarker that complements conventional RNFL-based evaluation in eyes with highly myopic changes.