Effects of Optic Nerve Head Structures on Retinal Nerve Fiber Layer Defects in Primary Open Angle Glaucoma Eyes: Analyses Using Retinal Optical Texture Analysis.

Abstract

To elucidate associations between optic nerve head (ONH) structures and the retinal nerve fiber layer optical texture analysis (ROTA)-detected retinal nerve fiber layer defects (RNFLDs) in primary open angle glaucoma (POAG) eyes. Prospective cross-sectional observational study. This study enrolled 136 eyes of 109 POAG patients. All participants underwent comprehensive ophthalmologic examinations including standard automated perimetry and swept-source optical coherence tomography (SS-OCT). Two independent graders assessed ROTA images for the presence, location, and width of RNFLDs. Multivariable linear mixed effects model was used to investigate factors independently associated with ROTA-detected RNFLDs. Explanatory variables were systemic and ocular factors such as age, axial length (AXL), SS-OCT-derived ONH structural parameters such as Bruch membrane opening-centered circumpapillary retinal nerve fiber layer thickness (cpRNFLT) and gamma zone area, and average visual field sensitivity (1/Lambert) (VFS_average). Width and number of RNFLDs. RNFLD detection rates by ROTA were 86.8% overall, 69.0% and 94.7% in the early and moderate stages of POAG eyes, and 86.5% and 87.2% in the highly myopic (AXL >26.0 mm) and non-highly myopic eyes, respectively. Summed width of RNFLD per eye was positively correlated with gamma-zone area (P = .0007) and negatively correlated with age, cpRNFLT, and VFS_average (P = .0111, .0001, .0124), whereas the number of RNFLDs per eye correlated negatively with age, cpRNFLT, and VFS_average (P = .0153, .0029, .0007). The ROTA-detected extent of axonal damage was associated with ONH structural change represented by gamma zone area in POAG eyes after adjustment for other possible confounding factors.