Effects of Deep Optic Nerve Head Structures on Bruch's Membrane Opening- Minimum Rim Width and Peripapillary Retinal Nerve Fiber Layer.

PURPOSE: To explore the effects of deep optic nerve head (ONH) structures on Bruch's membrane opening (BMO)-minimum rim width (MRW) and peripapillary retinal nerve fiber layer thickness (pRNFLT) in healthy eyes. DESIGN: Prospective cross-sectional study. METHODS: Two hundred five healthy eyes of 141 subjects (mean ± standard deviation of age and axial length (AXL): 46.9 ± 10.0 years and 24.79 ± 1.15 mm) were enrolled. Best fit multivariable linear mixed models identified factors associated with BMO-MRW and pRNFLT. Explanatory variables included age, gender, AXL, BMO and anterior scleral canal opening (ASCO) area and ovality, magnitude of BMO and ASCO shift, peripapillary choroidal thickness, lamina cribrosa (LC) parameters, prelaminar thickness, and peripapillary scleral (PPS) angle. RESULTS: Thinner BMO-MRW was associated with older age, smaller ASCO/BMO offset magnitude, larger BMO area, thinner prelaminar thickness, deeper LC, and thinner pRNFLT (P = .011, <.001, .004, <.001, <.001, <.001 respectively). Thinner pRNFLT was associated with shorter AXL, smaller ASCO area, a more posteriorly bowed PPS, shallower LC and thinner BMO-MRW. (P = .030, .002, .035, .012, <.001 respectively) CONCLUSIONS: BMO-MRW and pRNFLT were influenced by several deep ONH structures such as BMO and ASCO position shift, BMO or ASCO area, prelaminar thickness, PPS bowing and LC depth in addition to patient characteristics such as age and AXL. The degree and/or direction of associations varied between deep ONH structures and BMO-MRW or pRNFLT. Despite both BMO-MRW and pRNFLT being surrogate parameters for RGC loss, a complex relationship with ONH deep-layer morphology was indicated.

Association of Bergmeister Papilla and Deep Optic Nerve Head Structures With Prelaminar Schisis of Normal and Glaucomatous Eyes.

PURPOSE: To investigate factors associated with the severity of prelaminar schisis (PLS) in heathy subjects and glaucoma patients. DESIGN: Prospective cross-sectional study. METHODS: A total of 217 eyes of 217 subjects (110 normal eyes and 107 open angle glaucoma eyes) were studied. Frequency and severity of PLS were compared between normal and glaucomatous eyes. Multivariate logistic models were used to assess factors associated with the severity of PLS. Factors considered were age, axial length, glaucomatous damage indices, Bruch membrane opening (BMO) and anterior scleral canal opening parameters, tractional forces (posterior vitreous staging and presence of Bergmeister papilla), circumpapillary choroidal thickness, lamina cribrosa (LC) parameters, and peripapillary scleral (PPS) angle. RESULTS: The frequency of PLS was 70.9% in normal eyes and 72.0% in glaucomatous eyes. There was no difference in frequency and severity between the groups. The presence of Bergmeister papilla was the strongest predictor of a more severe PLS in both normal and glaucomatous eyes (odds ratio [OR] + 9.78, 12.5; both P < .001). A larger PPS angle in normal eyes (OR = 1.19; P = .003) and a larger BMO area and a deeper LC depth in glaucomatous eyes (OR = 1.08, 1.05; both P = .038) were associated with severity of PLS. CONCLUSIONS: The severity of PLS was strongly associated with the presence of Bergmeister papilla, suggesting a traction-related phenomenon. Correlation of PLS severity with larger BMO area and deeper LC depth, which are optic nerve head structures associated with glaucoma, suggested its possible relationship with glaucomatous damage.

Deep Optic Nerve Head Structures Associated With Increasing Axial Length in Healthy Myopic Eyes of Moderate Axial Length.

PURPOSE: To elucidate which swept-source optical coherence tomography (OCT)-derived optic nerve head (ONH) parameters are associated with longer axial length (AXL) in healthy myopic eyes. DESIGN: Prospective cross-sectional observational study. METHODS: Two hundred eleven healthy eyes of 140 participants (96 emmetropic-mild myopic [AXL: 22.2-24.5 mm], 83 moderately myopic [24.5-26.0 mm], and 32 highly myopic [26.0-27.4 mm] eyes) were enrolled. Bruch membrane opening (BMO), anterior scleral canal opening (ASCO) area and ovality, minimum rim width, parameters defining misalignment between the BMO and ASCO planes, OCT-defined region of perineural canal retinal epithelium atrophy and externally oblique choroidal border tissue, circumpapillary retinal nerve fiber layer thickness (cpRNFLT), circumpapillary choroidal thickness (cpChT), lamina cribrosa parameters, and peripapillary scleral (PPS) angle were calculated from BMO-centered radial scans reconstructed from 3D raster scans. Multivariate linear mixed models were used to elucidate ONH parameters that are independently associated with AXL. RESULTS: Longer AXL was associated with a greater misalignment between ASCO and BMO planes, larger region of externally oblique choroidal border tissue, thinner cpChT, larger PPS angle, larger ASCO area, and thicker cpRNFLT (all P < .040 after Bonferroni's correction for number of included explanatory variables). CONCLUSIONS: A greater misalignment between BMO and ASCO planes, thinner choroid, a more posteriorly bowed PPS, an enlargement of ASCO, and thicker cpRNFLT were each associated with longer AXL. An enhanced understanding of these AXL-associated configurations should provide essential information to improve our ability to detect glaucoma-induced ONH morphology in myopic eyes.