Effect of Deep Optic Nerve Head Morphology on Lamina Cribrosa and Peripapillary Scleral Configurations in Healthy Eyes.

PURPOSE: The purpose of this study was to investigate the relationship among deep optic nerve head (ONH), lamina cribrosa (LC), and peripapillary sclera (pSc) configurations in healthy eyes.

METHODS

This prospective cross-sectional study included 205 healthy eyes of 141 subjects. Multivariable linear mixed models identified factors associated with LC curvature index, prelaminar thickness (PLT), pSc angle, and LC depth (LCD). Explanatory variables included age, gender, intraocular pressure, axial length (AXL), visual field sensitivity, disc area, disc ovality, disc torsion, Bruch's membrane opening (BMO)-minimum rim width (MRW), BMO and anterior scleral canal opening (ASCO) area, peripapillary zone area with and without Bruch's membrane (PPZ+BM/-BM), and peripapillary choroidal thickness (pChT). A sub-analysis was conducted by dividing the eyes at the median AXL.

RESULTS

LC curvature was flatter in eyes with large PPZ-BM, long AXL, and shallow LCD (P = 0.002, P = 0.015, and P = 0.042, respectively). Similar factors exhibited consistent effects in longer AXL eyes, whereas different factors, BMO-MRW, ASCO-area, and pSc-angle, were associated in shorter AXL eyes (P = 0.006, P = 0.012, and P = 0.018. respectively). PLT was thinner in eyes with thin BMO-MRW, large ASCO area, and young age (P < 0.001, P < 0.001, and P = 0.009, respectively). The pSc angle was steeper in eyes with long AXL and large PPZ+BM (P < 0.001). LCD was deeper in eyes with thick pChT, thin BMO-MRW, and small ASCO area (P < 0.001, P < 0.001, and P = 0.004, respectively).

CONCLUSIONS

Novel associations between LC configurations with scleral canal size, PPZ+BM/-BM, and BMO-MRW were found after correction for confounding deep ONH morphologies. Given that these structures are associated with glaucomatous changes, these inter-structure correlations should be considered when distinguishing LC changes between healthy and glaucomatous eyes.