Lamina Cribrosa Defects and Optic Disc Morphology in Primary Open Angle Glaucoma with High Myopia

Purpose: To investigate whether lamina cribrosa (LC) defects are associated with optic disc morphology in primary open angle glaucoma (POAG) eyes with high myopia. Methods: A total of 129 POAG patients and 55 age-matched control subjects with high myopia were evaluated. Three-dimensional scan images obtained by swept source optical coherence tomography were used to detect LC defects. Radial B-scans and infrared images obtained by spectral domain optical coherence tomography were used to measure beta-peripapillary atrophy (PPA) lengths with and without Bruch's membrane (BM) (temporal, nasal, superior, and inferior), tilt angle (vertical and horizontal), and disc diameter (transverse and longitudinal). Peripapillary intrachoroidal cavitations (PICCs), disc area, ovality index, and cyclotorsion of the optic disc were analyzed as well. Results: LC defects were found in 70 of 129 (54.2%) POAG eyes and 1 of 55 (1.8%) control eyes (P < 0.001). Age, sex, spherical equivalent, axial length, intraocular pressure, and central corneal thickness were not significantly different among POAG eyes with LC defects, POAG eyes without LC defects, and control eyes. Temporal PPA lengths without BM in all three groups correlated significantly with vertical and horizontal tilt angles, although no PPA length with BM correlated significantly with any tilt angle. PICCs were detected more frequently in POAG eyes with LC defects than those without LC defects (P = 0.01) and control eyes (P = 0.02). POAG eyes with LC defects showed a smaller ovality index (P = 0.004), longer temporal PPA without BM (P < 0.001), and larger vertical/horizontal tilt angles (vertical, P < 0.001; horizontal, P = 0.01), and transverse diameter (P = 0.01). In multivariate analysis for the presence of LC defects, presence of POAG (P < 0.001) and vertical tilt angle (P < 0.001) were identified as significant. Conclusions: The presence of LC defects was associated with myopic optic disc morphology in POAG eyes with high myopia.