Purpose: To investigate peripheral lamina cribrosa depth (PLCD) and its vertical-horizontal difference in eyes with primary open-angle glaucoma (POAG).
Methods: Patients with POAG (n=90 eyes) and age-matched healthy individuals (n=90 eyes) underwent swept-source optical coherence tomography (SS-OCT) scans centered at the optic discs. The PLCD was defined as the vertical distance between the most peripheral visible end of anterior lamina cribrosa (LC) surface and the reference plane connecting the Bruch's membrane openings. The PLCD in each quadrant region and the vertical-horizontal PLCD difference were compared between the POAG and healthy eyes. The clinical factors associated with increased PLCD were evaluated.
Results: The PLCD was significantly larger in the POAG eyes than the control eyes at the horizontal (P=0.034) and vertical (P=0.001) meridians. The vertical PLCD was significantly larger than the horizontal PLCD, both in the POAG eyes (P<0.001) and in the control eyes (P=0.003). However, the vertical-horizontal PLCD difference was significantly larger in the POAG eyes (47±60 μm) than in the control eyes (18±54 μm, P=0.001). Multivariate regression showed a significant association of male gender (P=0.005), increased baseline IOP (P=0.043), and decreased MD of VF (P=0.025) with increased PLCD.
Conclusions: The peripheral LC was displaced more posteriorly in the POAG eyes compared with the age-matched healthy eyes. In the POAG eyes, the peripheral LC was displaced more posteriorly at the vertical meridian than at the horizontal meridian. The peripheral LC in the vertical meridian might have increased IOP-related strain (deformation) compared with horizontal meridian in glaucomatous eyes.