Correlation between Lamina Cribrosa Tilt, Myopia and Glaucoma Using Optical Coherence Tomography with a Wide Band Femtosecond Mode-locked Laser.

Abstract

Morphological features of the lamina cribrosa (LC) and optic disc may play an important role in the pathogenesis and progression of glaucoma. Optical coherence tomography (OCT) is a non-invasive optical imaging modality that allows real-time structural imaging of the fundus. We developed an OCT system using an ultra-broadband Kerr lens mode-locked Ti: Sapphire laser and a wideband spectrometer. The depth resolution into the tissue was measured as less than 2.0 μm. Advances in OCT technology have enabled detailed examinations of the deep optic nerve head (ONH), including LC. When measuring LC tilting to conduct a clinical evaluation of ONH, the termination point of Bruch's membrane, Bruch's membrane opening (BMO) is used as a reference point. The vertical and horizontal angles between BMO line and approximately the best-fitting line for the surface of the LC were measured and potential associated factors were estimated. The horizontal internal LC tilt angle was correlated with refractive errors, corresponding to myopic physiological changes, and vertical internal LC tilt was correlated with glaucoma, corresponding to glaucomatous pathological changes. These parameters have important implications for investigating the correlation between myopia, glaucoma and LC morphological features.