Abstract
Purpose:
Growing evidence points to morphological features of lamina cribrosa and optic disc being important pathogenesis of glaucoma and myopic neuropathy. We performed a cross sectional clinical study to evaluate the vertical asymmetry of the lamina cribrosa (LC) tilt angles (LCTA) from the Bruch’s membrane opening (BMO) and investigate related factors.
Methods:
Thirty glaucomatous (17 patients) and 29 non-glaucomatous (16 subjects) eyes were enrolled. Optic nerve head B-scans were obtained using optical coherence tomography (OCT) with a wide bandwidth femtosecond Mode-locked Laser. Lines were drawn from the superior temporal (ST) to inferior nasal (IN) and from the inferior temporal (IT) to superior nasal (SN) directions (±45-degree rotated with horizontal line), and the angle between the BMO plane inner edge and approximate best-fitting line for the anterior LC plane was measured as LCTA.<br />
Results:
The median (interquartile range, [IQR]) ST to IN LCTA (ST-LCTA) and IT to SN LCTA (IT-LCTA) were 3.0 (1.8-4.7) and 9.2 (6.6-6.4) degrees, respectively, in non-glaucomatous eyes, and 3.3 (2.5-6.4) and 11.0 (5.3-18.6) degrees, respectively, in the glaucomatous eyes. IT-LCTA was significantly greater than ST-LCTA (p < 0.001) and correlated with refractive errors after adjustment for other factors in both normal and glaucomatous eyes. (p < 0.001).
Conclusions:
The differences show the vertical asymmetry of LC tilting from BMO plane, and these novel parameters have important implications for investigation of the correlation between myopia, glaucoma, and morphological lamina features.