Purpose: To determine how the translaminar pressure difference (TLPD) and gradient (TLPG) influence the position of anterior lamina cribrosa (LC) surface.
Methods: Twenty-six eyes of 26 healthy subjects were subjected to enhanced-depth imaging volume scanning of the optic nerve using spectral-domain optical coherence tomography (SD-OCT). The anterior LC surface depth (LCD) relative to the Bruch's membrane (BM) opening was measured at 11 equidistant planes, and the LC thickness (LCT) was measured at three locations (superior midperipheral, midhorizontal, and inferior midperipheral). Intraocular pressure and lumbar cerebrospinal fluid pressure (CSFP) were measured on the same day as the SD-OCT examination. The TLPD was defined as the difference between IOP and CSFP (i.e., IOP-CSFP), and the TLPG as the TLPD divided by LCT (i.e., TLPD/LCT).
Results: Subjects were aged 63.4 ± 8.0 years and comprised 12 males and 14 females. Regression analyses revealed a significant association between a larger mean LCD and male sex (P = 0.002), and between a larger central LCD and male sex (P ≤ 0.012), larger TLPD (P = 0.048), and higher TLPG (P = 0.029). There was no significant association between IOP, CSFP, and LCT, and either the mean LCD (P = 0.438, 0.368, and 0.416, respectively) or central LCD (P = 0.284, 0.085, and 0.144, respectively).
Conclusions: A larger central LCD was associated with larger TLPD and higher TLPG in healthy eyes, which indicates that the translaminar pressure dynamics may play a role in the position of the anterior LC surface relative to BM opening in healthy human eyes.