It has been suggested that the lamina cribrosa displacement due to increased intraocular pressure (IOP) may result in the obliteration of its foramina, causing a compression of the optic nerve axons and leading to glaucomatous damage. Moreover, it has been suggested that susceptibility to lamina cribrosa displacement may be related to low corneal hysteresis (CH), which has been identified as a risk factor for glaucoma, given the anatomical continuity between the cornea, sclera and lamina cribrosa.
In this prospective observational study, the authors have investigated the influence of baseline CH on lamina cribrosa displacement over time as determined using spectral- domain optical coherence tomography (SD-OCT). The authors controlled for the potential confounding effects of several covariates in three multivariate models: adjusting for age, choroidal thinning, central corneal thickness (CCT), and average IOP in the first; adjusting for peak IOP, age, choroidal thinning, and CCT in the second; and adjusting for age, choroidal thinning, CCT, and IOP change during follow-up in the third. In all three models, baseline CH was significantly associated with a posterior displacement of the lamina cribrosa during follow-up. Each mmHg of lower CH was associated with 0.75 microns/year of posterior displacement (95% confidence interval (CI): 0.07-1.42) in model 1, 0.73 microns/year (95% CI: 0.06-1.39) in model 2 and 0.66 (95% CI: 0-1.32) in model 3. Lamina cribrosa displacement was also associated with choroidal thinning , but neither age, baseline CCT, or average IOP were significantly correlated with it.
This study provides solid evidence that lower baseline CH is associated with an increase in the posterior displacement of the lamina cribrosa over time, a finding that highlights the potential role of this biomechanical parameter as an independent risk factor for glaucoma onset and progression
To sum up, this study provides solid evidence that lower baseline CH is associated with an increase in the posterior displacement of the lamina cribrosa over time, a finding that highlights the potential role of this biomechanical parameter as an independent risk factor for glaucoma onset and progression.