Elevated lamina cribrosa-sclera interface stress in glaucomatous eyes with optic disc haemorrhage.

BACKGROUND/AIMS

To investigate the biomechanical mechanisms underlying the occurrence of optic disc haemorrhage (ODH) in glaucoma by analysing the stress at the lamina cribrosa (LC)-sclera interface using patient-specific finite element models based on clinical data.

METHODS

This was a retrospective, single-centre, simulation-based, case-control study. Finite element simulations were conducted on individualised optic nerve head models under two gaze conditions: primary gaze and 10° ocular rotation (adduction). The von Mises stress was calculated at the anterior and posterior boundaries of the LC-sclera interface. Intergroup differences in stress and their association with clinical variables were evaluated using analysis of variance, correlation and regression analyses.

RESULTS

A total of 111 eyes were included: 44 eyes with primary open-angle glaucoma (POAG) and ODH, 34 eyes with POAG without ODH and 33 control eyes. We found statistically significant differences in stress at both the anterior and posterior boundaries during adduction between the POAG with ODH group and the other groups (p<0.01). Age and axial length were positively associated with stress at the temporal LC-sclera interface during adduction. Logistic regression identified adduction-induced stress as significantly associated with ODH. The multivariate analysis identified age as the strongest contributor to stress during adduction.

CONCLUSION

This study demonstrates that increased stress at the LC-sclera interface may contribute to the occurrence of ODH in glaucoma during adduction in the temporal region. We also found that ageing and longer axial lengths may increase stress, potentially leading to the disruption of small vessels at the optic nerve head.