Asymmetric stress distribution on lamina cribrosa in glaucoma patients with high myopia.

PURPOSE

To investigate the impact of biomechanical changes in the optic nerve head on glaucoma progression during ocular rotation in highly myopic eyes with primary open-angle glaucoma.

METHODS

This study retrospectively enrolled 147 patients with primary open-angle glaucoma, including 57 with high myopia and 90 with non-high myopia. Personalized optic nerve head models were designed, and simulations were performed using finite element analysis to evaluate the effect of ocular rotation on the optic nerve head. Biomechanical changes in the optic nerve head were analyzed and compared between the groups.

RESULTS

The mean strain on the lamina cribrosa was significantly higher in the high myopia group compared to the non-high myopia group during ocular rotation. The stress ratio, indicating asymmetric stress distribution, was higher in the high myopia group than in the non-high myopia group. The stress ratio increased significantly as axial length increased. Both stress ratio and mean lamina cribrosa strain were correlated with rate of retinal nerve fiber layer thickness reduction (stress ratio: partial coefficient = -0.171, P = 0.040; mean lamina cribrosa strain: partial coefficient = -0.196, P = 0.018).

CONCLUSION

High myopia leads to increased lamina cribrosa strain and asymmetric stress distribution during ocular rotation. These findings underscore the importance of considering optic nerve head biomechanics in patients with high myopia. Additionally, the stress ratio may serve as a novel indicator for predicting glaucoma progression.

KEY MESSAGES

What is known Biomechanical changes in the optic nerve head differ between patients with high myopia and those with non-high myopia. What is new Asymmetric stress distribution on the lamina cribrosa during ocular movement was higher in the high myopia group and was associated with structural progression of glaucoma. A longer axial length increased the asymmetric stress on the lamina cribrosa during ocular movement.