Correlation between axial length and the elasticity of the posterior segment of eyeball in myopic eyes without posterior staphyloma: a shear wave elastography-based cross-sectional study.

PURPOSE: To investigate the correlation between axial length (AL) and the elasticity of the posterior segment wall of the eyeball using shear wave elastography in myopic eyes without posterior staphyloma.

METHODS

This cross-sectional study enrolled 87 right eyes, including 29 with high myopia (spherical equivalent ≤ -6.00 D) and 58 with low myopia (-6.00 D < spherical equivalent ≤ -0.50 D). The AL measured with Pentacam and the elasticity of the eyeball wall at different locations (including the macular region, near the optic nerve, and near the midperiphery) could be reflected using shear wave elastography. Multivariate regression analysis was used to explore the correlations between AL and elasticity at different locations.

RESULTS

A significantly lower elasticity measurement was observed in high myopia group at the macular region, 3.5 mm from the nasal side of the optic nerve, temporal and nasal sides of the optic nerve, and temporal and nasal sides of the midperiphery in both horizontal and vertical directions (P < 0.01). Furthermore, the elasticities at the macular region in both horizontal and vertical directions had significant correlations with AL (P < 0.001).

CONCLUSION

The elasticity of the eyewall at the macular area decreased with an increase in AL, which may explain why posterior scleral staphyloma is most likely to occur at the macular area. The macular area should be paid more attention in high myopia. These microstructural changes indicated by the difference in elasticity of the posterior segment wall maybe lead to the progression of posterior staphyloma.