Link between corneal biomechanical factors, glaucoma severity appears weak

This prospective study in the March issue of the American Journal of Ophthalmology examined the association between corneal biomechanical parameters and glaucoma severity. The results indicated only a weak relationship between corneal hysteresis (CH) and corneal resistance factor (CRF) and structural and functional damage in glaucoma patients.

The authors analyzed visual field results and retinal nerve fiber layer (RNFL) thickness measurements using both spectral-domain optical coherence tomography and GDx ECC (scanning laser polarimetry with enhanced corneal compensation).

Subjects were 191 patients with confirmed or suspected glaucoma (299 eyes). The authors report that CH and CRF were positively associated with more severe visual field damage in univariable analysis. But after adjusting for central corneal thickness, age and axial length, the relationship of CH and CRF to RNFL thickness no longer reached statistical significance and only CRF remained independently associated with mean deviation and pattern standard deviation.

Further study is warranted to determine if the corneal biomechanical properties of CH and CRF provide any value in the diagnosis and management of glaucoma and to investigate the relationship between corneal biomechanics and long-term glaucoma progression risk.