Lower corneal hysteresis is associated with more rapid glaucomatous visual field progression.

AIM

We investigated the correlation between central corneal thickness (CCT) and corneal hysteresis (CH) and their relationship with the rate of visual field (VF) change.

METHODS

Glaucoma patients who underwent complete ophthalmic examination and tonometry using both the Goldmann applanation tonometer and the Ocular Response Analyzer were prospectively enrolled. Only eyes with ≥5 SITA Standard 24-2 VF tests were included. Automated pointwise linear regression analysis was used to determine VF progression. One hundred fifty-three eyes (153 patients; mean age, 61.3 ± 14.0 y; mean number of VF, 8.5 ± 3.4; mean follow-up time, 5.3 ± 2.0 y) met the enrollment criteria.

RESULTS

The mean global rate of VF change was -0.34 ± 0.7 dB/y. Twenty-five eyes (16%) reached a progression endpoint. Progressing eyes had lower CCT (525.0 ± 34.2 vs 542.3 ± 3 8.5 μm, P=0.04) and lower CH (7.5 ± 1.4 vs 9.0 ± 1.8 mm Hg, P<0.01) compared with nonprogressing eyes. CH and CCT correlated significantly (r=0.33, P<0.01). By multivariate analysis, peak intraocular pressure [odds ratio (OR)=1.13 per mm Hg higher, P<0.01], age (OR=1.57 per decade older, P=0.03), and CH (OR=1.55 per mm Hg lower, P<0.01) remained statistically significant.

CONCLUSIONS

Corneal biomechanical and physical properties, such as CH and CCT, are highly correlated and associated with VF progression. As CH may describe corneal properties more completely than thickness alone, it may be a parameter that is better associated with progression.