A Prospective Longitudinal Study to Investigate Corneal Hysteresis as a Risk Factor of Central Visual Field Progression in Glaucoma

Abstract

Purpose: To evaluate the role of corneal hysteresis (CH) as a risk factor of central visual field (VF) progression in a cohort of glaucoma suspect and glaucoma patients.

Design: Prospective cohort study.

Methods: Two hundred forty-eight eyes of 143 subjects who were followed for an average of 4.8 years with a minimum of 5 visits with 10-2 and 24-2 VF tests were included. Univariable and multivariable linear mixed-effects models were used to identify characteristics associated with the rate of change over time in 10-2 and 24-2 mean deviation (MD). Mixed-effects logistic regression was used to evaluate characteristics associated with an increased likelihood of event-based 10-2 VF progression based on the clustered pointwise linear regression criterion.

Results: CH was significantly associated with 10-2 and 24-2 VF progression in the univariable trend-based analysis. In multivariable trend-based analyses, lower CH was associated with a faster rate of decline in 10-2 MD (0.07 dB/y per 1 mm Hg, P < .001) but not with 24-2 MD (P = .490). In multivariable event-based analysis, lower CH was associated with an increased likelihood of 10-2 VF progression (odds ratio = 1.35 per 1 mm Hg lower, P = .025). Similar results were found in eyes with early glaucomatous damage at the baseline (baseline: 24-2 MD ≥ -6 dB).

Conclusions: Lower CH was associated with a statistically significant, but relatively small, increased risk of central VF progression on the 10-2 test grid. Given the substantial influence of central VF impairment on the quality of life, clinicians should consider using CH to assess the risk of progression in patients with primary open-angle glaucoma including those with early disease.

Figure 1.

Distribution of baseline corneal hysteresis measurements for all 248 eyes included in the study of the relationship between corneal hysteresis and central visual field loss during follow-up.

Figure 2.

Zonal rates of change (dB/year) in 10-2 test grid are compared between eyes with baseline corneal hysteresis < 10 mmHg (A, 147 eyes) and those with baseline corneal hysteresis ≥ 10 mmHg (B, 101 eyes). Darker areas correspond to faster rate of visual field progression.