Change in corneal hysteresis over time in normal, glaucomatous and diabetic eyes.

ABSTRACT

PURPOSE: Corneal hysteresis (CH) is lower in glaucomatous eyes. The aim of this study was to determine and compare the change in CH over time between normal, open angle glaucoma (POAG) and diabetic subjects. METHODS: We retrospectively analysed records of patients undergoing assessment with the Ocular Response Analyzer (Reichert, Corp., New York, NY, USA). Right eyes with at least 7 measurements were included. Patients with ocular pathology other than POAG were excluded. Two-sample t-tests, chi-squared and logistic regression were used to analyse data. RESULTS: A total of 1418 normal and 322 POAG patients were included. Patients with POAG were significantly older (70.73 ± 11.33 vs. 61.59 ± 16.56 years; p < 0.001), had a longer follow-up (4.14 ± 1.34 vs. 2.72 ± 1.49 years; p < 0.001) and had lower CH (9.58 ± 2.17 vs. 9.95 ± 2.19 mmHg p = 0.01), but there were no gender differences between groups (61.5 vs. 57.7% female; p = 0.21). We observed a significantly greater decrease in CH among patients with POAG (-0.11 ± 0.73 vs. 0.07 ± 2.31 mm Hg/year; p = 0.02). The relation between ∆CH/year and diagnosis persisted after adjusting for age and follow-up time (OR 0.90; 95% CI 0.82, 0.99; p = 0.03). We found CH to be higher in diabetics vs. non-diabetics (10.34 ± 2.04 vs. 9.88 ± 2.19; p = 0.02), but ∆CH/year was not different (0.07 ± 1.27 vs. 0.03 ± 2.10; p = 0.77). CONCLUSIONS: Patients with POAG in this study had a significantly greater rate of CH decline compared to normal. There was no significant difference in rate of CH change in diabetic and non-diabetic patients.