Corneal viscoelasticity differences between diabetic and nondiabetic glaucomatous patients

To investigate corneal viscoelasticity in primary open-angle glaucoma patients with and without diabetes mellitus, and to correlate corneal hysteresis (CH) with central corneal thickness (CCT).

In this cross-sectional study, 44 primary open-angle glaucoma patients [19 with diabetes (34 eyes) and 25 without diabetes (40 eyes)] underwent a complete ophthalmic examination. Data collected by masked investigators included CH and CCT using the Ocular Response Analyzer. The mean of 3 measurements was considered for each test. We analyzed the difference between the mean CH in both groups using a general linear model. Partial correlation coefficient between CH and CCT was also calculated.

Mean+/-SD age in diabetic and nondiabetic groups was 67.1+/-8.7 and 65.9+/-15.1, respectively (P=0.77). There was no significant difference regarding mean CCT between diabetic (531.7+/-31.3 mum) and nondiabetic (546.6+/-37.3 mum) groups (P=0.21). Patients with diabetes presented significantly higher CH values than patients without diabetes (9.1+/-1.9 mm Hg vs. 7.8+/-1.7 mm Hg, P=0.04). There was a significant and positive correlation between CH and CCT for all patients (r=0.407, P<0.001).

Primary open-angle glaucoma patients with diabetes have significantly higher CH values than those without diabetes. CH and CCT results were positively correlated. These findings merit further investigation to assess the role of different CH values on glaucoma evaluation and susceptibility.