Central corneal thickness in patients with normal-tension glaucoma

To compare the central corneal thickness of eyes with proved normal-tension glaucoma with that of eyes without glaucoma.

A prospective study.

The study included 30 consecutive patients with normal-tension glaucoma (60 eyes, group I), and 30 age- and gender-matched non-glaucoma patients (60 eyes, group II). Central corneal thickness was measured using an ultrasonic pachymeter (Pach IV, Accutome). The mean central corneal thickness of normal-tension glaucoma patients and controls were compared using independent samples t-test.

The mean (+/- SD) central corneal thickness of normal-tension glaucoma and non-glaucoma patients was 517.4 +/- 19.2 microm and 549.0 +/- 39.4 microm, respectively. There was a significant difference in this parameter between the groups (P < 0.001). The mean intraocular pressure was higher in glaucomatous eyes (17.1 +/- 2.3 vs. 16.3 +/- 1.4 mm Hg, P = 0.028). The visual acuity in normal-tension glaucoma eyes was lower than that in controls, but the difference failed to reach statistical significance (P = 0.069).

The results indicate that corneas of patients with normal-tension glaucoma are thinner than those of non-glaucoma patients.