Objective: To compare central corneal thickness (CCT) in patients with ocular hypertension (OH), primary open-angle glaucoma (POAG), glaucoma suspects and control subjects and to determine if there is a correlation between CCT and age.

Methods: Prospective study. Methods: CCT was evaluated in 50 eyes of 25 OH patients (mean age 52.4 +/- 1.6 yrs, x +/- Sx) who were allocated into group 1, in 26 eyes of 13 glaucoma patients (mean age 64.1 +/- 1.0 yrs)--group 2, 46 eyes of 23 glaucoma suspects (mean age 60.1 +/- 1.3 yrs)--group 3, and 144 eyes of 72 control subjects (mean age 61.4 +/- 0.9 yrs)--group 4. CCT was measured using an ultrasonic pachymeter (Pach IV, Accutome).

Results: The OH patients had a mean CCT of 582.88 +/- 5.51 microm. The mean CCT for the glaucoma patients was 552.38 +/- 5.90 microm, for the glaucoma suspects--551.04 +/- 4.23 microm and for the controls--549.47 +/- 3.07 microm. There was significant difference in age between group 1 and group 2 patients (P = 0.007) and between group 1 and group 4 patients (P = 0.001). CCT in the eyes with OH was significantly greater than that in POAG eyes (P = 0.003), in glaucoma suspects eyes (P < 0.001) and in control eyes (P < 0.001) (ANOVA, with Bonferroni correction).

Conclusions: The comparative evaluation of CCT in patients with OH, POAG, glaucoma suspects and controls shows that CCT is the thickest in patients with OH. There is a correlation between CCT and age--younger patients possess thicker corneas. Our results suggest that CCT should be taken into account when assessing the risk for the development of glaucoma in OH patients.