Purpose: The aim of this study was to evaluate whether glaucoma was related to central corneal thickness (CCT). Methods: The Beijing Eye Study 2006 is a population-based study that included 3251 (73.3%) Subjects (aged 45+y) Out Of the 44)9 subjects who had participated in the Survey in 2001, and who returned for a reexamination. The main outcome measures were central corneal thickness and presence and progression of glaucomatous optic neuropathy. Results: Measurements of CCT were available for 3100 (95.4%) subjects. CCTs did not vary significantly (P > 0.10) between the "optic disk glaucoma" [n = 78 (2.5%) subjects 551 +/- 32 mu m], the "perimetric glaucoma" [n = 38 (1.1%) subjects: 550 31 pin]. and the normal groups (n = 3022; 556 +/- 33 mu m). The CCT was not significantly associated with the neuroretinal rim area (P = 0.28) or the mean visual-field defect (measured by frequency-doubling perimetry) (P = 0.22). 111 multiple regression analysis. the CCT was significantly associated with male sex. (P < 0.001). urban region (P < 0.001), and intraocular pressure measurements (P < 0.001); whereas it was not significantly (P = 0.17) associated with chronic open-angle glaucoma. During follow-ups from 2001 to 2006, 42 Subjects, who showed a progression of, or development of glaucomatous abnormalities of the optic nerve head did not differ significantly (P = 0.30) in CCTs from the stable group. Conclusions: CCTs might not be markedly different between glaucomatous and normal eyes. The reasons for the discrepancies between the present population-based study and previous hospital-based investigations might be due to the differences in study design and mode of selection of study participants.