Central Corneal Thickness and Glaucoma in Adult Chinese: the Beijing Eye Study

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 4439 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 microm], the "perimetric glaucoma" [n=38 (1.1%) subjects; 550+/-31 microm], and the normal groups (n=3022; 556+/-33 microm). 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). In 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.