Subfoveal choroidal thickness of Chinese aged over 50 years and patients with diabetes mellitus and glaucoma

Objective To investigate the subfoveal choroidal thickness ( SFCT ) and its relationship to associated diseases , including diabetes mellitus , diabetic retinopathy , and glaucoma.Methods The population-based cross-sectional Beijing Eye Study 2011 included 3 468 individuals with a mean age of (64.6 ±9.8 ) years.A detailed ophthalmic examination was performed including spectral-domain optical coherence tomography with enhanced depth imaging model (EDI SD-OCT).246 patients with diabetes and 128 patients with glaucoma were enrolled in the study.Statistical analysis was performed by SPSS 20.0 to examined the mean values of SFCT and the prevalence rate of associated diseases ; an univariate and multivariate linear regression to analyse the relationship between SFCT and ocular or general factors .Results Mean SFCT was ( 253.8 ±107.4 )μm.In multivariate analysis , SFCT was significantly associated with younger age(b=-4.12, P<0.001), shorter axial length(b=-44.7, P<0.001), male gender(b=-28.5, P<0.001), deeper anterior chamber depth (b=39.3, P<0.001), thicker lens(b=26.8, P<0.001), flatter cornea(b=46.0, P<0.001) and better best corrected visual acuity (b=-48.4, P=0.001).Mean SFCT in diabetes mellitus group was (266 ±108) μm.In multivariate analysis, SFCT was significantly related to presence of diabetes mellitus (b=21.2, P=0.001); but neither presence (P=0.61) nor stage (P=0.14) of diabetic retinopathy was significantly associated with SFCT.Mean SFCT in glaucoma group was (201.4 ±102.4.1) μm.Mean SFCT in glaucoma group was (201.4 ±102.4.1) μm;for open angle glaucoma , mean SFCT was ( 210.1 ±104.7 ) μm; for primary close angle glaucoma , mean SFCT was (184.2 ±93.6 )μm.In multivariate analysis, SFCT was significantly associated with close angle glaucoma(b=-32.3, P=0.04), but was not related to open angle glaucoma (P=0.44).Conclusions Mean SFCT was ( 253.8 ±107.4 )μm.SFCT was increased with age and myopic refractive error; and associated with male gender , anterior chamber depth , lens thickness , flatter cornea , best corrected visual acuity.SFCT in patients of diabetes mellitus was slightly thicker than normal people ; but the presence and development of diabetic retinopathy were not related to SFCT.SFCT in patients with close angle glaucoma was thinner than control group;but for open angle glaucoma , SFCT was similar to the normal people. Key words: Diabetes mellitus ;  Diabetic retinopathy ;  Glaucoma ;  Choroid ;  Tomography,optical coherence ;