Subfoveal choroidal thickness. The Beijing eye study

Purpose To study the subfoveal choroidal thickness(SFCT) in adult Chinese and its correlation with ocular biometric parameters, ref. error, and age Methods A detailed ophthalmic examination was performed including SD‐OCT with enhanced depth imaging for measurement of SFCT Results SFCT measurements were available for 3233 (93.2%) subjects.Mean SFCT was 253.8 ± 107.4μm (range: 8μm to 854μm).In multivariate analysis, SFCT was associated with younger age(P<0.001; correlation coefficient r:4.12; beta coefficient: 0.37),shorter axial length (P<0.001;r:44.7;ϐ:0.46), male gender (P<0.001;r:28.5;ϐ:‐0.13), deeper anterior chamber depth (P<0.001;r:39.3;ϐ:0.13),thicker lens (P<0.001;r:26.8;ϐ:0.08),flatter cornea (P<0.001;r:46.0;ϐ:0.11) and better best corrected visual acuity(logMAR;P=0.001;r:48.4;ϐ:0.06). In multivariate analysis, SFCT was not significantly associated with blood pressure, ocular perfusion pressure, intraocular pressure, cigarette smoking, alcohol consumption, serum concentrations of lipids and glucose, diabetes mellitus and arterial hypertension. In the myopic refractive error range of more than ‐1 diopters, SFCT decreased by 15µm(95% CI): 11.9, 18.5) for every increase in myopic refractive error of one diopter,or by 32µm (95%CI: 37.1, 26.0) for every increase in axial length of one millimeter. For each year increase in age, the SFCT decreased by 4.1μm (95%CI: 4.6, 3.7) (multivariate analysis). Conclusion SFCT with a mean of 254±107μm in elderly subjects with a mean age of 65 years decreased with age(4µm per year of age) and myopia(15 µm per diopter of myopia). It was additionally associated with male gender and the ocular biometric parameters of a deeper anterior chamber and thicker lens. The association between SFCT and BVCA strongly points towards a functional aspect of SFCT