Differences in ocular biometry between urban and rural children matched by refractive error: the Shandong Children Eye Study.

PURPOSE: To determine the differences in mean ocular dimensions between urban and rural children and identify possible influencing factors. METHODS: This work uses previously published data from the Shandong Children Eye Study, which was based on a random cluster sampling applied to a cross-sectional school-based study design in the rural Guanxian County and Weihai city. All children underwent auto-refractometry and biometry under cycloplegia. RESULTS: The study included 3290 children (aged 9.35 ± 2.93 years), consisting of 888 pairs of boys and 757 pairs of girls matched by sex, age and refractive error (each pair matching one child from urban cohort with one from the rural cohort). Overall urban children were significantly taller and heavier than rural children (t-test; p < 0.001), which was confirmed for all age groups for weight. Urban ocular axial lengths were significantly longer by 0.23 mm compared to the rural population (t-test; p < 0.001), mostly in younger children and boys. Meanwhile, corneal curvatures were flatter in the urban cohort by 0.08 mm (p < 0.001). This association of axial length with urban vs rural region was reduced in magnitude by 69.7% after accounting for height. CONCLUSIONS: For the same, matched refractive error, children from urban regions had significantly longer eyes and flatter corneal curvature than rural children. Since corneal curvature is defined during the first 2 years of life, early environmental factors may be the source of these differences in ocular dimensions.

Influence of Yanyankang Powder on Th1/Th2 in rats with experimental autoimmune uveitis.

OBJECTIVE: To study the influence of Yanyankang powder on Th1/Th2 in rats with experimental autoimmune uveitis (EAU). METHODS: The EAU models were induced in Lewis rats by immunization with interphotoreceptor retinoid binding protein (IRBP) 1177-1191 in complete Freund's adjuvant. The rats were randomly divided into 3 groups: a model control group, a Yanyankang group, and a prednisone group, 9 rats in each group. The model control group was intervened with saline solution by gavage. The Yanyankang group was intervened with Yanyankang powder 4 g/(kg day) by gavage. The prednisone group were intervened with prednisone acetate tablets 5 mg/(kg d) by gavage. All groups were intervened after immunization once every 2 days for 18 days and monitored by slit-lamp biomicroscopy daily until day 18. The levels of gamma interferon (INF-γ) and interleukin-10 (IL-10) in the supernatants of T cells were determined by enzyme-linked immunosorbent assay. Polymerase chain reaction (PCR) technology was used for measuring Th1 and Th2 related cytokine mRNA expressions. RESULTS: Slighter intraocular inflammation was found in the Yanyankang group and the prednisone group than the control group. The levels of the IFN-γ and IL-10 in the supernatants of the spleen lymph node cells were 382.33±6.30, 155.87±4.46 µg/L in the Yanyankang group and 270.93±7.76, 265.32±11.88 µg/L in the prednisone group. Both had significant differences compared with the control group (941.53±8.59, 20.67±4.65 µg/L; =0.01). The PCR results showed the same tendency. CONCLUSION: Yanyankang powder showed favorable effects in the rats with EAU by influencing the function of Th1 and Th2 cells.