Changes in Shape Discrimination Sensitivity Under Glare Conditions After Orthokeratology in Myopic Children: A Prospective Study.

Purpose: To investigate changes in shape discrimination under mesopic conditions with and without glare after orthokeratology in myopic children. Methods: This prospective study included 79 eyes of 79 myopic children (ages: 8-16 years). Shape discrimination thresholds (SDTs) were measured using radial frequency patterns, with a radial frequency of 4 cycles/360°, a peak spatial frequency of 3 cycles per degree, a contrast of 20%, and a mean radius of 1.5 degrees. SDT under mesopic conditions with and without glare was measured before orthokeratology and again at 1 week and 1 month after orthokeratology. Changes in the SDTs and their relationships to baseline ocular parameters were analyzed. Results: SDTs with glare decreased significantly at 1 week (-0.08 ± 0.15 log(arcsec), P < 0.001) and 1 month (-0.09 ± 0.15 log(arcsec), P < 0.001) after orthokeratology. SDTs without glare remained stable (P = 0.81 and P = 1.00, respectively). The difference between SDTs with and without glare also decreased significantly at 1 week (-0.10 ± 0.17 log(arcsec), P < 0.001) and at 1 month (-0.08 ± 0.18 log(arcsec), P = 0.001) after orthokeratology. Based on a multivariate analysis, the greater decrease in SDT with glare after 1 month of orthokeratology was associated with a higher baseline spherical equivalent refraction. Conclusions: Orthokeratology resulted in improved shape discrimination in myopic children under mesopic conditions but only when measured in the presence of glare.

[Hydrogen rich water attenuates pregnancy gingivitis induced by ligation in SD rats].

PURPOSE: To investigate the effect of hydrogen rich water on experimental gingivitis in SD rats during pregnancy. METHODS: Female SD rats mated with male ones were chosen to induce experimental gingivitis after ligation for 2 weeks. The pregnant rats were randomly divided into control group, model group and HW group. In the control and model group, rats were given pure water, while animals in the HW group were given hydrogen-rich water twice a day. All pregnant animals were sacrificed on day 16 of pregnancy. The level of Prog, SOD and TNF-α in the gingiva of different groups were measured by ELISA, the expression of PR, NFκB and TNF-α were determined by immunohistochemistry and Western blot. SPSS 13.0 software package was used for data analysis. RESULTS: Pregnancy gingivitis of SD rats could be induced by thread ligation. PR was mainly distributed in the gingival epithelium, while there was no significant difference of Prog and PR in the gingiva among different groups(P>0.05). Furthermore, in the model group, lower SOD level as well as higher NFκB and TNF-α level were found in the gingiva. Compared with the model group, the inflammatory response of pregnancy gingivitis in HW group was significantly suppressed along with decreased NFκB and TNF-α. CONCLUSIONS: Progesterone and its receptor may play an indirect role in the process of pregnancy gingivitis of rats. Hydrogen rich water may be beneficial in suppressing pregnancy gingivitis progress by decreasing inflammatory response related to gingival oxidative stress.