Predictors of Dexamethasone Response of Residual Edema by Branch Retinal Vein Occlusion after Bevacizumab Injection

Purpose@#To predict the response to intravitreal dexamethasone (IVD) implant injection in cases where macular edema (ME) caused by branch retinal vein occlusion persists despite intravitreal bevacizumab injection. @*Methods@#Three consecutive (monthly) bevacizumab injections were given to treat ME caused by branched retinal vein occlusion (BRVO) 63 eyes that received additional dexamethasone or bevacizumab injection 1 month later to treat residual ME were retrospectively studied. Each injection group was divided into two subgroups according to ME disappearance status by 6 months after diagnosis. Initial central retinal thickness (CRT), subfoveal choroidal thickness (SFCT), and hyperreflective focus status were compared among the subgroups, as were the changes in these values. @*Results@#At the decision point, the dexamethasone good response subgroups exhibited thicker CRTs and smaller CRT changes than the dexamethasone partial response subgroups (all p < 0.05). The good dexamethasone response subgroup showed smaller SFCT changes, a thicker CRT, and smaller CRT changes than the bevacizumab good response subgroup (all p < 0.05) at the decision point. The cutoff values of the Youden index were 409 μm for the CRT and 62.5 μm for the CRT change (p = 0.002 and p = 0.011, respectively). @*Conclusions@#If ME persists after three bevacizumab injections, IVD more effectively reduces edema if the CRT is thick or if the CRT change is small.

Effect of Nitric Oxide on the Permeability of Trabecular Meshwork Cell Monolayer

PURPOSE: To investigate the effects of nitric oxide (NO) on the permeability of cultured human trabecular meshwork cell (HTMC) monolayer. METHODS: HTMCs were cultured until confluency in the Transwell inner chamber and then exposed to 0, 10 or 100 microm S-nitroso-N-acetyl-DL-penicillamine (SNAP) and 0.5 mm L-NG-Nitroarginine methyl ester (L-NAME) for 24 hours. Permeabilities of carboxyfluorescein through the HTMC monolayer were measured using a spectrofluorometer after 2 hours in the outer chamber. Cellular viabilities and production of NO were assessed using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) and Griess assay, respectively. RESULTS: The cellular survival was not affected by 10 or 100 microm SNAP (p > 0.05) but NO production increased in a dose-dependent manner (p 0.05). CONCLUSIONS: NO increased the permeability of carboxyfluorescein through the HTMC monolayer in a dose-dependent manner. Thus, NO could increase trabecular outflow by increasing the permeability of trabecular cell layer in addition to trabeular messwork (TM) relaxation.

Wound Healing Effect of Bacterial Synthesized Cellulose on Full Thickness Skin Defect in the Rat

PURPOSE: Cellulose is a natural substance from plants or bacteria. It is known that bacterial synthesized cellulose has an effect of wound healing. The aim of this study is to show the effect of bacterial synthesized cellulose from citrus on wound healing. METHODS: Three full-thickness skin defects were made on the back of Sprague-Dawley rats. Three wounds were treated by vaseline gauze(Group V), Algisite M(R)(Group A) and bacterial synthesized cellulose from citrus(Group C) was used for dressing on skin defect on rats. We analyzed the gross, histological and biochemistry finding. RESULTS: Group C showed more decrease of wound size compared to Group V(33% versus 7.2#) after 14 days. The histologic findings revealed Group C and Group A preceed the process of wound healing rather than Group V(More rapid collagen deposition and neovascularization and reduced inflammation). Also, the expressions of vascular endothelial growth factor(VEGF) and transforming growth factor(TGF)-beta1 were increased in the Group C and Group A compared with the Group V in 7 days. VEGF and TGF-beta1 expression were decreased in the Group C and Group A in 14 days, however Group V was not decreased at 14 day because of delayed wound healing process. CONCLUSION: Bacterial synthesized cellulose from citrus affects wound healing by reducing the inflammatory stage. And stimulates wound contracture by the deposition of extracellular matrix, thus preventing the formation of chronic wounds.